AudioCircle
Other Stuff => Archived Manufacturer Circles => Promitheus Audio => Topic started by: robert1325 on 17 May 2007, 02:39 pm
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So has anyone listened to this DAC? Looks very nice! :thumb:
http://www.promitheusaudio.com/dac.htm
(http://www.promitheusaudio.com/dac/DAC-SS.JPG)
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I believe rollo has one on the way to him (I think the tubed version).
I'm also waiting feedback on this DAC. Seriously pretty d... sure it will be incredible :drool:, I should just order it but can not make up my mind, Nick's pieces are in a state of constant upgrades :D.
Feedback from the first owner will make me move, trying to get the TVC and DAC at the same time. We need to keep this thread on the front page. This DAC will certainly cause a stir, I think it will completely over shadow the Paradisa :o, lets hope I'm right and @ 340. + shipping.
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Robert1325 and 1000a,
Nick told me the tube DAC is a slight improvement with tube characteristic of warming sound (just for $765.00 compared to $405.00 included shipping fee). I will keep updating with the SS DAC which is coming next week if rollo has not a chance to listen first. In my opinion the most important components in Promitheus DAC are once again the C-core output transformers which will be amazing and astonishing since I never listened to any DACs so far with this type of trannies.
Tan
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I'm ordering one for my computer with usb. My current cd player was modded to use a transformer based analogue stage to great effect, so I'm hoping the promitheus dac will sound good.
What type of tubes does the tubed version use? The website lacks any information on it.
Biggie.
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Tan
is the C core definitely in this DAC?
is yours due next week w C core trans?
is yours gonna be the SS DAC?
and Rollo's the tubed version?
thanks,
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Didn't know the Promitheus DAC used C-core output transformers, thought they where M60 or something ... This makes me even more excited ! From what I've read about C-cores so far. The tubed dac is a bit to expensive for my liking , 'this dac might replace my Bolder Squeezebox 2 if it's good enough :thumb:
I'm looking forward to yours and rollo's comments!
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The website says "This output transformer is wound on a M6 core".
Biggie.
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From what i've heard Nick is now experimenting with C cores & others....if the current models use M6 that might change soon.
Nick is all about bang for the buck. Seems like now he's heading right into the 'Bang' category now though! a good thing for sure.
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CC CCcooore look what you've done to me....... :lol:
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What type of tubes does the tubed version use? The website lacks any information on it.
Nick told me and he always likes Russian 6N1P (equivalent to 6922 or 7308 tubes) since it has neutral sounding and maintains sonic signature of the DAC. If you have tube DAC you can roll tubes with more excitment especially if your gears are all solid states. :thumb:
is yours due next week w C core trans?
1000a,
I am sorry for making mistake to tell you my DAC has C-core output transformer. They are wounded only on M6 core with 0.05mm laminate. That is good enough for now since C-core costs more for the labor. I am excited to compare to my existing DAC too.
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Will C-core output transformers be an upgrade option?
Biggie.
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Biggie
here is a link to a comment on that, also a good thread to follow on Nick's stuff. see rollos coments on the page, also if you keep abreast of his posts it is helpful cause he is the person who seems to know the most and is even going to visit Nick in a week or so.
i am also hoping for a C core in the DAC, I do not change gear often (had my used birdland DAC since 2002, and it is still quite good) and once i do I just forget the upgrade stuff, other than DIY things. So when I buy componets I want to make sure i am making a substantial improvement.
http://www.audiocircle.com/index.php?topic=31621.msg366754;topicseen#new
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anybody got theirs yet? :drool:
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Hey Guys,
The DAC uses M6 cores which are very good and priced right. The "C" core trannies will be utilized in a new line of components which will be a announced when all testing is complete and the line is finalized.
I can only imagine what Nicholas has up his sleeve. The base products as we know them perform well above their price range. With a possible Statement series with the best parts available and Nicholas' expertise in circuit design I can't wait. I am especially interested in the GM70 SET amp and DAC. Deihavilland sells their GM70 amp for $10,000+ and Lamm for $126,000! The Promitheus line will most likely be more expensive then we are used too form them as the parts are, but knowing Nicholas the price will be fair. Not like the others.
The future looks bright at Promitheus. Let the Sun shine in.
rollo
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Who has ordered (if you'd let us know) and are waiting for a Promi DAC to arrive either SS ot tubed? Are we (and me) all waiting each others feed back and no one has ordered one? :scratch:
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There are few who had order the dac.
and we are in the midst of working on them. I hope to get them out at the end of this week
From there, i hope to hear back what other thing about it
Cheers
Nicholas
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Has anyone ordered it with the USB option? It would be great to compare USB vs a good transport...
Looking forward to your impressions! I might order one for my movie sound.
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Hi Promitheus Fans,
I have ordered a SS DAC but Nick told me he just have an engraving tool or machine and wants to engrave his company name on my DAC. Nick said that my Promitheus SS DAC will be shipped out this week but he did not inform what day(?). So I am still waiting for it. Will let you guys know after it is breaking in. Please be patient. aa
Tan
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Me too, I have ordered the Apollo and SS Dac, same as you guys, still waiting and will compare with my heavily modified GG preamp and Lite Dac 50 later.
Andis
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we should change the topic title to "promitheus dac, everyone?" :wink:
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:drool: :drool: :drool: :drool:
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1000a,
There are no news so far. Nick told me he will send mine out on Friday last week(they have just built half way?). Hopefully I will get it by this week but not sure!!!! :sleep:
Tan
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Anyone recieved their unit yet?
Biggie.
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any updates?
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I do not receive mine yet and do not know what is happened? It has been one month and 21 days already. Ask rollo maybe you find out something!!??
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Me too, Nic said still have some trouble with the labeling/engraving.
Hi Nic, any good news for us?
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Hi Gents,
I got the Promitheus DAC today and will bring it home to fire it up tonite. Inside the DAC it is looked very professional handcraft and installation. I have a copper wire wounded pulse transformer (even though I ordered the silver wired one) on both BNC and RCA digital connection through a switch. There is no on/off switch and light indicator (based on Nick opinion without them the DAC sounds better). Let see how the DAC sounds and I will let you know before and after 100 hours break-in time. :D
Tan
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pics, pics, pics... lets see.
btw, do you have a paradisea to compare it to?
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I am listening to the DAC right now. I will take pictures later on and will do comparison next week with F100 Paradisea (I do not have Paradisea). The Promitheus DAC should have 100 hours breaking in. So far I am impressed with warm rounded with details in midrange. It needs to have a deep firm punchy bass after breaking in and with some tweaks like footers according to Nicholas.
Tan
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Tanchiro58,
Glad to hear its in the house. Let it burn in for the same time as TVC. The trannies are very similar and require about 400 Hrs. This sucks as we all know but worth every minute of time. Even with 30 Hrs on it compared to the Paradisea with WE 396 the Promitheus clearly was better.
good luck and Enjoy!
rollo
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I am glad it finally showed up, long wait. was it 2 months? :scratch:
Anyway I am thrilled you got yours I wish I had ordered the base model a while back but I let the endless improvements mentioned online keep me from ordering either the TVC or DAC. I ordered a monarchy NM24 that has a SS DAC and a Tube DAC in it so I can run just my powered sub with the SS DAC and the mid to top with the tube DAC.
So I can not wait to hear your feed back on the Promi DAC, keep us posted with any feeling you get even before full burn in.
On another thread I will do a full report on the NM24, I am sure people will have some interest in this one also. God I hope I am not a person about to have 3-4 DACs and then lose $$ selling the non keepers on agon. :duh:
I am starting to break my own guide to audio - maximize my $$$ (get the 95%), I have got my system really dialed in w room treatments and such and my used Birdland Odeon Lite I have had since 2002 does not disappoint me in the least. Everthing really sounds incredibly good. Lots air, great bass, detail, punch, large stage, and musical, so why did I just spend $$, I guess I gotta find out am I really near that 95% or still a good deal off.
I will know shortly! Once that law of diminising returns kicks in strongly, I really don't like spending stupid $$! Maybe the base SS DAC and base TVC would have been the way to fly, as long as I stay off the audio forums I could keep them 4 yrs check back in and replace with the latest base model.
I am turning into one of those people :?
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1000a.....
This may be of interest to you....LINK... (http://www.positive-feedback.com/Issue25/monarchy_m24.htm)... :thumb:
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HeY Wolf
Thats exactly why I jumped
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Nothing wrong with having a few DAC's.... 8)
They really all do sound different....a nice variety for whatever your mood.... :thumb:
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Plus the Altmann GB seems to be 5% off :(,
Also I read extensively on Lynn Olson's website, he seems to really really know his stuff.
His rev. of the M24 is pretty exciting, so I guess I am exploring. No free lunch can't explore without food!
So I am simply doing what everybody does taking a chance and listening for myself. :o
the bird was my first so I am probably in the small spenders group :lol:
thanks for the link,
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1000a....
So I am simply doing what everybody does taking a chance and listening for myself.
Good.....thats the way to do it...happy listening.... :thumb:
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Hi tanchiro58
"So far I am impressed with warm rounded with details in midrange. It needs to have a deep firm punchy bass after breaking in and with some tweaks like footers according to Nicholas"
Are you meaning that this DAC tends to a warm and soft side? Not punchy enough from some rock/dynamic music? How about the definition and soundstage?
How does it compare to your modded MHDT Renaissance II?
Since you have got your DAC, I believe my Apollo and DAC will be arrived soon. :D
Andis
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Plus the Altmann GB seems to be 5% off :(,
?! can you elaborate, i don't get it
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Plus the Altmann GB seems to be 5% off :(,
?! can you elaborate, i don't get it
Hi anubisgrau, sorry
What that refers to is there were or are a group (GB- group buy) who were trying to do a group buy on the Altmann attraction DAC hoping to save some money, (at least 15% off) but as I read the thread it turned out with shipping hassels the most they could save was maybe 5% off per DAC. I believe by the time I did the battery and the minimum options I wanted it was 1500+ minimum and then shipping.
I hope this makes sense, the 2 on my short list were the Altmann and the Promi tube DAC.
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I posted this on the Paradisia thread, in response to something-anyway I think it makes sense over here also, Go Nick :D (updated slightly)
this only realtes to 2 channel audio-what they are doing in HT world, could not tell ya.
Well Tan has the Promi DAC in his system and is burning it in now so we who are always curious and searching will be enlightened shortly on an extremely affordable NOS SS DAC that should be quite excellent. it should certainly be seriously an easily considered.
I have been using a Birdland since 2002 that is an Up-sampler, that I have been quite pleased with it bumps 16/44 k to 24/96. But it has been my only external DAC so I have not heard the others yet- so my research has been limited to reading others feelings on the sound of the different ones. But I have put in effort trying to have a basic understanding of how they work or at least the intension behind them.
I am trying an Oversampler this time and in short order and I have every intention to also try a NOS DAC in the future, that way i can have a good feel for how they each sound to my ears.
Oversamplers do not bring 16/44 up to 24/96, its just a different design than NOS its goal is the same more pure - get back to our roots kinda thing. the 2 camps will argue their respective positions I will let my ears pick my gear. Any of the 3 can sound good it depends on implimentation and design.
The promi is low risk, super price and if its Nicks I am sure it sounds quite good, doubt few people but the very pickiest would be disappointed.
1-early CDPs were NOS 1982 about
2-nxt gen were Oversamplers i believe these began in 1985ish
(x2,x4,x8 oversample to help improve the the sound)
3-then came the Upsamplers (as a reaction to the seeming DVD-A and SACD revolution to bump 16/44 CDS to 24/96 to maybe sound as good as the new formats), some love it some don't.
Some experts say a transport for DVD-A and SACD is really not at all optimal for CD sound, for what thats worth, although they are available and on the highend also. Everything REdbook/CD now is being reavaluated cause Up-sample DACs were a reaction to SACD/DVD-A, which most agree by this time is essentially a failure, not bad sound but company wars and few music choices have taken a large toll.
Now we are in the best time of all a true vortex and a crossroads where many have found really good redbook/cd can be better than DVD-A or SACD (it had potential it looks like a Betamax kind of market problem and with this its still so new we have not even learned to begin taping the possibilities there cause with the new formats came new bigger more difficult math problems, and the CD math problems have still yet to be really well solved). So now really good designers are using any of the 3 DACs but from a different vantage point. They all have the window of history and all the accumilated knowledge/experince and even newer technology to re-explore with and implimiment from.
So the NOS of today is not the NOS of 1982-3, its cutting edge and the oversampling today is also much better informed also. they all sound different and anyone of them can sound very good. its a party, not a problem :D
From what i understand many get Up and Oversample confused (my self included, hense this post as a check point, I am sure I do not have this perfect) they are similar very losely in technique - application in the math of the design (which is infact quite complex is also different), but the intended outcomes are quite different, no matter the math. 1- (upsample) to get to 24/96 from 16/44 2- (oversample) - to rec what ever comes in the door and spit it out at the same type of #'s (despite messing w it). 3-(nos) has the same goal as #2.
Few people agree whats better, so there is no better. From the really expensive stuff, one company Dodson uses I believe at one point at least both Over and Upsampling in the same DAC, Levinson generally uses Oversampling and Audio Note uses NOS w transformers (like Nick's DACs)in their really good stuff, all can work well, depends on who's driving the buss.
The really interesting thing I am waiting to hear is how the Promi SS NOS (using Trannies in its design) compares to the SS NOS Altmann (which could be considered extremely pure in its design).
Many agree the Altmann is incredibley good, smooth analogue and is killing lots of compititors up to 3,000. quite easily. So will the 340. Promi SS NOS kill the 1,500. Altmann SS NOS (guessing the price here). For me this will be the test. Its the super bowl for the budget audiofile.
Hope all this helps rather than confuses- that was my intention, I am trying to get a simple working understanding of each, for my own clarity. OK carefull with those's :flame:'s this is how I understand it, thus far.
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Are you meaning that this DAC tends to a warm and soft side? Not punchy enough from some rock/dynamic music? How about the definition and soundstage?
Andis,
The sound of my Promitheus DAC is very very punchy with every notes (I listened to Hotel California of Eagles I like it much more than my modded MHDT Renaissance II which leans more to soft site and no punchy sound at all).
I like the most of this DAC when I listen to a guitar musics (electric or acoustic) the notes of a musician fingers on strings are clearly noticed without brightness (mostly in electric guitar). Besides vocals like deep voice of Patricia Barber and Diana Krall are more impressive than before.
The sound leans more to rounded warm sound but not lack of details and punchy (it needs more hours break-in to produce a deep punchy bass but not overhanged based on user's guide and rollo).
I think Nick has designed this DAC for you guys musics but he also tried to mix match little bit on warm side but clear and clean for asian or oriental musics. However, it is depending on your transport or CDP or SB3 and your digital cable too and your whole system (do you have SS or tube gears?).
Soundstage is wide opened in your listening area but not spread to everywhere in your room (I am not sure of this since I just installed the Eighthnerve rectangles and corners in my room). In my opinion the best way to check the soundstage of your system is you seat on one spot you like also when you step out of the room or go to the next room which share same wall with your music room. If you like the sound in the three locations I just mentioned you can conclude that your system is good to excellent.
I can not tell you about the comparison between modded Renaissance II and Promitheus DAC since the Promitheus DAC still needs more time to break-in. But I can tell you the Renaissance (tube) has more lush sound which I like in some of my musics than Promitheus (non-tube). Who knows after a couple weeks later. I will let you know then.
I hope you will get the Apollo and DAC soon. You will enjoy your synergistic system. Have a good listening. :thumb:
Tan
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thanks Tan I can not wait to hear more from you as the time clicks away and continues to open up the Promi DAC. :D
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Hi tanchiro58
Tks for the prompt reply. Please let us know more about the DAC after broken in.
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Have there been anymore updates regarding this dac??
I sent Nicholas an email looking for some internal information about the dac including receiver chip and other opamps used and have heard no reply. I am also interested in the advancements of the c core trannie.
Any help would be appreciated here.
Thanks
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some pics of the unit would be great also. his site only shows the inside. anyone?
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some info came out on the "TVC passive anyone thread" recently , I believe Nick said he is using the TDA 1545 phillips, I have not seen any pictures other than that 1 image. it should look alot like the TVC box very similar I am told. :scratch:
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some internal information about the dac including receiver chip and other opamps used
goskers,
I can see in my Promitheus DAC that Nick uses CS 8414 receiver chip and two Phillips TDA 1545A NE5534 (I do not know why two?). The opamps I did not pay attention their brands. M3 Output transformers C-cores trannies he will use in Statement tube DAC and it is not available yet. You can order one in advance since it will take more than two months.
anthony a.,
The SS DAC body looks like the TVC you have except it has an IEC, a switch for BNC or RCA digital input which is not shown in his picture and a pair of RCA ouputs. Once again it does not have an on/off switch and a light indicator. I wish I can take pictures of my DAC but I gave my digital camera to my brother.
To everyone is interested my Promitheus SS DAC is in 6 days break-in time the sound is more focus and less harsh (bright and dry sound at the beginning). It is now more smoother especially sweeter in the midrange, punchier and deep bass noticed (it is depending to your digital cable also).
I have a chance to test with two different digital cables (one is a good coper one and other DIY pure silver of audio consulting wire). The copper has more body and punchier. The silver is more musical, softer but more deep bass. Both have big soundstage. I still have more time to let the DAC breaking in (let's say one more week).
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Another DAC to use this chip. Now DIY Paradise uses the TDA 1545 in their Monica II, MHDT in the Paradisea and Constantine as well as Ack Industries in their dAck!.
Maybe one chip is used for each channel, or maybe in parallel like the LIte Audio DAC-AH.
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Have there been anymore updates regarding this dac??
I sent Nicholas an email looking for some internal information about the dac including receiver chip and other opamps used and have heard no reply. I am also interested in the advancements of the c core trannie.
Any help would be appreciated here.
Thanks
Goskers
I might have miss your email on this. IF you can resend that would be great
Here are the chips use
CS8414 Crystal
TDA1545 Philips
NE5534 Philips
The power supply transistors are
l7805, l317, l337, bc546 and bc556
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some internal information about the dac including receiver chip and other opamps used
goskers,
I can see in my Promitheus DAC that Nick uses CS 8414 receiver chip and two Phillips TDA 1545A NE5534 (I do not know why two?). The opamps I did not pay attention their brands. M3 Output transformers C-cores trannies he will use in Statement tube DAC and it is not available yet. You can order one in advance since it will take more than two months.
anthony a.,
The SS DAC body looks like the TVC you have except it has an IEC, a switch for BNC or RCA digital input which is not shown in his picture and a pair of RCA ouputs. Once again it does not have an on/off switch and a light indicator. I wish I can take pictures of my DAC but I gave my digital camera to my brother.
To everyone is interested my Promitheus SS DAC is in 6 days break-in time the sound is more focus and less harsh (bright and dry sound at the beginning). It is now more smoother especially sweeter in the midrange, punchier and deep bass noticed (it is depending to your digital cable also).
I have a chance to test with two different digital cables (one is a good coper one and other DIY pure silver of audio consulting wire). The copper has more body and punchier. The silver is more musical, softer but more deep bass. Both have big soundstage. I still have more time to let the DAC breaking in (let's say one more week).
The brand of the opamp is important, it is made by Philips. I tried 4 different 5534 and the philips are far superior here. why 2 opamps. Simple when you merge the left and right channel signal into 1 opamp you would lose channel separation, imaging and soundstaging. However what a manufacture gains is cost. You would have less power supply decoupling, the 2 opamps have their own dedicated power supply to decouple them from the master power supply and plus soldering the extra components .
For me i would not make that compromise. So that is why you have 2 opamps
The DAC is a transparent piece of equipment, so whether you use BNC or RCA or your digital cable you can hear alot of difference.
have you tried out mechanical spikes? i use my ebony cones here .The dac loves the proper isolation just like the tvc. Also bear in mind the DAC is a fully loaded transformer piece that means longer burn in time than normal. Also like the TVC i notice the first few hours the sounds changes a far bit too
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have you tried out mechanical spikes? i use my ebony cones here .The dac loves the proper isolation just like the tvc. Also bear in mind the DAC is a fully loaded transformer piece that means longer burn in time than normal.
Nick,
I place the three pieces of wood footers between the DAC and a Delrin Acetale Black platform and notice a big change. I just wrapped the three transformers and all wires with ERS sheets and found the sound is more focus and sweeter even though the break-in time is slightly over 100 hours. :guitar: :dance:
Tan
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Tan
I need your personnel image so that i can send you the picture of the power cord i use with my current DAC
I am glad you find the cones helps
Now to buy some ERS sheets , and try that i out
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last two(2) i 've got a Promi's DAC personally delivered by Nic by himself.
this is the 2nd piece of gear which i've got from Nic besides the reference version of the TVC which remains as a gem in my
humble system.
It has been run-in for a day now ~ i was really impressed with the result of the Promi's DAC with my JVC DVD player. The current setup is JVC DVD Player --> Promi's DAC--> Promi's ref. TVC --> DIY Kit KT88 (running in triode) --> Rogers Ls3/5a
I played my favourite track "what the world needs now" by Stacey Kent. The immediate effect i got is the piano sound has fuller-bodied and weight ~ i can even feels the piano decay effects after each note which i didn't encounter before this. Not to mention the soundstage has increased tremendously. When she beginning to sing "... what the world needs now.... " the sibiliance which used to exist is entirely gone !!! AMAZING!!! my heart continously flow with the music...
The 2nd track which i've played is Jheena Lodwick-perhaps love ~ the sound of the guitar strokes is more obvious and body to it.At the middle of the track ... "... perhaps love... " the snare drum simultaneously surface on the song at the background with good timing.
Then i swap to Celine Dion-Where is the love.
i must mention the hand drum has improvement on the depth and the triangle which i've not heard before this ! I also got more bass ~i changed my mind not getting any AB1 subwoofer .
i also attached a picture of the internal Promi's DAC as for yr reference. The upgrades are V-Cap and AuriCap for + supply~ which is well-worth spent.
Ok can't get to listen to another of my favourite track..
Tsai Chin- "Du Ko" (Ferry) A famous Taiwanese Singer.. tho i really don't understand much Chinese yet i still enjoy this very much especially MUST be with the Promi's DAC !
Nic, thank you very much as i really enjoy it ~ hope you can drop by more often and listen for yrself to see how's this Promi's DAC gets better and better daily.
(http://i198.photobucket.com/albums/aa37/hanchun/PROMI_DAC.jpg)
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Just a FYI on that PS, I ordered some black hold pad back on June 19th and it still hasn't shipped from speaker city. I emailed them about it and was informed that "BH products are on back order for 5 days.". That email was sent on the 27th so I wouldn't expect my order to be fulfilled for a few days...and I ordered a lot.
Long story short if you order some it may take a extra week or so to get it because of the back order / my impulsiveness.
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I had to wait about 3 weeks the last time I ordered from Speaker City as well. Seems like we need a new supplier of the magic material.
If anyone wants a small amount of it though, lemme know. I still have 2 whole sheets i may not ever use.
damping the transformers in my TVC was a ridiculous tweak, and the improvement certainly was in the bass department, but not at the expense of other sonics...
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I've only applied BHP under a huge plate amp tranny, not under my TVC's. From what i've read about BHP, it was deisgned to go under trannies though.
i placed it on the 3 exposed sides of my TVC trannies, covering the metal shield around the winding. I used 3 indiv 1" wide strips, it wouldn't hurt to use thinner pieces though. a little BHP goes a long way.
If you've ever done a tweak that immediately enhances the bass performance, but didn't seem to affect other areas, but after a day or 2 of settling it seems like everything is improved...that's more or less what i'm talking about. Too often i've done small things that improved the bass and somehow this improved everything else. So, now when i tweak i listen for the bass and assume the rest will fall in line. to date, it always has.
i'd give your DAC 3-4 weeks of burn-in before tweaking a thing though. every new piece of 'whatever' that i've bought in this hobby has always taken a month - 400 hrs. as we found out with the TVC's, its those trannies that take time to sweeten up. Let 'em cure and then tweak your heart out!
When you get around to this, do the power tranny first. i'll assume that vibes the most. kinda crazy that the tweak works on the TVC. but, i may just be damping that metal shield...dunno know.
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Gooberdude,
Thank you for your quick reply.
I had the DAC about a week. In the first couple days it had nice warm rounded sound but after that suddenly the sound has changed to harsh and dry. I did wrap the PS and output trannies with ERS cloth and hope will cure the problems . Listened again the sound was smoothing out and even clean and clear with more details. It last only two days and the harsh and bright sound was coming back again. Therefore, I had to reduce from 2V to 1V gain (first time I see in the DAC). Now it is going back to normal like before. So what is your suggestion?
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I've never found ERS to do anything but deteriorate analog signals, it seems to help when used in power and sections and digital chips etc. I'd try removing the paper from your output transformers and see if that helps clean your signal back up again!
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I totally agree with Gordy, ERS can muck things up in a big way. It works well inside my power strip though, so i do think its great for AC applications, but terrible anywhere close to an audio signal is passing through. I've not owned a DAC though, and lots of folk say ERS can aid them...
I think you're best bet is remove the ERS and just wait out the burn-in...let the DAC play when you are at work and sleeping to speed it up. Occasionally i've heard issues like you have, where the goodness fades in and out...but i think that's just a nasty artifact of burn-in. patience really is the key with new gear, assuming you don't have a burn-in machine.
no matter if its a tiny rca connector, speaker cables, pc's or gear...i always give it a month to settle.
I'd shoot Nick an e-mail and ask him too...
i'm considering buying some kind of burn-in device, maybe hagerman's. the wait is just so painful!
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Gooberdude,
Thank you for your quick reply.
I had the DAC about a week. In the first couple days it had nice warm rounded sound but after that suddenly the sound has changed to harsh and dry. I did wrap the PS and output trannies with ERS cloth and hope will cure the problems . Listened again the sound was smoothing out and even clean and clear with more details. It last only two days and the harsh and bright sound was coming back again. Therefore, I had to reduce from 2V to 1V gain (first time I see in the DAC). Now it is going back to normal like before. So what is your suggestion?
Good going with the dac. Hope you have lots of fun with it.
Don't get all hyper during the burn in process. A premature amelioration would just disguise the sound and not really improve it in the long run. You must wait for the burn in process to have it's eventual effect. We all wait it out. Usually a component is heavy on the bass at first. Then the highs get all tizzy. This will go on back and forth till it settles. Nothing can change that. You don't even need music burning in continuously for a month. A few hours each day will do the trick. Once the month is clear you could fiddle by tweaking.
Ers paper is really good at taming power conditioners. With transformers its a mixed bag. Trial and error. A good explanation on burn in is on this page: http://www.skywireaudio.com/tech.php
look up: Using Skywire Audio cables and Skywire Cables Design Theory
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Hey Guys,
What digital cable and powercord are you using with DAC? We have found that the SteroVox cable works quite well. If you have any suggestions feel free to tell us all.
rollo.
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What digital cable and powercord are you using with DAC? We have found that the SteroVox cable works quite well.
rollo,
I have tried quite a lot RCA and/or BNC digital cables. It is all depending on your CDP or SB3 and DAC you are using and also the most important factors are your preamp, amp and ICs. I have experimented so far three different RCA digital cables Harmonic Tech Cyberlink Platinum (copper), Audio Consulting (silver) and Homegrown (copper). The best one in my system is HT Platinum and second best is Silver Audio Consulting. I am connecting them between modded SB3 and Promitheus DAC. I will try the Stereovox VX2 and Blue Jeans (BNC)and Zu Ash (RCA).
I have used a custom made PC but Nick will send me his own built PC (only for the Promitheus DAC).
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I do not have NOS Paradisea DAC but I listened to it before from my friend. So I can not answer and help you to solve your troubleshooting of your DAC. Let the experts do the job.
In my opinion, the sound of Paradisea was not impressed (using TDA1545A) even though I have MHDT Reneaissance II (using TDA1543) which I did not like the sound in the first couple weeks. But I still love the analog sound of it after couple modifying tips in the signal path. I have had good impression with TDA1543 DAC chips since they sound more analog than 1545A (to me it is analytical). However, after listening to Promitheus SS DAC (using parallel TDA1545A or each channel has one chip-I am not sure) I have a good impression with TDA1545A. It sounds very very analog especially with vocals with seperation and decays (it is still in a break-in time). In other words, the Promitheus DAC so far is the best DAC I have owned before including NOS, oversampling and upsampling DAC. Thumbs up
We will have a comparison between Paradisea and Promitheus DACs this weekend at my house. So I will let you know.
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Hi Tan,
Glad to hear the good comment from you, is the DAC also good in playing music such as 1812, Firebird, Carmina Burana, heavy metal kinds of music?
Regarding the digital cable, heard that Blue Jeans, Ack! The digital connect and Bolder Cable company are using Belden 1695A to make the digital coaxial cable. From other forum, it is better than Zu Ash (RCA) but with a much cheaper price.
Cant wait to hear the digital cables review from you.
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What digital cable and powercord are you using with DAC? We have found that the SteroVox cable works quite well.
rollo,
I have tried quite a lot RCA and/or BNC digital cables. It is all depending on your CDP or SB3 and DAC you are using and also the most important factors are your preamp, amp and ICs. I have experimented so far three different RCA digital cables Harmonic Tech Cyberlink Platinum (copper), Audio Consulting (silver) and Homegrown (copper). The best one in my system is HT Platinum and second best is Silver Audio Consulting. I am connecting them between modded SB3 and Promitheus DAC. I will try the Stereovox VX2 and Blue Jeans (BNC)and Zu Ash (RCA).
I have used a custom made PC but Nick will send me his own built PC (only for the Promitheus DAC).
Hi Tan,
Make sure to include my silver plate DIY digital cables in your shootout too. I like to hear how my DIY cable stack up against the high price cables.
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Make sure to include my silver plate DIY digital cables in your shootout too. I like to hear how my DIY cable stack up against the high price cables.
Yes another good new to know for anyone who use SB3 or CDP with an external decent DAC that F100 just make his own DIY BNC digital cable. I have tried in my system and it makes my musics more lively and more layers but not lack of bass (my system seems to have little bottom before).
I have compared with other RCA and BNC digital cables it sounds much better than my other favorites in the price range of $150-200. The sound is neutral, sweet, musical and revealing especially with vocals...I think I am going to keep this cable for my future reference.
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Regarding the digital cable, heard that Blue Jeans, Ack! The digital connect and Bolder Cable company are using Belden 1695A to make the digital coaxial cable. From other forum, it is better than Zu Ash (RCA) but with a much cheaper price.
highdfever,
Ask F100 to send a 30 days trial of his DIY digital cable. I am sure you will like it more than Blue Jeans. This cable beats my HT Platinum (RCA) and it has more weight and smoother than Stereovox VX2 sonically. I will test it against the Zu Ash in a few days.
is the DAC also good in playing music such as 1812, Firebird, Carmina Burana, heavy metal kinds of music?
I am sure you will like the Promitheus DAC like I do right now. It passed 400+ hours. We had a rave for a Promitheus DAC at my house last night and my friend who owned a modded AN 3.1 DAC. He finally told me the Promi DAC sounds almost the same to AN 3.1 DAC. I am shock and think this is a real biggest bang for a less buck. :thumb:
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Hi Tan,
Glad to hear the good comment from you, is the DAC also good in playing music such as 1812, Firebird, Carmina Burana, heavy metal kinds of music?
Regarding the digital cable, heard that Blue Jeans, Ack! The digital connect and Bolder Cable company are using Belden 1695A to make the digital coaxial cable. From other forum, it is better than Zu Ash (RCA) but with a much cheaper price.
Cant wait to hear the digital cables review from you.
highdfever,
Carmina Burana ~ this is one of the best which i've heard in nic's system ~ GM70 Amp, C-Core TVC, SS DAC !
With the Promi's SS DAC the Soundstage is wide open ~the enchantment vocal, i can feels as if its 3D Soundscape. Not to mention, it has dynamics w/o losing control. You gotta experience this yrself.. !
i am still in the process of burn-in~ its such a pain-staking processs .. bout 80 hours now.
Tanchiro58,
Great to hear great reviews from yr side ~ i did not know that this thread has been moved. Have you manage to do the bypass cap. upgrade modification ? its one of the biggest improvement i've heard up to today.
the v-cap does alot of improvement but the x-tra auri-cap for the power supply stage i've yet to find out whether it makes any differences till i remove it this coming weekend as it needs time to burn in to make a difference as well.
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Have you manage to do the bypass cap. upgrade modification ? its one of the biggest improvement i've heard up to today.
AudioFreak,
I am waiting Nick's pics of close up where he soldered his Mundorf bypass caps in the DAC. Based on your pics I can see and do it but I have to make sure.
My DAC has passed 400+ hours break-in I believe. But still it has little bit up and down sound. In general it sounds the way I have expected in my system. I am beginning to replace some pure copper silver plated wires that I got in hand from pcb to output trannies and trannies out to connectors. It sounds way better than stock wires.
Good to hear your new improved system. :thumb:
Tan
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What digital cable and powercord are you using with DAC
rollo,
How are you doing?
I found that Zu Ash RCA digital cable matches pretty good between my modded SB3 (with pulse transformer SC947-02) and Promitheus DAC. The sound is smooth, punchier, revealing and very liquid (like tube sound).
audioFreak,
How are the results of your modification with V-caps and Auricaps? Nick told me he modified with Mundorf 0.1uF bypassed the Panasonic Gold and the sound has more body. I did replace the two Sanyo caps with BG 1000uF/16V and all the wires around the two output trannies and installed some BHP on and underneath the trannies. There is a big improvement sonically. I tried to do the bypass caps but it is hard to solder on the surface of pcb. Therefore, I will do underneath the pcb.
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Tanchiro,
Did the promi/paradisea comparison happen this past weekend? If so, how'd it go?
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Tanchiro,
Did the promi/paradisea comparison happen this past weekend? If so, how'd it go?
gitarretyp,
It was a comparison while the Promitheus DAC had not fully broken in yet. To my knowledge and opinion, if you listen to vocal jazz the modded Paradisea has more lush and mellow sound (it was connected to my all tube system but for SS system you should question F100). After a couple modifying like replace with BG caps and silver plated pure copper wire from and to output trannies the Promitheus DAC sounds more like a tube DAC, more decays, details and layers with a punchy bass and sweet midrange. Based on my taste I think the stock Promitheus DAC will bestout the stock Paradisea in a couple months. :thumb:
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I agree with Tanchiro58 that the Promitheous DAC was not fully broken in when I had it at my place. The soundstage is wide but not quite focus yet. Other than that, it sounds very nice overall. However, I prefer the lush sound of my Paradisea DAC.
When I returned the Prometheous DAC to Tanchiro58, I got a chance to listen to it again in his tube system and it sound very musical. I guess the bottom line is you have to listen to it in your own system and form your opinion from there. It's all about system synergy. :)
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F-100, What did you end up using in your modified Paradisea? opa2107 or lm4562? Did you use Paper in oil caps?
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F-100, What did you end up using in your modified Paradisea? opa2107 or lm4562? Did you use Paper in oil caps?
Currently, I'm using stock opamp and vintage WestCap (spelling???) PIO caps. I also tried Mundorf Silver/Oil caps but it was too bright for my taste.
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Is there a source for the west-caps other than ebay?
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I got mine from Tanchiro58 and he got them from Ebay. They are hard to come by too.
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... I have experimented so far three different RCA digital cables Harmonic Tech Cyberlink Platinum (copper), Audio Consulting (silver) and Homegrown (copper). The best one in my system is HT Platinum and second best is Silver Audio Consulting. I am connecting them between modded SB3 and Promitheus DAC....
Hi, I used the HT Cyberlink Platinum a few years back with a Modwright P-3A/P-1A/P3 combo and it outperformed the digital cables from Audioquest and Transparent Audio that I tried. It was a very fast, open and airy cable with excellent detail and decays. However, it was a 110 ohm silver cable, not copper.
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I also tried Mundorf Silver/Oil caps but it was too bright for my taste.
I believed Mundorf caps are good for coupling. PIOs are best for output and/or coupling. Once again it depends on individual taste and synergistic system.
However, it was a 110 ohm silver cable, not copper.
Good to know this. Thanks DSK.
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any more updates?
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I am ordering mine today. I chose the balanced output package so I can eventually have a totally balanced system. The pre reportedly sounds better balanced, so I wanted that capability eventually.
AF
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It is generally accepted that clock jitter below 200ps rms is inaudible; although there are some who claim to hear as little as 2ps. Most S/PDIF receivers have <200ps jitter. So, the question is: Why would a DAC designer deliberately increase clock jitter by orders of magnitude, as is the case with asynchronous reclocking, and why doesn’t anybody hear it?
Asynchronous reclocking interposes latches in between the S/PDIF receiver and the DAC chip to reclock the data, bit clock, and word clock signals. The presumed purpose is to reduce jitter but that is preposterous. Asynchronous reclocking actually increases jitter.
In simplest terms, a latch or flip-flop is a digital circuit with two inputs, CLK and D, and one output, Q. Whatever binary value is present on the D input when CLK changes from low to high, is transferred to the Q output and held there until the next low to high transition of CLK. Regardless of the timing of changes at the input D, the output Q will change only when CLK transitions from low to high.
The usual implementation of asynchronous reclocking connects the CLK inputs of three latches to the reclock oscillator, the three D inputs to the data, word clock, and bit clock outputs of the S/PDIF receiver, and the three Q outputs to the respective data, word clock, and bit clock inputs of the DAC chip. (In actual practice, the latches have to be doubled, making six latches in total, to avoid an undesirable phenomenon called the meta-stable state. Conceptually, each double latch operates as a single latch.)
Ideally, the sample clock should be exactly 44.1KHz and the period of each and every clock cycle should be exactly 1/44100 seconds. But all oscillators have jitter, some more than others. With 200ps rms jitter expected in the S/PDIF sample clock, most clock periods will be too long or too short by 280ps rms. With asynchronous reclocking, each sample period will be an integral number of reclock periods and will be too long or too short by as much as a full reclock period. Because the clocks are asynchronous, an integral number of reclock periods will never equal the desired sample period. Reclocking with 100MHz, as the Prometheus DAC does, increases sample clock jitter, as seen by the DAC chip, to more than 5.7ns rms. 5.7 nanoseconds is considerably larger then 200 picoseconds!
Forcing the sample clock to be an integral number of asynchronous reclock periods will increase the granularity of the clock jitter. Instead of 22.675736961ns, the sample period is either 22.67ns or 22.68ns, +/- a few picoseconds. As a result, the effective sample rate jumps between two different frequencies, 44.09KHz and 44.11KHz, with a very predictable pattern. When the sampling frequency changes so does the frequency of the reconstructed audio signal. In other words, the changing sample frequency modulates the frequency of the audio signal.
It’s like wow and flutter. Perhaps that’s why some listeners report that asynchronous reclocking sounds more ‘analog-like’, meaning it sounds like a cheap turntable. Pitch stability is one area where digital audio is superior to analog. Why negate that benefit with asynchronous reclocking?
One more thing: I think the Prometheus web site is a real hoot. They make a big deal that the “clock module is place below the PCB to prevent spraying the board with noise.” That’s nice, but chances are the clock module is a ready-made oscillator hermetically sealed in a metal box. It’s hard to imagine a better electrostatic shield. Meanwhile, the reclocking latch, which is directly clocked by the reclocking oscillator, is mounted on top of the PCB and located a few centimeters from the DAC chip. The latch is encapsulated in plastic and its long bond wires, which traverse the entire length if the chip package, act as antennas spraying the DAC chip with RFI. What’s more, the eight latches, clocked simultaneously with only single VCC and ground pins located at diagonal corners and the decoupling cap located at the wrong end of the chip, will produce considerable ground bounce, which will add significant noise to the ground plane.
I can’t tell from the photo but I’ll bet the reclocking latch is a 74AC374 or equivalent. The 74AC logic family is well known for ground bounce and noise. When 74AC was developed, ground bounce was not well understood. More recent CMOS logic families are specifically designed to minimize ground bounce and noise that plagued earlier high-speed logic.
If all you golden ears think the Prometheus DAC is the best you have every heard. What can I say? Ignorance is bliss. Enjoy.
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If all you golden ears think the Prometheus DAC is the best you have every heard. What can I say? Ignorance is bliss. Enjoy.
Awww but it's mommy still loves it no matter what you say :lol:
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And you have heard this DAC? What did you compare it to? What do you have in your system? Have you designed DACs? Which commercial DAC is out there that you designed and built? How does it sound? Is anyone buying what you have to offer?
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I've been listening to the promitheus dac for about a week now. It probably has between 50-60 hours on it. I bought it to compare it to a modded DAC-AH which I unchasissed and screwed to a wood base. I've liked the sound of it but couldn't resist Nicholas's new creation. Preliminary impressions are that the promi has a wider and deeper soundstage, better detail, resolution and dynamics than the DAC-AH. It retains the tonal character of the AH but gives everything more presence.
I've been waiting to break in the promi before doing a side-by-side comparison of the two. I'll report in more detail when I've done the comparison.
Bob
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Bob,
I've got one on order - how long did it take to receive yours?
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Preliminary impressions are that the promi has a wider and deeper soundstage, better detail, resolution and dynamics than the DAC-AH. It retains the tonal character of the AH but gives everything more presence.
I agree with holderlin at this point. After 400 hours (about 2 weeks roughly) you will hear more details and defined music especially the guitar strokes (to my ears) until you bypass the two output capacitors (nichicon muse gold 22uF/100V) with either Mundorf silver oil caps or NOS Vit.Q PIO caps you will like the DAC more (more body).
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It took about 7 weeks to get mine. However, I ordered a usb version and Nicholas wasn't happy with the way it was working so had to re-think how he would deal with the USB version. This was the primary reason for the delay. He's decided, at least for now, to build a separate usb module. I'm awaiting the module.
Bob
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And you have heard this DAC?
I don’t have to listen to the Prometheus DAC to know it’s based on a flawed concept and the circuit design and PCB layout was done by someone who knows nothing about digital logic.
What did you compare it to?
I don’t have to compare the Prometheus DAC to anything to know there are better DAC chips than the TDA1545 and better S/PDIF receivers then the CS8414.
What do you have in your system?
What does my system have to do with the Prometheus DAC?
Have you designed DACs?
Yes. Eight at last count, with one more in development.
Is anyone buying what you have to offer?
No. I don’t offer my designs for sale to the public. Studying, designing, and testing DACs is a hobby and dealing with customers, especially wannabe audiophiles, would take all the fun out of it.
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Thanks for the info jb. If you've been following the Promitheus growth this last year or so you've noticed just how many new products they've released...and they've all been well received from what i can tell. AFAIK the DAC is Promi's only digital offering.
I think its great to post ideas about this or any other product of Nicks...he reads these posts and if you're ideas make sense, he may incorporate them. It doesn't make sense to take a negative tone though, you don't even own the gear dude. i bet you haven't heard a single piece of Promi gear :lol:
Noone should get upset about jb's comments, we're talking about a $400 DAC here, not some $10,000 Class A piece of gear. i'm sure if guys (jb included) wanted to blast the other budget DAC's internals avail it could be done. In this price range i've read many posts of DAC's with hiss, tipped up treble and a strident digi sound. so far the Promi DAC hasn't been grouped in with that bunch, and i think that was Nick's goal. provide something that works for a low, low price.
matt
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I don’t have to compare the Prometheus DAC to anything to know there are better DAC chips than the TDA1545 and better S/PDIF receivers then the CS8414.
jb,
I do not know what are you talking about here. But what I know in the digital world there is a new chip TDA1547 and CS8417 which has been developed and tested. There is a japanese DAC product using these new chip and S/PDIF receiver (to my knowledge).
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I do not know what are you talking about here. But what I know in the digital world there is a new chip TDA1547 and CS8417 which has been developed and tested. There is a japanese DAC product using these new chip and S/PDIF receiver (to my knowledge).
The TDA1547 is a sigma-delta hybrid and not of any use for a NOS DAC. Besides, it is obsolete and discontinued. If you like sigma-delta, there are many better choices that are still in production.
I can’t find any mention of a CS8417.
Fifteen years ago S/PDIF receivers, such as the CS8412, phase-locked the VCO to the bi-phase data stream. Unfortunately, the resulting clock was modulated by the data content. But, that was OK because, back then, parallel DAC chips used FSYNC to trigger the D/A conversion and FSYNC was spectrally pure. All the bit clock had to do was strobe the data bits out of the receiver and into a latch. Later, serial DACs appeared and used the bit clock to trigger the conversion and the spectral contamination in the recovered clock created jitter. Asynchronous reclocking was proposed as a way to decouple the recovered bit clock from the S/PDIF data stream. The idea was that random jitter was preferable to data-correlated jitter. In reality, asynchronous reclocking produces way too much jitter and it is not random but is very predictable resulting in a systematic modulation of the reconstructed audio signal.
[/quote]Noone should get upset about jb's comments, we're talking about a $400 DAC here, not some $10,000 Class A piece of gear. i'm sure if guys (jb included) wanted to blast the other budget DAC's internals avail it could be done. In this price range i've read many posts of DAC's with hiss, tipped up treble and a strident digi sound. so far the Promi DAC hasn't been grouped in with that bunch, and i think that was Nick's goal. provide something that works for a low, low price.
Why does low price always have to mean low quality? Why go to the expense and bother of asynchronous reclocking when you can solve the problem reclocking was supposed to fix by just using a more up-to-date S/PDIF receiver? Modern receivers, such as the CS8415A/16, phase lock on the biphase preambles and the recovered clock is not coupled to the incoming data. I don’t like the CS8416 because is requires dual supplies and includes a digital low-pass filter. The CS8415A uses a single 5v supply and outperforms the CS8414 in every way.
Replacing the CS1814, 100MHz oscillator, and 74AC374 with a CS8415A will reduce cost and improve performance…unless you are in love with the ‘analog-like’ sound produced by asynchronous reclocking. For me the goal is to reproduce the sound of real, live, acoustic music and not the nostalgic duplication of a bygone technology.
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Your knowledge of this subject is just awesome jb, please tell us more...
I made the analog sound comment 'cuz it seems that often DAC reviews mention that quality, or a lack thereof, as some sort of basis. i don't own a DAC but plan to get a pc based ssytem going at some point...so i'm interested.
I for one welcome a strong digi sound as long as its not harsh. being a bass head its tough not to dig it. the HF's of digi have always been a detractor to these young ears though.
budget gear is often lacking, sins of commission rather than omission. its just a fact in this hobby seems like, pitty too. gotta work to find nice gear at low prices.
make us some dope DAC's for $300 bro!!!
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Noone should get upset about jb's comments, we're talking about a $400 DAC here, not some $10,000 Class A piece of gear. i'm sure if guys (jb included) wanted to blast the other budget DAC's internals avail it could be done.
I am not so much concerned about the cost of the product reviewed as much as the overall tone of this thread. JB has a lot to offer - clearly he knows quite a bit about how to put together a decent DAC. I wish I had a strong working knowledge of chips so I could evaluate a product based on its internal components, much less build my own. Goodness knows how many times I have scratched my head when trying to keep up with the many reviewers (professional as well as enthusiest) who identify them in their discissions.
The approach of JB, as well as all of us, could use a little tact. The unilateral condemnation of a person's idea, project, or product is just not very helpful to moving the discussion forward. My questions were aimed at driving that point, to which JB gave adequate responses to. Further, decrying the general populace of this board as "wannabe audiophiles" is especially arrogant. To my perspective, audiophile is merely one who has a passion for reproduced sound - noone here is claiming to be an electrical engineer or sound engineer - we just like music. Just like our tastes in women (and for some, men) everyone knows what they like. We don't all agree, and sometimes we can't explain why we prefer what we prefer. You like a precise, perfectly reproduced sound - don't be so harsh if someone likes theirs a little rough around the edges. I do appreciate how well you have explained the differences in chip hardware. I am only capable of evaluating the difference in how it sounds.
What would be really useful is demonstrating how much better the DAC could be by swapping out the receiver chip and DAC chip in this topology. I think everyone here, (including Nick) would be willing to spend a few bucks more to do this if it really produced a dramatic differnece. I think Nick's approach is based on the "whole" rather than one or two strong parts. His use of transformers appears on the surface to be a very strong foundation for any implementation. I would be very interested why the given chips were selected if other, allegedly superior, chips are readily available.
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After i posted last here i began reading the Altmann DAC thread just a few down from this...seems jb was talkin' trash there too, and blasted the Promi DAC also.
often approach's like jb's are met with friction here :scratch:
I'm kinda interested to know if Promi DAC users are gonna try coupling feet and/or isolated tonewood platforms. And, also what power cords you guys are using.
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After i posted last here i began reading the Altmann DAC thread just a few down from this...seems jb was talkin' trash there too, and blasted the Promi DAC also.
often approach's like jb's are met with friction here :scratch:
I also had researched his other threads before posting my opinion. Again, I don't care one way or the other about the DAC itself. I had to cancel my order as I am getting deployed to Iraq in a few and won't be able to bring it with me. Maybe when I return. :(
The attack came across as if it was aimed personally at Nick and the rest of our community. I feel that kind of behavior is unwarranted and should be put in check.
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I agree completely, the guy has it out for Nick.
Kick some ass over there, watch your back, come back & tell us stories. The Statement DAC will be out by then anyway.
all kidding aside, best of luck.
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I'm kinda interested to know if Promi DAC users are gonna try coupling feet and/or isolated tonewood platforms. And, also what power cords you guys are using.
With my Promitheus DAC I use what Nick included the footers in the package under my Delrin Acetale plateform in between with a 3 inches maple platform. I also use DH cones and Shun Mook discs and footers to try which one is the best match for the DAC and my taste. I have ordered from Nick the power cord that he built only for the DAC (he said AC cord improves the sound of DAC too!).
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very cool Tan, keep us posted on your impressions...
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Audioferret...good luck and stay alert, and dont daydream about gear ya hear?
Stay Safe!!!
jack
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JB,
I for one am very interested in your critiques of digital processing, however a critique is hardly useful without any offering of a solution or at least some guidance.
Since you refuse to offer your own creations to the public, why not suggest an alternative to us lay men? It seems to me that in a DAC, less is more...I'd love to hear which DACs you consider purist in form.
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I agree with Nicolas about the DAC 4 volts ouput with a passive preamp, there is more muscle in the sound, a more dynamic sound than a 2 volts output. For TVC owner, don’t forget to try a higher gain.
By the way, I’m very happy with the Promitheus DAC, even it is not fully broken in yet and I don’t really care about JB’s comments. If he thing he is a shoulder and head above Promitheus or Altman, good for him.
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I for one am very interested in your critiques of digital processing, however a critique is hardly useful without any offering of a solution or at least some guidance.
I thought I did that when I suggested using a better S/PDIF receiver in place of asynchronous reclocking.
Since you refuse to offer your own creations to the public, why not suggest an alternative to us lay men? It seems to me that in a DAC, less is more...I'd love to hear which DACs you consider purist in form.
I agree; less is more. I prefer a quality 20- or 24-bit R2R DAC with no digital filters. The DAC clocks should come from a local oscillator and clock divider using a synchronous counter, not a ripple counter. The oscillator/divider also exports a master clock to slave a CDP or a word clock to sync a PC sound card. Analog output is via passive I/V, anti-image filter, and step-up transformer. No tubes or opamps.
With the digital source synched with the DAC clocks, the data interface, be it S/PDIF, I2S, or other is not critical; it’s just sample data. Compared to 16-bit DAC chips, 20- and 24-bit chips are usually of more recent design, have better linearity, and faster settling time. I know of no commercial DAC that meets my criteria: That’s why I DIY.
There is no reason a DAC similar to what I described should cost much more than the Prometheus. Maintaining the TDA1545, the minimum required circuit changes include a different oscillator frequency, a synchronous counter instead of a latch, and a connector for the exported clock. Slaving a CDP can be a hassle because it involves PCB surgery but connecting a word clock to a sound card is a no-brainer.
For greater flexibility, also replace the CS8414 with a CS8415A and add a jumper to select the source for the clock divider: either the oscillator, for best performance, or MCLK, for use with an unsynced digital source.
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So you prefer upsampling over non-oversampling DAC chips?
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JB,
I'd also like your take on USB v. S/PDIF. I'm quite close to buying the Scott Nixon USB.UFO.JF DAC... www.scott-nixon.com/dac.htm
to be battery powered so as to match my RWA Sig 30.
He does a direct USB to I2S conversion, taking S/PDIF out of the equation entirely. I think he uses the Philips TDA1543 16 bit R2R chip,
and this is one of the purest designed DACs I've found on the market, and a good price to boot.
RE: the PCM 1704 24bit chip, my feeling on upsampling is that the chip is making something out of nothing...mere predictions of what
could have been recorded instead of faithfully reproducing the information it's fed. You don't have an issue with that? To me, many find the
added "detail" and presence of soundstaging to be attractive. I find it at best unnecessary and at worst fatiguing and aggressive.
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So you prefer upsampling over non-oversampling DAC chips?
Where did you get that idea? I said, "I prefer a quality 20- or 24-bit R2R DAC with no digital filters." Please name one 20- or 24-bit R2R upsampling DAC that has no digital filters. Most of the upsampling DACs are delta-sigma, not R2R, and they all have digital filters.
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RE: the PCM 1704 24bit chip, my feeling on upsampling is that the chip is making something out of nothing...mere predictions of what
could have been recorded instead of faithfully reproducing the information it's fed. You don't have an issue with that? To me, many find the
added "detail" and presence of soundstaging to be attractive. I find it at best unnecessary and at worst fatiguing and aggressive.
I suggest you read the datasheet. The PCM1704 is a 24-bit, mono DAC. It does not over- or up-sample. It only supports 8X oversampling when used in conjunction with an 8X over-sampling digital interpolation filter, such as the DF1704.
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RE: the PCM 1704 24bit chip, my feeling on upsampling is that the chip is making something out of nothing...mere predictions of what
could have been recorded instead of faithfully reproducing the information it's fed. You don't have an issue with that? To me, many find the
added "detail" and presence of soundstaging to be attractive. I find it at best unnecessary and at worst fatiguing and aggressive.
I suggest you read the datasheet. The PCM1704 is a 24-bit, mono DAC. It does not over- or up-sample. It only supports 8X oversampling when used in conjunction with an 8X over-sampling digital interpolation filter, such as the DF1704.
Aaah...so my misunderstanding is rooted in the fact that most DACs that use the PCM1704 upsample. Where are the NOS DACs that use this chip? And can I assume that two are needed, one for each channel?
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I'd also like your take on USB v. S/PDIF. I'm quite close to buying the Scott Nixon USB.UFO.JF DAC... www.scott-nixon.com/dac.htm
to be battery powered so as to match my RWA Sig 30.
He does a direct USB to I2S conversion, taking S/PDIF out of the equation entirely. I think he uses the Philips TDA1543 16 bit R2R chip,
and this is one of the purest designed DACs I've found on the market, and a good price to boot.
I’ve already commented on the TDA1543 in the Altmann/LessLoss thread. Some people think it’s the best they’ve heard but even more people think the Bose Wave Radio/CD is the best they’ve heard. I guess that makes the Bose better by popular acclaim.
There is nothing wrong with S/PDIF if you use a good receiver or, better yet, get only the data from S/PDIF and the clocks from a local oscillator and clock divider. On the other hand, USB is probably the worst digital interface for high quality music. If you don’t know how it works, go to usb.org, download and read the specs. The last time I looked the appropriate documents were called usb20.pdf and audio10.pdf. There is also some good information at microsoft.com called USB_Audio_and_Windows.doc but chances are its been updated and renamed for Vista. The truth is out there is you care to look for it...or you can believe the snake oil salesmen who will tell you anything in order to get your money.
Here are some highlights. The data is packetized with each packet holding 1 millisecond worth of samples. With a 44.1K sample rate, the sample period is not an integer divisor of 1ms and some packets will have more samples than others. That’s OK because the USB jitter spec is +/- one sample! In case of a transmission error, the entire packet is discarded and the DAC outputs 1 millisecond of silence. There is no retransmission. Compare that to S/PDIF where error checking is done on each sample. In case of an error, the S/PDIF receiver repeats the last good sample and raises an error flag. In response to the error flag, it’s up to the DAC to accept the duplicated sample or do something else, such as interpolate through the error. Most DACs do the former, which in the case of upsampling results in interpolation anyway. In any event, one repeated sample is considerably less noticeable than 1 ms of silence.
Where are the NOS DACs that use this chip?
All of my DACs use NOS PCM1704 chips. Highend DACs don't because upsampling and delta-sigma is in vogue. Budget and DIY DACs don't because the chips are expensive and hard to find. You also need two of them along with some glue logic and knowledge of digital circuits to make them work. The latter two items are not needed when the chips are used with a DF1704.
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Hi acd483 and jb
Caveat I just saw the new post so some of my questions are now moot, sorry. :duh:
Thanks jb for more feedback so we might have a little better handel on this stuff. :D
to acd483 I have a Monarchy NM24 DAC with 2 1704s and it does not up-sample.
:scratch: I am certainly no expert by a very long shot but I thought I clearly understood upsample is not oversample. It seems many people assume they are the same. I could be wrong but I believe the goals of the 2 are different.
upsampling I think in the most simplistic sense is designed to make a 16/44 source sound similar to a 24/96 (192) source in the most ideal sense.
oversampling is simply a way of handeling the source be it 16/44 or 24/96 (if the chip supports 24/96) and all the math that goes with it filtering and so forth. This process in itself is not necessarliy more damaging to the signal than the NOS approach. and a lot of its final outcome has everything to do with the implimentation of the individual pieces in the design.
I have read some of the papers on the Delta Sigmas and this stuff but they quickly leave my small mathmatical brain in the dust.
Seems the movement towards the NOS DACs is purist in idea but is not necessarily the holy grail of design (if any of the ideas are or math is)? Or it simply has not been really well implimented yet due to its being relatively new (I beleve it is NEO in the sense its a further investigaion of an earlier digital processing idea and is being openned again to see what the designers may have overlooked the first time).
Anyway thanks jb for attempting to get us to understand some of this stuff, if you have the patience most of could probably benifit greatly from the most simplistic explaination with possible simple analogies- ie:
1-single comes in
2- 1st it goes here. (with this goal)
3- then it goes here (with that goal)
but in a NOS design then it goes there
with a oversample design it goes here
that type of thing.
just a thought, many of us love our music and are thrilled to have just the most basic layman's understanding of how this works. If you have already done this sorry for asking again for it to be really dummied down. :duh:
This is answered in the above post. I am curious if a PCM 1704 DAC chip only oversamples when it is used with a filter such as the DF1704 can the chip it self be used in a NOS design. Or does it only function when used with a digital filter.
What is Glue Logic?
You must be having a blast avoiding many of the pitfalls of so much of the commerically designed DACs. :D It certainly makes you an audiophile in the puruist sense of the word = (I am not putting up with this I will make my own!). :lol: excellent
thanks in advance for your insights
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I'd also like your take on USB v. S/PDIF. I'm quite close to buying the Scott Nixon USB.UFO.JF DAC... www.scott-nixon.com/dac.htm
to be battery powered so as to match my RWA Sig 30.
He does a direct USB to I2S conversion, taking S/PDIF out of the equation entirely. I think he uses the Philips TDA1543 16 bit R2R chip,
and this is one of the purest designed DACs I've found on the market, and a good price to boot.
I’ve already commented on the TDA1543 in the Altmann/LessLoss thread. Some people think it’s the best they’ve heard but even more people think the Bose Wave Radio/CD is the best they’ve heard. I guess that makes the Bose better by popular acclaim.
There is nothing wrong with S/PDIF if you use a good receiver or, better yet, get only the data from S/PDIF and the clocks from a local oscillator and clock divider. On the other hand, USB is probably the worst digital interface for high quality music. If you don’t know how it works, go to usb.org, download and read the specs. The last time I looked the appropriate documents were called usb20.pdf and audio10.pdf. There is also some good information at microsoft.com called USB_Audio_and_Windows.doc but chances are its been updated and renamed for Vista. The truth is out there is you care to look for it...or you can believe the snake oil salesmen who will tell you anything in order to get your money.
Here are some highlights. The data is packetized with each packet holding 1 millisecond worth of samples. With a 44.1K sample rate, the sample period is not an integer divisor of 1ms and some packets will have more samples than others. That’s OK because the USB jitter spec is +/- one sample! In case of a transmission error, the entire packet is discarded and the DAC outputs 1 millisecond of silence. There is no retransmission. Compare that to S/PDIF where error checking is done on each sample. In case of an error, the S/PDIF receiver repeats the last good sample and raises an error flag. In response to the error flag, it’s up to the DAC to accept the duplicated sample or do something else, such as interpolate through the error. Most DACs do the former, which in the case of upsampling results in interpolation anyway. In any event, one repeated sample is considerably less noticeable than 1 ms of silence.
Where are the NOS DACs that use this chip?
All of my DACs use NOS PCM1704 chips. Highend DACs don't because upsampling and delta-sigma is in vogue. Budget and DIY DACs don't because the chips are expensive and hard to find. You also need two of them along with some glue logic and knowledge of digital circuits to make them work. The latter two items are not needed when the chips are used with a DF1704.
It's my understanding that transmission errors in USB transmission are extremely rare. I'm not sure how much attention you've paid to USB chips, but the latest do a much better job dealing with data transmission/clocking than the original ones.
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It's my understanding that transmission errors in USB are extremely rare.
No more rare than S/PDIF errors. Read the damn specs!
Earlier today I read a post on another audio forum from an audiophile who had a very high quality USB-based PC audio system but he was bothered by occasional random clicks, maybe one or two a day. He tweaked and changed everything in his system but clicks would not go away until he changed his interface from USB to S/PDIF.
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Haha, I read your specs...from 9 years ago. Hmmm...wonder if USB technology has improved since then...
And anyway, I wasn't comparing S/PDIF to USB in terms of errors made. We're not talking relativity here. In proper USB integration, it's an error every MONTH or so, not many times a day. But let's be honest, old USB interfaces are junk. USB interfaces that convert to S/PDIF first, rather than directly to I2S are junk. PC computers are junk. You haven't given a clue as to his setup. The truth is, his system may be so flawed, that while S/PDIF removed the clicking...which is a result of the DAC and the computer not talking to each other correctly, it may not have improved the SOUND at all.
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Haha, I read your specs...from 9 years ago. Hmmm...wonder if USB technology has improved since then...
And anyway, I wasn't comparing S/PDIF to USB in terms of errors made. We're not talking relativity here. In proper USB integration, it's an error every MONTH or so, not many times a day. But let's be honest, old USB interfaces are junk. USB interfaces that convert to S/PDIF first, rather than directly to I2S are junk. PC computers are junk. You haven't given a clue as to his setup. The truth is, his system may be so flawed, that while S/PDIF removed the clicking...which is a result of the DAC and the computer not talking to each other correctly, it may not have improved the SOUND at all.
I'd also like your take on USB v. S/PDIF.
You asked for my take and I told you. If you were already convinced that USB, with its +/- one sample jitter and 1 ms dropout in case of error is superior, why did you ask?
When it comes to clock quality, there is little difference between S/PDIF and USB when each is implemented properly. Both interfaces use a VCO that is phase-locked to the incoming signal. S/PDIF locks on the biphase preambles, which are timed by the word clock of the digital source. USB locks on the 1ms ticks from the host and adjusts the bit/word clocks to output all the samples it received in the last packet over the next millisecond interval. Neither VCO-derived clock is as good as the output of a crystal oscillator and clock divider clocking the DAC chip directly.
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Hi guys, just received my Promitheus Dac (USB with all silver upgrades) last week and have been burning it in since (about 100 hours total). It now sounds a little silkier than when it first arrived but quite frankly it was fantastic from the beginning (with just a little harshness to remind you it was a new component). Wow ! What a sound !
This was my first experience with a NOS dac and I actually like it far more (from memory) than the Vacuum State Electronics modified Sony SACD player I used to own (and which has always received rave reviews). The Promitheus is far more musical. Though the modified SACD was more transparent and had a better soundstage (and was the only CD player/SACD player to use a low pass filter only, and to entirely bypass the DAC altogether!), it always seemed a little too sterile and cautious/civilised to me (and this was with Parallel Single-Ended 300b monoblocks into Lowthers). It didn't get up and boogy or get down and dirty (dirty in a fun sense, not a "Christina Aguillera" sense ... though Christina dirty might actually be fun too) !
This DAC is the antithesis of all that - It sounds a little like a very, very relaxed Naim component (I still have a CD 3 and Nait amplifier I love very much) but with MUCH greater transparency and bass. That means it is dynamic, emotion bearing, crisp when required, soft when appropriate and always amazingly "coherent". In fact, whilst I have enjoyed the levels of detail, natural warmth (and natural harshness when the recording is harsh - this isn't a "cloying" syrypy component by any stretch of the imagination), phenomenal bass depth and agility, it is this intoxicating cohesiveness which I find it's most amazing attribute. The music hangs together beautifully, makes musical sense, the bass isn't slow, the treble isn't fast and everything is "cut from the same cloth" in the same way that good analogue is. Music is joyful and vibrant, but as I said it is relaxed - this gives an interesting juxtaposition of a component which is cohesive and has great PRAT, but which doesn't subjectively sound "fast" (like the Naims do ... I know it's a colouration, but oh what a glorious colouration). It sounds laid-back, and composed (not in a boring way), but still has plenty of energy and verve. The sound is magnificent, but the musicality is even better according to my tastes. I now wish I had ordered the upgraded caps to see just how good this thing gets
Like Bob, I have not yet received my USB module (which Nic has taked out of the main DAC casing due to noise issues), so bear in mind I have it sub-optimally set up at the moment (borrowed a friends Trends USB convertor and using a Radioshack crappy interconnect as digital coax - bad I know !). I am actually happy with this as it shows Nic's perfectionist streak and integrity ... I know I will get a USB convertor when the USB convertor is good enough to go with the DAC and not sully its sound. Oh, by the way, Nic is adding a pulse transformer - at his own expense - to the USB convertor so that he is happy with the sound !! Now THAT'S integrity. Will post further review with more breaking in when the USB convertor arrives, but at this stage I feel I have snared an incredible bargain - and that feels good.
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brynaus,
Great review. It is happened exactly like my Promi DAC but I use RCA/BNC. I also bypassed the Panasonic output capacitors with Vitamin Q PIO. Now the DAC is going to another higher level of sound. :thumb:
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Hi Tanchiro,
It was partly your reviews which led to me purchasing this DAC, so thank you so much for your pioneering efforts ! It looks like I am going to have to learn how to solder very soon :duh:
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It looks like I am going to have to learn how to solder very soon
Brynaus,
If you would like to start soldering I suggest to buy a good solder station and quality lead from Vampire. Here are the links:
http://www.circuitspecialists.com/prod.itml/icOid/7307
http://www.soniccraft.com/products/connections/solder/vampire.htm
If you need help just PM me. Good luck
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Seems the movement towards the NOS DACs is purist in idea but is not necessarily the holy grail of design (if any of the ideas are or math is)? Or it simply has not been really well implimented yet due to its being relatively new (I beleve it is NEO in the sense its a further investigaion of an earlier digital processing idea and is being openned again to see what the designers may have overlooked the first time).
Anyway thanks jb for attempting to get us to understand some of this stuff, if you have the patience most of could probably benifit greatly from the most simplistic explaination with possible simple analogies:
There is confusion because there is no universally agreed to definition of the terms oversampling and upsampling. Here are selected highlights and a simplified overview of the evolution of CD playback.
The standards for CDs represent the absolute minimum for recording sound, not music. The samples are too small and the sample rate is too low. According to sampling theory, the low sample rate required a very steep, ‘brick wall,’ anti-image filter, which contributed to the bad sound of the first generation DACs.
At the time, microprocessors were too slow to be able to manipulate the sample data in real time and DAC designers did what they could to increase the clock rate of the DAC to reduce the severe requirements of the anti-image filter. This brand new idea was called 2X over-sampling. It involved doubling the clock rate and inserting a null sample in between each recorded sample. Today, that technique is sometimes called decimation. The problem is decimation halves the energy content of the signal and adds noise. I believe preserving the energy content is essential to accurately reconstruct music.
The next attempt, called 4X oversampling, involved using 4 DACs that operate on successive quarters of the sample period. The outputs of the DACs are summed. The sample rate is quadrupled and the effective sample size is increased by two bits. However, instead of a vertical step between recorded samples, as there would be with no oversampling, there is a diagonal line between the two points. Instead of a square wave, the DAC outputs more of a triangular wave. In terms of energy content, a triangular wave does not approximate the energy in a sine wave as well as square wave does. Today we call it linear analog interpolation.
When microprocessors were fast enough to manipulate the sample data in real-time we got 8X oversampling and the digital filter. The technique, more properly called digital interpolation, attempts to recreate the shape of the signal in between each pair of samples from the original recording. To do so, a large number of samples preceding and following the sample period being interpolated are examined to determine the shape of the signal through the period in question. The accuracy of the interpolation depends on the accuracy of the samples and a similar shape of the signal leading up to and following the interpolated period. The effective sample size is increased by three bits.
So far, only the added samples are the result of calculations, the original samples are preserved, and the sample rate is increased by an integer power of two. The next generation of digital interpolation used non-integer sample-rate multipliers and was called UPsampling to differentiate it from all previous incarnations of OVERsampling. The only thing that is different is the non-integer multiplier and the fact that now every sample is the result of a calculation. The output is essentially a digitally synthesized version of the original recording.
Asynchronous sample rate conversion is a variation of upsampling. Instead of a fixed sample rate multiplier applied to the input sample clock, the sample rate multiplier is determined by continuously computing the difference between the input sample clock and another reference or output sample clock.
In my opinion, the evolution of CD playback has gone from bad to worse. Although upsampling improves the quality of steady-state sine waves, it doesn’t improve the quality of recorded music. That conjecture is proven by the renaissance of NOS DACs. If the newest generation of CD playback technology were as good as the promoters say it is, there would be no desire for music lovers to want to revisit the past.
Unfortunately, in their zeal to reject everything that was wrong with prior attempts to reproduce music, NOS proponents have thrown the baby out with the bath water. Yes, the brick-wall filter is bad and so is the digital filter, but a proper reconstruction filter, also called an anti-image filter, is an absolute requirement for any digital to analog converter. While 8X upsampling and extending the 16-bit sample to 24-bits with what is essentially noise doesn’t enhance the music, 24-bit DACs are superior to 16-bit DACs whether or not you use all the bits. Also, there’s nothing wrong with upping the sample rate provided you preserve the energy content of every sample.
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What's the story with 128X (or 256X) oversampling - anything gained from this? (Thinking of the AK4393 (http://www.asahi-kasei.co.jp/akm/en/product/ak4393/ak4393_f02e.pdf) etc DAC chips here...)
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Thanks Tanchiro,
After the DAC has had 400 hours break-in and is fully stabilised, I will order the caps etc. from Nicholas and contact you directly - I will close my eyes, whisper a prayer and try to ignore the likely smell of searing flesh !!
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@jb
what are your thoughts on this:
http://www.vdac.co.uk/vdac4.html
25bit 210k upsampling
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In terms of energy content, a triangular wave does not approximate the energy in a sine wave as well as square wave does.
What on earth is this supposed to mean? :duh:
I just ran into this train wreck. Does anyone other than me think that perhaps the little sidetrack by jb should be moved to another thread?
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JohnR,
You should add one more forum in AC for Pro DAC or Studio Pro. etc... To be honest it is good to learn from everyone' experiences or DIY's experiences but too much of theories of audio-engineering I have never interested. :nono: :stupid:
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What's the story with 128X (or 256X) oversampling - anything gained from this?
Let me ask you: What could possibly be gained by oversampling Redbook to delta-sigma? According to sampling theory, you can reduce the sample width by one bit for each doubling of the sample rate and not lose information. You have to oversample 128X when converting to delta-sigma in order to simply preserve the basic audio quality of 44.1K/16-bit CD audio and in the process you suffer the consequences of oversampling and get the dynamics of a 7-bit DAC.
For those of you in Rio Linda, a delta-sigma DAC steps one bit each sample period. With 128X oversampling, a delta-sigma DAC can slew through a maximum of 128 points (2^7) in the same time a 44.1k/16-bit DAC can slew through 65536 points (2^16).
256X delta-sigma is theoretically equivalent to 2X oversampled Redbook PCM. The audio industry loves delta-sigma because the chips are cheap. Audiophiles love delta-sigma because they believe everything the audio industry tells them.
what are your thoughts on this: 25bit 210k upsampling
Why do any of you care what I think about this or that DAC? Use your ears and brain and choose the DAC that suits you.
In terms of energy content, a triangular wave does not approximate the energy in a sine wave as well as square wave does.
What on earth is this supposed to mean? :duh:
The energy content of a signal is the total area under the curve. :duh:
The technical ignorance on display in this forum is staggering. Doesn’t anyone know anything beyond what the advertisers tell you?
I just ran into this train wreck. Does anyone other than me think that perhaps the little sidetrack by jb should be moved to another thread?
First I was criticized for continuing my critique of the Altmann and LessLoss DACs in new thread. Now I am criticized for sidetracking this thread with my critique of asynchronous reclocking, as it applies to the Prometheus DAC, and graciously answering questions. I can’t win.
John, if you don’t like what I have to say, you have the power to move or delete my posts. Like the other audio forum operators, you like happy talk that promotes the audio industry, in general, and your sponsors, in particular. You certainly don’t want anyone pointing out the emperor has no clothes. I’ll make it easy for you by not posting here again.
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I’ll make it easy for you by not posting here again.
That will make it easier for me. Thank you.
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I’ll make it easy for you by not posting here again.
That will make it easier for me. Thank you.
Heavy handed censorship is always easier than attempting to understand some of the technical issues involved, isn't it John. Just exactly what is so terrible about a technical discussion of DAC's?
d.b.
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It's not the discussion, Dan, it's the sneering and insults. Just like you, in fact. People who are genuinely knowledgeable generally don't, in my experience, feel the need to insult others as a way to bolster their own authority or knowledge. I don't welcome it here, and absolutely, my life will be easier without it.
So I guess this is where we're going, Dan. I work hard to make this site work, you don't. I've asked you time and time and time again to either make a positive contribution, or stay away. Your cheap shot about censorship and the like... well, what can I say. My life would be easier if you weren't in it, too, Dan. So how about it?
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It's not the discussion, Dan, it's the sneering and insults. Just like you, in fact. People who are genuinely knowledgeable generally don't, in my experience, feel the need to insult others as a way to bolster their own authority or knowledge. I don't welcome it here, and absolutely, my life will be easier without it.
So I guess this is where we're going, Dan. I work hard to make this site work, you don't. I've asked you time and time and time again to either make a positive contribution, or stay away. Your cheap shot about censorship and the like... well, what can I say. My life would be easier if you weren't in it, too, Dan. So how about it?
jb has presented technical issues about DAC's that are well known to those of us who are either involved or have been involved with DAC's. From what I have reviewed in this thread jb has made his case without being "snotty", unless of course you consider the presentation of well known technical issues to be "snotty'
Once again you have not addressed my question: Just what exactly is so terrible about a technical discussion of DAC's?
And BTW: I have also worked hard to bring some amount of technical education to this forum, and no I don't get paid for that. I also work hard to write articles for Audioholics that hopefully inform readers of the technical issues that audiophiles face and the monetary reward for that is a check to Habitat for Humanity.
d.b.
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You have selective blindness, Dan. Here are a few quote I found in a few seconds of looking
The technical ignorance on display in this forum is staggering.
dealing with customers, especially wannabe audiophiles, would take all the fun out of it.
If all you golden ears think the Prometheus DAC is the best you have every heard. What can I say? Ignorance is bliss. Enjoy.
I'm grateful for his invitation to leave, as (didn't I already say this?) I've had a gut-ful of shit like this from people such as, well, you. I only wish you had kept to yours.
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Well it certainly appears that you do not wish to answer my question. I can only conclude at this point that you view any technical discussion of DAC's to be of no service or interest to members of audio circle.
d.b.
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I never said there was anything terrible about a technical discussion of DACs, I asked if anyone else thought the discussion should be split out of this thread. I do find some of his explanations (what I read) a little odd.... and I have taught a basic class in Signal Theory so I'm not a complete ignoramous. I supposed I could have asked my question a little more tactfully, I guess the tone was set in my mind by the earlier statements he made. My bad :duh:
Anyway Dan, I'm afraid the time has come. You made your intention to cause trouble clear from the beginning of AC, when you declined a circle because you thought that if you had one we wouldn't allow you to attack cable manufacturers. You've wasted plenty of Admin time of the years, and you're the only person who's ever had two time-outs, I believe. And your re-entry to the board after our last discussion about your positive contribution (or lack of) is to come out accusing me of censorship. We've been through a lot of changes this year, Dan, and they haven't been easy. I really have no energy to deal with nonsense from you. Please have your last retort now and then we will part ways. Thank you.
JohnR
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Dan - the world is not full of engineers and technical types....and while any forum on audio or high fidelity may attract more than it's slice of life of engineers and the like, that doesn't change the general population's make-up. Indeed, many of the things jb has cited is well over the head of the average music enthusiast. Including me.
For that reason there is an area called The Lab...where folks like you (and 'jb') can congregate and get all hot and lathered up over 'scope results and the like. Which is where you normally participate at AC....not here in the enthusiast area called 'Multi-Channel'
The times when the techies enter a general enthusiast area...we (majority) non-technical types shouldn't be made to feel foolish for our lack of engineering skills. Consistently by some, including you, we're scalded for shit that you take for granted. If you can't participate nicely with ALL the others, then just hang with your fellow geeks in The Lab.
Better yet, as you've clearly worn our your welcome at AC after years of pounding the same insipid points, go hang out elsewhere on the net on sites for technical and DIY'ers only. You must have some innate need to create strife and laud your technical merits over those who cannot grasp at it. And yet you continue at it, year after year, denigrating too many around you.
I'm not about to apologize for being a Marketing major or my choices in career to you or anyone else. I'm here for the same reason as most...we enjoy re-producing music as it's heard live in our homes and hope to better approximate it over time. Everyone hears that differently and approaches it with their own set of insights and rules. For many, it's just morphed into a place where you can share laughs, stories, grief about life in general. I, and we, don't want to be told we are 'wannabe audiophiles' because we lack technical prowess, or 'ignorant'. That's just simply not nice, not fair to say and doesn't promote community at AudioCircle.
Your endorsement of such talk speaks volumes about how FUBAR'ed you really are. Go away - you have promised as such, but seem to gravitate back each time. It seems your need to denigrate and show some purported technical prowess is endless and incessant - go take care of that need to indulge in it somewhere else.
Go away, go away, go away - you are irritating and insulting and I and others are sick of hearing you. Who knows, you may be an allright guy outside of this forum...but the persona you take on here is consistently wanting for humanity, understanding and patience for the majority. You are the CircleJerk personified. You've worn out your welcome so many times it's just annoying now. Ta-ta.
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I don’t think this thread would have degenerated into such unpleasantness if jb had expressed his technical criticisms in a different and more positive way, there is of course nothing wrong in sharing your opinions about any technical issues regarding DACs or anything else for that matter, however if it looks to others like they are mainly negative comments about the performance of the Promitheus DAC on a thread obviously started by people who have only just ordered it, or who already own one and are evidently enjoying their purchase your negative criticisms could be viewed by some as unwelcome.
As far as I know nobody likes a smart ass who comes up to you just after you’ve just bought something and says “that’s a load of crap I know of a much better one but I’m not going to tell you about it!”
It would perhaps have been better to start a new thread about this issue rather than choosing an already established one started by people who like Nick’s product.
Jb said he believes he has a better solution in his own DIY DAC than any of the current “in vogue” (as he put it) filtered non-os or up-sampling dacs commercially available, however he is unwilling to share his ‘less flawed’ design with any one else.
If jb really does have a superior DAC design then why not share it at somewhere like diyaudio.com? I fail to see why doing so would take the fun out of anything, sure you will get some criticism from people but if you’re willing to dish it out you must be willing to take some yourself.
Ultimately jb’s design would speak for itself with its vastly superior sound quality that crushes the competition.
BTW I don’t own a Promitheus DAC nor have I just ordered one :lol:
If ignorance is bliss as jb said then I’m really glad all you Prometheus owners are happy :D (edit) eeerm I didn't mean any Promitheus owner was ignorant BTW if so I must be too as I own one of nicks TVC's :lol:
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Well Hell....I do believe our new friend jb could have been a wee bit more tactful in his presentation. I do believe this was the beginning of the end of this thread, a few peoples tempters, and possibly Dan B himself. I enjoy hanging here and learning form you guys, but it's a shame in out little niche hobby that the few of us that belong can't calm down a notch or two. A few things have been said by numerous individuals that either didn't need to be said at all, or in the very least, could have been said more gently/tackfully. I see tempers, ego's, and pissing contests. None of this is necessary.
Please to all: Think before you post.
Your Father taught you that....Didn't he?
Bob
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If this is a world of competition IMO you have gut to present your own good audio products to share with others (average people who know how to listen musics not really wanabe audiophiles) then I would welcome to give a try.
I am not affiliate to Promitheus Audio and just want to express my thought of owning TVC and now DAC which I already shared with my friends in the neighborhood and in this circle. They are appreciated to have a good share they have never found to be satisfied before like Promitheus TVC. And I think this is the purpose of Audio Circle.
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I’ll make it easy for you by not posting here again.
That will make it easier for me. Thank you.
Heavy handed censorship is always easier than attempting to understand some of the technical issues involved, isn't it John. Just exactly what is so terrible about a technical discussion of DAC's?
d.b.
bad manners and a lack of social skills. one romy the cat is enough for the whole audio world, unless you believe that every segment (horns, DACs, SETs, wires) should have one.
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Has anyone else seen the movie "Marathon Man". Just imagine Laurence Olivier leaning over you ... "Is it safe yet" ? :roll:
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I can say that on the board and in our PMs, I learned quite a bit from jb, and hope that he continues to contribute to the discussion. I agree, it's useless to interject in thread after thread about the issues associated with a given product without offering an alternative. I gave jb the opportunity to step up, get his DAC out there and listened to, for if he is that confident in his product, he should want to show it off. I think all of us potential consumers are fair enough to judge by our ears and if one DAC is better than the next, we'll promote it.
This industry is about innovation, not deception. If you've got a better product, build it, sell it, get it reviewed and take pride.
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This industry is about innovation, not deception. If you've got a better product, build it, sell it, get it reviewed and take pride.
Good point acd483. Exactly what I have had in mind. But in the real life, a few of people have a gut to show off their innovations especially in audio society.
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So...about the DAC.... :wink:
Let's get the discussion back on topic (which, I believe was the point if JohnRs interjection - not censorship)
I think the relative cost/capabilities of the DACs should receive more discussion. Keep in mind that the obvious expense of actually purchasing and comparing all of these DACs is prohibitive.
Can anyone establish a ranking (or other relative comparison) of this DAC and others in its class? (class meaning among DACs of similar cost or among DACs with similar capabilities) For example, is it better or worse then a $600.00 VDA2 from CI audio? The $300.00 miniDAC from headroom? If I purchased a $1,200.00 Benchmark DAC-1 USB, what am I getting for the additional $800.00 that makes it worth it? IF I had $1,200.00 to spend, what could I get in additon to the Promi DAC that makes it worth it?
Example: Promi DAC ($340.00), USB module ($40) and TVC ($320.00) is a $700 combo that has similar capabilities to the Benchmark. (prices are estimates, of course) If I were to choose one or the other, how would they compare? WHich is the better value? Which looks nicer? Is more portable? More accurate? Sounds better?
This is the direction I hope to see this thread move. Let's get away from the idiosyncratic discussion of the merit of people's character - that is not getting us anywhere. The subject of the thread is the Promi DAC, let's talk about that.
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I'd love to hear it compared to the Altmann DAC - both use similar DAC's and are NOS. Has anyone done this comparison yet ?
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I'd love to hear it compared to the Altmann DAC - both use similar DAC's and are NOS. Has anyone done this comparison yet ?
I wonder if enough people have purchased the Promitheus DAC thus far, to make many comparisons yet. :dunno:
P.S. I personally will miss the posts of jb and Dan, they were some of the most informative posts I've ever seen on the forum. I can see how some members may have become offended by the occasionally frustrated tone of some of those posts, but I personally thought the tone was in response to audio manufacturers taking advantage of consumers - and not necessarily directed at the 'non-engineering type' consumers themselves. It can be good to have some people "mix it up" a bit around these forums, helps to keep things in perspective in my opinion. I'm also sure it must be hard work to run and maintain these forums, and to make such judgement calls too. :|
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I'd love to hear it compared to the Altmann DAC - both use similar DAC's and are NOS. Has anyone done this comparison yet ?
there is a very very few people who moved on from altmann.
most of its users stay for sonic reasons while among those who move on, a majority is due to logistic issues (open PCB, car battery).
a real problem with altmann is that you don't want to hear any other DAC after it.
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a real problem with altmann is that you don't want to hear any other DAC after it.
If this statement is realistic how do or did audiophiles (including wannabe audiophiles) and/or audio lovers know (for sure!) Altmann Attraction DAC will be outbest other NOS DAC or over-and upsampling DACs even though there are a lot of best DACs outhere (maybe you have not even known yet!!!). :wink:
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I know quite a few Altmann user, but none of them is interested to know if there is anything "better" out there...
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a real problem with altmann is that you don't want to hear any other DAC after it.
So true but, I don't consider it a problem! Okay, it is a problem because I don't own one :(
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Okay, it is a problem because I don't own one
Also because it does not fit to your budget!!! :bawl:
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I am all for people knowing what they are talking about before they decide to talk but JB's posts were technical nonsense.
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I am all for people knowing what they are talking about before they decide to talk but JB's posts were technical nonsense.
I guess you can say that without fear of rebuttal from jb as he has not logged in since 9 minutes after his last post 3 days ago.
I would be interested in seeing one example of the nonsense you refer to.
I'm no expert on digital theory, but nothing he said conflicted with what little I know, and I was looking forward to being enlightened.
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I am all for people knowing what they are talking about before they decide to talk but JB's posts were technical nonsense.
Elaborate.
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As for the Altmann, if I paid that much for it, I'd be holding on too.
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As for the Altmann, if I paid that much for it, I'd be holding on too.
it's probably the best sound per price available on the market. bargain at 750E or whatever you paid.
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Hi Tanchiro,
I saw you are using Lavry Black DA10 DACs as well, how did it compare with Promi?
I am still waiting for my Promi Dac and Apollo pre.... Dunno why it take such a long time for the engraving/chassis :scratch:
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I am all for people knowing what they are talking about before they decide to talk but JB's posts were technical nonsense.
I guess you can say that without fear of rebuttal from jb as he has not logged in since 9 minutes after his last post 3 days ago.
I would be interested in seeing one example of the nonsense you refer to.
I'm no expert on digital theory, but nothing he said conflicted with what little I know, and I was looking forward to being enlightened.
LOL
:surrender:
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I am all for people knowing what they are talking about before they decide to talk but JB's posts were technical nonsense.
Elaborate.
Alrighty then.
The standards for CDs represent the absolute minimum for recording sound, not music. The samples are too small and the sample rate is too low. According to sampling theory, the low sample rate required a very steep, ‘brick wall,’ anti-image filter, which contributed to the bad sound of the first generation DACs.
B.S.
44,100 samples per second and 16 bits resolution yeilds a bandwidth of 22,050hz and noise level of -96db.
It is a mathematical fact that any error resulting from encoding at 44.1k and 16 bits must be either above 22.05khz or below -96db, Period!
This leaves plenty of room for full bandwidth music on a blank (silent) canvas.
You could go more but it is not necessary (even for audiophiles).
Your hearing might exceed the bandwidth of the 44khz sampling system which will be less than the nyquist frequency to limit the ringing of the ant-alias filter and could in theory exceed the dynamic range of the 16 bit system which would require a very high output system and very quiet listening environment.
This is simply a trivial fact and should not get in the way of understanding that 44khz and 16 bits has the potential to encode incredibly detailed music.
Fortunately the anti-alias filter is at the top of the audio range where your hearing is barely there so don't get too hung up on this detail.
A filter with rounder knee can also be used if you like.
At the time, microprocessors were too slow to be able to manipulate the sample data in real time and DAC designers did what they could to increase the clock rate of the DAC to reduce the severe requirements of the anti-image filter. This brand new idea was called 2X over-sampling. It involved doubling the clock rate and inserting a null sample in between each recorded sample. Today, that technique is sometimes called decimation. The problem is decimation halves the energy content of the signal and adds noise. I believe preserving the energy content is essential to accurately reconstruct music.
The added noise is above the passband and there is no consequence to the resulting level being -6db (or even -60db) unless your filter lacks the mathematical precision for accurate calculation of the signal.
The next attempt, called 4X oversampling, involved using 4 DACs that operate on successive quarters of the sample period. The outputs of the DACs are summed. The sample rate is quadrupled and the effective sample size is increased by two bits. However, instead of a vertical step between recorded samples, as there would be with no oversampling, there is a diagonal line between the two points. Instead of a square wave, the DAC outputs more of a triangular wave. In terms of energy content, a triangular wave does not approximate the energy in a sine wave as well as square wave does. Today we call it linear analog interpolation.
Actually a trangle wave approxamates a sine wave much better than a square wave.
The amplitude of a square waves harmonics is equal to the reciprocal of the harmonic number while the amplitude of a triangle waves harmonics is equal to the reciprocal of the harmonic number squared.
The triangle wave is much more pure.
This is not how four times oversampling systems were implemented although I'm shure there have been some implemented in this manner as it is a good idea that does not require a digital filter as the multiple DAC's diffused timing will cause high frequencies to cancel creating a filter.
Also since no formal digital filter is employed there are no samples generated with values between the steps of the 16 bit system which would require higher resolution DAC's and/or redithering to properly decode.
This approach could be further refined by using more DAC's with giving finer diffusion and adjusting the gain of each DAC in the sequence so that their resultant response mimics that of a desirable filter function (the gain of each of the DAC's in the timed series would be adjusted acording to the impulse response of a target LP filter).
Having all of the DAC's in the series at the same gain also works but the resultant filter has some ripple and the slope is limited, having more DAC's and tuning their gains would allow for even more refined filter responses (If you were trying to build a high-end DAC with early 80's technology this would be the way to do it).
Standard oversampling systems (2x, 4x, 8x....) oversample by inserting null samples between the existing samples then use a digital filter and then a DAC running at the oversampling sample rate.
Employing multiple DAC's can increase the effective number of bits (S/N) of a DAC system either by oversampling and dithering or by feeding the data to them in such a way that more steps are available or by oversampling and noise shaping however the above described multiple DAC method does not give an effective increase in the number of bits.
When microprocessors were fast enough to manipulate the sample data in real-time we got 8X oversampling and the digital filter. The technique, more properly called digital interpolation, attempts to recreate the shape of the signal in between each pair of samples from the original recording. To do so, a large number of samples preceding and following the sample period being interpolated are examined to determine the shape of the signal through the period in question. The accuracy of the interpolation depends on the accuracy of the samples and a similar shape of the signal leading up to and following the interpolated period. The effective sample size is increased by three bits.
Microprocessors were only used in ultra expesive models when they became available.
Digital filters are what was used since the first 2x oversampling DAC's were employed not introduced for the first time with 8x oversampling.
A digital filter is not a microprocessor but an aplication specific IC which is setup to perform a single task.
The effective resolution is increased 1.5 bits not 3.
So far, only the added samples are the result of calculations, the original samples are preserved, and the sample rate is increased by an integer power of two. The next generation of digital interpolation used non-integer sample-rate multipliers and was called UPsampling to differentiate it from all previous incarnations of OVERsampling. The only thing that is different is the non-integer multiplier and the fact that now every sample is the result of a calculation. The output is essentially a digitally synthesized version of the original recording.
Asynchronous sample rate conversion is a variation of upsampling. Instead of a fixed sample rate multiplier applied to the input sample clock, the sample rate multiplier is determined by continuously computing the difference between the input sample clock and another reference or output sample clock.
In my opinion, the evolution of CD playback has gone from bad to worse. Although upsampling improves the quality of steady-state sine waves, it doesn’t improve the quality of recorded music. That conjecture is proven by the renaissance of NOS DACs. If the newest generation of CD playback technology were as good as the promoters say it is, there would be no desire for music lovers to want to revisit the past.
Unfortunately, in their zeal to reject everything that was wrong with prior attempts to reproduce music, NOS proponents have thrown the baby out with the bath water. Yes, the brick-wall filter is bad and so is the digital filter, but a proper reconstruction filter, also called an anti-image filter, is an absolute requirement for any digital to analog converter. While 8X upsampling and extending the 16-bit sample to 24-bits with what is essentially noise doesn’t enhance the music, 24-bit DACs are superior to 16-bit DACs whether or not you use all the bits. Also, there’s nothing wrong with upping the sample rate provided you preserve the energy content of every sample.
The quality of a DAC can be quantified by measuring it's output signal and seeing how close it comes to perfectly representing the information in the recording (linear transfer function, linearity, noise).
The availability of fast DSP and accurate DAC's simply gives you more options in deciding how to decode the available information without the compromises that the early designers were forced to make.
Higher resolution DAC's (24 bit) allow you to use a lower level of dither (or none) when rounding the sample values generated in a digital filter.
Digital filter, Anti-alias/image filter and reconstruction filter are all the same thing you can choose all sorts of filter transfer functions depending upon how you prefer to make your compromises.
In the early days we saw CD players with 12 bit DAC's, no oversampling, no dither and wild deviations in low level linearity but these somehow did not get a mention.
2x, 4x and 8x oversampling Dacs are essentially the same animal except for a faster speed being introduced each time and possibly a more refined filter kernel allowing a more benign analog filter with each faster incarnation despite JB's misguided descriptions.
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I saw you are using Lavry Black DA10 DACs as well, how did it compare with Promi?
Highdfever,
Lavry Black DA10 is on the way. I will test it and compare to Promitheus DAC and let you know soon.
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I saw you are using Lavry Black DA10 DACs as well, how did it compare with Promi?
Highdfever,
Lavry Black DA10 is on the way. I will test it and compare to Promitheus DAC and let you know soon.
Yes please do. I have the Lavry and have been looking in new directions.
Mike
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I have the Lavry and have been looking in new directions.
Mccullinan,
How long have you had the Lavry? Do you like its sound? In my system it sounds fine but need to match with some kind of digital cable with XLR output connectors. I have already switched to unbalanced pin2 hot by using Hosa XLR-RCA adapters since all my components are RCA in and outputs (I would prefer the sound of balanced outputs but the technical support guy told me I should not do that). Do you know other way to keep the balanced ouputs in my system? :?What digital cable are you using? :scratch:Thanks in advance.
Regards,
Tan
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I have the Lavry and have been looking in new directions.
Mccullinan,
How long have you had the Lavry? Do you like its sound? In my system it sounds fine but need to match with some kind of digital cable with XLR output connectors. I have already switched to unbalanced pin2 hot by using Hosa XLR-RCA adapters since all my components are RCA in and outputs (I would prefer the sound of balanced outputs but the technical support guy told me I should not do that). Do you know other way to keep the balanced ouputs in my system? :?What digital cable are you using? :scratch:Thanks in advance.
Regards,
Tan
Ive had the Lavry about a year. I think it sounds great, very uniform top to bottom. Nice detail and musicality. If you use RCA it has to be in an unbalanced mode.For cable I am using an old MIT (Movies) and a glass toslink that I bought off of Audiogon (for the music)
Can you give us any comparisons between the sound of each DAC.
Mike
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any update guys?
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Finally got my DAC and Apollo active preamp.
What a long wait but no regret after connected to my system.
Will report later.
Chan
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Hi everybody,
My DAC is about 150 hours for now. Treble, Mid-range and also detail is really superb with replaced op-amp BB627 but I need to adjust
speaker set up to increase bass. Bass presentation has shown in polite way. Very good for Classical and Jazz music.
You need to try.... : )
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Agreed. Hard to find a DAC with this kind of performance within the price tag.
Hi Analogmart
How much improvement after replaced the opamp 5534? any other opamp you have tried besides the BB627?
Did you try the Vcap that mentioned earlier?
Chan
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Did you try the Vcap that mentioned earlier?
Chan,
According to Nick he personally does not like V-caps. He told me to try Mundorf Silver/Oil 0.1mF. I did try to bypass with Mundorf but I do not like its sound. I also tried Vit.Q PIO which is better than Mundorf to my ears and Vit.Q sound better in my Promitheus DAC. I will try Jensen PIO paper in tube in the future since these caps are expensive ($50-$60 a piece). Jensen Paper in tube caps are the best capacitors IMO. I had installed them in my Sun Audio 2A3 amp and was astounding with the sound performance right now. :thumb:
Tan
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Hi Tan,
You changed your DA10 to modded Altmann Attraction DAC? Altmann is NOS dac as well, so what is the difference in performance when compared to Prom?
Vitamin Q is not expensive here for this value (is it 0.1uf?), what is the improvement after adding it and where should I terminate it? Have you changed the Opamp for the Prom?
Chan
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Hi Tan,
For Jensen PIO caps, there are aluminium, copper and silver, $50 - 60 for a 0.1uf should be copper one, right.. I know the silver is v.expensive. But some diyers said Jensen has leakage problem after using for awhile.
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Hi, highdfever
BB627 is only op-amp that I've experienced. Detail is better, Mid band and upper is more refind than stock unit.
It cost me about $14 each in my country, which I think it really worth to invest.
By the way, please know that bass is not outstanding but it is there.
Some say that BB637 will give you more solid bass, but 627 is better in tonal balance.
If Rock music is your favorite, you should go to 637. Also AD797 is another choice to play with. :thumb:
The good thing is....DAC shows the right speed and timing whether you change or do not change Op-amp.
I've not has a plan to do Cap mod for now.
Does anybody has experienced in direct comparison between Prom Dac and Paradesia + ?
Cheers,
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Chan,
Jensen has three different values (less than 1mF/630V) of copper you can use for coupling and bypass. I use the 0.22 mF/630V copper foil/paper in tube for coupling caps in my Sun Audio amp but bypass with 0.022 mF vintage Guderman. The combination is excellent. You can use 0.1 mF
copper foil paper in tube to bypass but you need to try metallized polypropylene caps first before PIO caps in Promi DAC. The sound of PIO bypass caps will not be fast. I just ordered from Nicholas the new version of silver interface transformer (pulse transformer) which sounds much better than the first one and a copper one.
By the way I prefer the Promitheus DAC with some tweaks over the Lavry DA10 I had owned in my system with a fraction of price :thumb:
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Chan,
Jensen has three different values (less than 1mF/630V) of copper you can use for coupling and bypass. I use the 0.22 mF/630V copper foil/paper in tube for coupling caps in my Sun Audio amp but bypass with 0.022 mF vintage Guderman. The combination is excellent. You can use 0.1 mF
copper foil paper in tube to bypass but you need to try metallized polypropylene caps first before PIO caps in Promi DAC. The sound of PIO bypass caps will not be fast. I just ordered from Nicholas the new version of silver interface transformer (pulse transformer) which sounds much better than the first one and a copper one.
By the way I prefer the Promitheus DAC with some tweaks over the Lavry DA10 I had owned in my system with a fraction of price :thumb:
how's promi dac vs altmann?
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Anubisgrau,
One thing I have known that Altmann Attraction DAC with the battery fully charged (90-100%) sounds tighter and more punchier than the battery at 60-80% charged which sounds more relaxed and mellow. That is the beauty of Altmann DAC.
To compare with Promitheus DAC I could not say anything more since I just installed a new silver interface transformer. It sounds more body and powerful than Altmann DAC but it lacks the smoothness. Promitheus DAC needs to break in more and having little more tweaks to compete with other pricier DACs. However, the cost of $385 is an excellent big bang for a buck. :thumb:
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Tanchiro could you tell us how the Promitheus and Altmann handle complex passages.
I once had a non-oversampling Audio Mirror DAC1 (basically a DAC-AH) and it was a mess. It would get conjested and was unable to decipher details and especially with rock. It was somewhat more in the direction of analogue but I could not handle the huge negative aspect of it as detail would be lost or get all smeared together.
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I once had a non-oversampling Audio Mirror DAC1 (basically a DAC-AH) and it was a mess. It would get conjested and was unable to decipher details and especially with rock. It was somewhat more in the direction of analogue but I could not handle the huge negative aspect of it as detail would be lost or get all smeared together.
FJK,
I am not sure about the complex passages. I choose Promitheus and Altmann Attaraction DACs because they have not only smooth details and musical but also tremendous bass. If you are combining Promitheus DAC with tube gears you will hear the excellent performance of this DAC. I think the combination of Altmann DAC and BYOB amp's performance is another great one but you need to have high efficient speakers. Besides you do not worry about the congestion which would never happen to these DACs if you play rock music. :thumb:
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Hi FJK,
I am using Lite Dac50 (heavily modified) and to me, most of the similar prices DACs from China are not good in handling complex passages. I can easily hear distortion when listening to music such as Carmina Burana and other complex music. My Prom DAC is running for 200 hrs now and it is much better in handling complex music with better details, separation, sound stage, transient and speed. Only the vocal / mid band is not as good as Dac 50 probably due to the tube magic or maybe most of the chinese DACs were made to emphasis this area.
I believe the performance could be improved more after some modification of the Opamp, Cap and pulse transformer and isolation damping.
Chan
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That is encouraging that both of you say that the Promitheus can handle complex passages.
Although highdfever you say it is "much better". Does that mean there is no audible congestion/distortion or just a very small amount.
On one hand it would be nice to have tubes inside the Promitheus like your Dac50 but whenever I read comments about comparisons between non-tube and tube based Dacs there seems to be a common complaint that the tube based Dacs are like you describe. Less detail,speration, soundstage, transient and speed but great in the mids.
I think Dacs should first and foremost be able to perform their basic function. That is to convert the entire signal from digital to analogue (and without distortion). There is nothing upstream that will bring it back. is This is why I am very cautious in revisiting non-oversampling Dacs, tube or non-tubed. I think it is the same thing that keeps me from buying a very low powered SET amp that I sometimes lust for but I know would be just power shy for me. If it can't perform its basic role in driving my speakers then what good is it to me.
Having said that and currently running conventional oversampling, my battle is trying to counter the mechanical/eletronikey sound I get from it, which is why I still might give another non-os DAC a shot.
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Hi Music Lover,
I got the good result with 1.5 M. Belden 1694A digital cable from Bluejean cable. At least, in my system with Prom Dac, it
outperformed the other 2 cables which cost around $150-$200. This Belden shares the same strong point in speed and timing
with Prom Dac and it cost you only $15.
With my experienced, this cable can improve its performance by using cryogenic process too. After treatment, it can easily deal with complex music like overture song, image is stable. Mid range and upper tone got more transparent and better detail.
FJK,
Considered the cost of the Dac and ability to handle Rock or Calssical music, I can not give any complaint. :D
Mart,
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Only the vocal / mid band is not as good as Dac 50 probably due to the tube magic or maybe most of the chinese DACs were made to emphasis this area.
Highdfever,
I do not have problems in this area in my system. In the contrary, I do have the bloom of vocals and midrange. This part of Promitheus DAC sounds exactly like the Altmann Attraction DAC in my system. The vocals and midrange are the most part of my concern that is why I kept changing to find this best part in different DACs.
If you like to have the best vocals and midrange but not lack of details,he separation and bottom you need to order the new version of silver pulse transformer from Nick. He had tested this pulse transformer in his tube system before sent it to me. I do not think the idea of swapping op amp is the best idea. Besides you need to try to connect your Promi DAC to the Promi TVC you will see how revealing is your music. :thumb:
Regards,
Tan
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Hi Tan,
I found the sound from Prom Dac is just right, more balance than my tube DAC. I would get a silver pulse transformer from Nick who has promised me earlier due to the long waiting time. Hope he still remember. aa
I am using Apollo preamp now but I found that one of the channel is out-phrase and I need to revert the (+ & - ) of speaker cable for my left speaker in order to make it sound right. Not sure which channel (left or right) got problem. Any method or simple equipment can check this out? Initially I was so surprised to hear why suddenly the sound stage is so hugh and extend towards the left and right, but then I realized that there is no imaging and vocal is not in the center.
Besides, I found there is a hum sound coming out from my speaker (not the Apollo problem because my GG preamp also has the same problem and that's why I was using Luminous Axiom Passive Preamp earlier and I finally found Prom TVC). There is no problem and the background is so quiet when I use the passive mode (BTW, TVC is much better than normal volume/resistor passive), but the hum sound came out immediately once I turn to active mode. I have tried to disconnect all the interconnects and sources, just connected the preamp and power amp (tried both ground or unground power cables) but the hum sound is still there. What would be the problem and any suggestions?
Hi FJK,
I havent tried many DACs with big name, but I like the sound of my friends' Benchmark DAC 1 and Apogee Rosetta. They both sound real with dynamic sound, good in handling complex musics and of course, no audible congestion/distortion but some may said not musical enough. Well, it is not fair to compare Prom DAC to them because it is only around 1/3 the prices of Benchmark and 1/5 of Apogee but I can tell that Prom is not far from them. Prom can handle complex music as well, may not as good as the above DAC but I found the music coming out for Prom is more listenable, can we say more musical... :wink:
I hope after some modification (such as silver pulse transformer, BHP damping, Cap...etc, anyway, not expensive) as suggested by other user, the vocal / midband will be just like the tube Dac, and other areas such as definition, soundstage, imaging, speed and timber will close to Apogee.. :lol:
Enjoy
Chan
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Hi Tan,
My DAC is also comes with silver pulse transformer but I never experience the difference between normal version and this one.
According to Dac manual, Nick said, "The NE5545 has a good midrange and mid bass but lacks in the areas of transparency and highs
extension, PRAT, speed and lower bass. The N5545 is sitting in a turn pin socket allowing you to change the OPAMP used. As long as
you stick to a single opamp, any other opamp can be used as long as their power suupply can withstand 13.6V."
So far as I know, The operation voltage range in most opamp is 5v -15v. so, it is fine to experience by yourself. Swapping opamp is as same as swapping tube to fine tune your preference sound and performance. :thumb:
This is what Nick replied me about BB627.
Mart,
The 627 would be better sound staging with better highs and a more refine sound but less bass
What digital cable are you using?
Cheers
Nicholas
Next step,
I ordered 1.5 Belden1694A BNC type from Bluejean to compare with the RCA version with Cryo treat.
I should get it about next week. :P
Best Regards,
Mart,
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Highdfever,
I do not have problem with vocals not in the center. You would also need Nick's power cable for your Promi DAC and I just found out my experience of not tight down (take off the four screws that hold the DAC board to the bottom plate) the DAC pcb it would give you more musicality and dimensionality. One more thing if you can find to replace all wires around the output transformers and connectors with a pure copper plated with silver this would bring the DAC to another level of smoothness and clarity (dead quiet background). :singing:
Analogmart,
You need to ask Nick the new version of silver pulse transformer wounded on thin laminated donut core (0.05mm thickness). I had the old copper one it sounded very bright then I wounded another one myself with copper 30 ga it still sounded bright and thin. The new silver pulse transformer give you a thick sound with decays but not lack of separation, musicality and dimensionality. I am also very astounding the amount of defined bass coming out from my VR1 monitors (I do not need a subwoofer) in my big living room. :dance:
I use Zu Ash digital cable and all custombuilt ICs. Now the DAC is connected to TVC with an Audioquest BNC digital cable. Remember my SB3 is modded with a SC947-02 pulse transformer and I built myself a linear PS for SB3. What source do you have?
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Hi Tan,
I'm using CAL Delta Transport. Hagclock is on the way for modding this old machine.
Belden digital cable is currently use. (replaced Eccosse and VH audio pulsar IC)
After Prom Dac, signal go to TVC REF 4.
I'm not sure about thin laminated donut core (0.05mm thickness) in my DAC but cable itself is black color.
What color you have?
Two signal cables after output transformer use red and white cable with
promitheusaudio screened on it skin. :thumb:
Mart,
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Has anyone communicated with Nicholas lately? I've been waiting for a usb module for the Promi DAC for almost 5 months. He hasn't responded to my last three e-mails asking about its status. Usually he responds promptly, so I'm just wondering if something has happened. Has anyone ordered and received the usb module?
Thanks,
Bob
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Has anyone communicated with Nicholas lately? I've been waiting for a usb module for the Promi DAC for almost 5 months. He hasn't responded to my last three e-mails asking about its status. Usually he responds promptly, so I'm just wondering if something has happened. Has anyone ordered and received the usb module?
Thanks,
Bob
Five months! Wow! Thats insane. Good luck. You must really like it.
spud
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Has anyone communicated with Nicholas lately? I've been waiting for a usb module for the Promi DAC for almost 5 months. He hasn't responded to my last three e-mails asking about its status. Usually he responds promptly, so I'm just wondering if something has happened. Has anyone ordered and received the usb module?
Thanks,
Bob
Five months! Wow! Thats insane. Good luck. You must really like it.
spud
Hmm... You showed up here on the forum only a few days and most of your posts are attacked against Promitheous. What is your intent?
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Has anyone communicated with Nicholas lately? I've been waiting for a usb module for the Promi DAC for almost 5 months. He hasn't responded to my last three e-mails asking about its status. Usually he responds promptly, so I'm just wondering if something has happened. Has anyone ordered and received the usb module?
Thanks,
Bob
Hey Bob,
Most of my second system's components are from Nicholas Chua at Promitheus Audio which I only took at most two to three months to get them. I talked to Nicholas last week he told me my Apollo preamp will be done in a month. Any new products of Promitheus Audio should have tested thoroughly until he got a best sound out of them. You also should know best sound quality products with affordable prices conducted by the owner himself usually need more times not like a mass products through dealers.
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Has anyone communicated with Nicholas lately? I've been waiting for a usb module for the Promi DAC for almost 5 months. He hasn't responded to my last three e-mails asking about its status. Usually he responds promptly, so I'm just wondering if something has happened. Has anyone ordered and received the usb module?
Thanks,
Bob
Five months! Wow! Thats insane. Good luck. You must really like it.
spud
Hmm... You showed up here on the forum only a few days and most of your posts are attacked against Promitheous. What is your intent?
I did think I was attacking Promitheus. Sorry if you thought so. Just telling it like it is. I have no agenda against Promitheus. Don't you think 5 months is a long time to wait? Just adding my 2 cents thats all. It may be a good product for the price but 5 months. C'mon man, lighten up and smell the Roses.
spud
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Hi - Yes, same story with me. I've been waiting a few months for my USB module as well. Oh well - can't win them all and I am VERY happy with the sound of the DAC (currently using with a Trends UD-10 USB convertor).
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Nicholas got in touch with me and said he didn't get my emails. I know he's had problems in past with spam filters, etc. He said the module should be ready to send out soon. I'm looking forward to hearing the module with the dac.
Bob
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Nicholas also responded to me to state that the USB module had taken a little longer to develop than anticipated, but that it should be arriving shortly. I am very happy with this and have always been extremely happy with the DAC (see my first post in this tread - where I also mentioned that I knew Nicholas would send the USB module only when he was entirely happy with it, which he now is) ! :D Now to await more info on the TVC Signature line :drool:
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To be more happier with the DAC you should tweak it more with Black Hole Pad (BHP). This is the link to my gallery
http://www.audiocircle.com/index.php?action=gallerylastup&cat=0&pos=0
http://www.audiocircle.com/index.php?action=gallerylastup&cat=0&pos=1
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This is a very educational thread. I have really enjoyed reading the whole thing. Thank you all.
I am currious about the choice of stainless steel for the plate though. I always thought that a non magnetic baseplate was a better choice for most circuits, even those that are transformer coupled. Maybe someone with more knowledge can chime in and set me straight. Also, I see a lot of talk about bypassing an output capacitor. Is there a coupling capacitor just before the O/P transformer?? That doesn't make sense to me. Perhaps it's the power supply you are all talking about. Again, someone can chime in and set me straight on this too. Thanks in advance.
Finally, I too am a little leary of jumping in, even though it looks like a lot of DAC for the money. I had a DAC AH at my house for a while and it sounded promising but it was very disconnected. Actually, it was blatently distorted on complex musical pasages. It's just a pile of parts in the garage now. Lesson learned. The Promitheus and Mhdt offerings look very tempting but I don't want to get another DAC that cannot handle complex musical passages either. BTW, this has nothing to do with tubes, op amps, capacitor tweaks or transformers. I'm talking about the basic DAC design. For example, the Audio Note Dacs don't have this problem at all. In fact, quite the opposite. Is this distortion phenomenon with complex muscical passages a thing of the past in today's sub $1000 NOS dacs?
Thanks to everyone for any experience you can share.
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I am currious about the choice of stainless steel for the plate though. I always thought that a non magnetic baseplate was a better choice for most circuits, even those that are transformer coupled.
Stainless Steel is non-magnetic.
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Thanks John, I didn't know that! :duh:
One down, two to go!
QE
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I had an MHDT Paradisea on loan for a while and didn't think it had a problem with complex stuff.
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Is this distortion phenomenon with complex muscical passages a thing of the past in today's sub $1000 NOS dacs?
I have owned an Altmann Attraction DAC in my main system and Promitheus DAC in my second system I don't experience any distortion with complex music passages at all.
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I've had both versions of the MHDT Paradisea and the Audio Sector Dac. Which was also a NON OS Dac. None of them had any problems with complex music. I listen too music and watch movies through my current Paradisea..no problems at all.
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Thanks guys. Your comments are very helpful. FWIW, I bought the little Ah mostly as an experiment, for fiddling around and discovery. I guess that it's not a fair representation of the bargain DACs that are manufactured today. This is very good news indeed.
Right now my baseline for 2 channel CD playback is the Audio Note 2.1X signature dac. I've been using it for quite some time now. Right or wrong, that's what I'm used to. I have a Benchmark DAC that I use for my meager home recording studio hobby and it's really wearing on me. I would like to get something that is more in line with my Audio Note DAC so that I don't have to mentally switch gears, if that makes any sense.
Anyway, that's why I was asking all of the questions. I do appreciate all of the information that is being exchanged here. Thanks!
QE
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...I have a Benchmark DAC that I use for my meager home recording studio hobby and it's really wearing on me. I would like to get something that is more in line with my Audio Note DAC so that I don't have to mentally switch gears, if that makes any sense...
So, what's wrong with the Benchmark DAC? Just curious...
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Hi,
Just thought I'd chime in. Sorry for the long post, but bear with me. Been following for awhile. I'm an old audiophile - was in the business "back in the day" - 70's actually, and into the early 80's. Have heard and sold some great stuff. Been away for awhile but finally started upgrading a 20 year old Dahlquist based system about a year ago. I'm still on a strict budget, but have done lots of reading during the entire time since I left and began making some choices within the past year. My Dahlquist's were due for replacement. I actually started by replacing them with some used Vandersteen 2CE's. Nice - they do alot right - but one day I'll probably go the planar/electrostat route. Since, in some ways, I missed the entire CD era- having owned nothing more than run of the mill big box store machines, and since I had been downloading music since the late 90's, I began to search for a digital format that made sense for me. I also have an extensive record collection, and even after letting my Linn go, I still had and had taken good care of my first turntable - a vintage Thorens TD- 160, from 1975 - stock with a new birch bottom and some homemade feet. Anyway, I settled on a Squeezebox early this year, with an eye to eventually purchasing an outboard DAC. Nowadays, I rip CD's, using EAC (Exact Audio Copy) into WAV or Flac files. And I recently turned my old computer into a dedicated music server. In the meantime, I purchased a Conrad Johnson MV 60SE on Audiogon, fulfilling an old dream of owning some tube gear. I'm happy with it, and it is certainly an improvement over the amp sections of the vintage NAD and Yamaha integrateds that I had left over from before. But this meant that I still only had the NAD or Yamaha's preamp section to run the CJ through. After lots of reading and listening in local shops in the Seattle area and lots of thinking about what I really wanted to do (what about home theater etc..), I decided that I really wanted to go with the simplest signal path I could find. I started checking out, reading about and listening to passives and stumbled onto the TVC method. I read about the Music First, the Paradesia etc. and somewhere in there, stumbled onto the Promitheus TVC. After a number of emails with Nicholas, I finally took a leap of faith on a basic Promitheus TVC SE, with 4 single ended RCA inputs. I live in an apartment, second floor with thin walls, so I have to keep the volume down quite frequently. As soon as I placed the TVC in my system it was apparent that I had made the biggest improvement to its sound to date. And, as you may have read, by design, it sounds great at lower volumes. (Of course, I like it loud too and with my relatively small room, I could create plenty of spl's with this setup).
I had lots of ideas about what to do next, and had originally thought about upgrading my analog gear, but finally settled on simply getting a new cartridge and an entry level Cambridge Audio phono preamp for now, due, in part, to my continued emails with Nicholas, who kept encouraging me to try his DAC. Nicholas is a gem of a person to work with. Incredibly patient with questions about inputs and options. Bottom line is that I finally decided to take a second leap and give it a whirl. Customer service goes a long way with me.
It arrived last week, and straight out of the box, the sound of music coming out of my system with the Promitheus DAC is orders of magnitudes better than the stock DAC in the Squeezebox. Perhaps at this point you're saying 'well, geez, I hope so!', but really, we audiophiles tend to spend a lot of money for what, at least from a big picture point of view, is nearly infinitesimally small amounts of improvement. This is not small. With selections I'm very familiar with, I hear nuances, new instruments and additional voices that were simply not audible in any previous version of any of my systems over the years, and immediately apparent compared to what I had a week ago! It's early, but I only expect this to improve.
At this point, I'm contemplating stopping for awhile and just enjoying the music for the first time since I started upgrading. The sound is dynamic, smooth, not bright or muffled - just excellent timbers of acoustical instruments, great slam on electric or electronic bass and very realistic vocals. Separation of individual instruments are way improved, and my sound stage is much, much higher, as well as wider and deeper. It does not take an audiophile's ear to hear most of these differences, in my opinion.
The latest version of my system is still not super hi- end, but it's well respected, and well rounded, and now, very musical. Nick's DAC and TVC are remarkable. Being a vinyl fan, yet not dogmatic about it, I had still preferred my vintage analog system for a good portion of my collection in which I had both analog and digital versions. Now, only a very few, if any, analog versions of my collection are likely to be preferred over their digital counterparts with the Promi DAC in place. The pace, the PRAT (as they say), the homogeneity of sound is all their with the Promitheus equipment in place. The TVC was a big improvement in my system, but the DAC was even bigger. For now, I have no tweaks planned internally for either, but, in time, perhaps. I've listened to a few other DAC's locally, but I'd venture to say that my experience with other DAC's is not as extensive as some. However, my ears are still good and I trust them and comments from others who have casually dropped by during my latest rounds of upgrades have continuously commented on the improved sound. I know I'm on the right track. I have no reservations whatsoever recommending Nicholas's DAC (and his TVC too)!
Thanks!
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Dainapoo,
I am glad that you like Promitheus DAC :thumb: and believe your DAC is a new version one compared to the first version I have own. Does your DAC have a wooden board built under the pcb board? Nicholas told me that the idea of a spruce board under the DAC board (like in Altmann Attraction DAC)makes it sounds more musical instead of more digital. He has some kind of an exotic wood from Malaysia and build into the DAC. What is your opinion about your DAC soundwise?
Regards,
Tan
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...I have a Benchmark DAC that I use for my meager home recording studio hobby and it's really wearing on me. I would like to get something that is more in line with my Audio Note DAC so that I don't have to mentally switch gears, if that makes any sense...
So, what's wrong with the Benchmark DAC? Just curious...
There is nothing wrong with the Benchmark DAC1. It's a fine DAC of it's category, but I can't tolerate it anymore.
I bought my DAC1 when it first came out, long before Stereophile wrote anything about it. I didn't make the purchase based on any hype or wonderful reviews, it was more about trying to get the right tool for the right job. I was under the impression that studio gear such as dacs and monitors should be ruler flat, unforgiving accurate, and have no personality of their own. This is a philosophy that I no longer subscribe to. I have no problem that it works well for others, it's just not for me. I hope that makes some sense.
Since I communicate better with technologies such as non-oversampling dacs and single ended triodes (or pentodes), this is how I have been rebuilding my home studio. (Sold my Mackie HR824s too. Replaced them with the Almarro A205A and Omega Max Hemps.)
So it's not really a right or wrong statement that I was trying to make. It's just the direction that I need to go. To anyone who loves their Benchmark DAC, please don't stop loving it on account of me.
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Hi Quiet Earth,
Please tell us more when you get Prom Dac and compare it to your Dac1.
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Thanks analogmart. That may be a bit of a wait. With the holidays nearly upon us, I will likely wait until 2008 to make a purchase. Right now I'm still in the homework stage of searching for a good value in a NON OS dac. Part of me really wants to save up and upgrade my home stereo to a 4.1x dac, then move the 2.1X into the studio. The rest of me says just use what I have and be grateful. I'll probably split the difference somewhere down the line next year. I'm pretty sure I can get at least 400 for my Benchmark, or use it for a softsynth DAC.
If/when I pick up the Promitheus DAC I will post my impressions here and bump the thread. Right now there's turkey dinners to prepare, travel expenses, and Christmas activities creeping into the checkbook. Tis the season. :)
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I bet that output transformer in Prom Dac will makes you impress!! :thumb:
(based on your Audio note standard)
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*subscribed*
aa
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Please help us to post your votes for Promitheusaudio to have its own forum
here
http://www.audiocircle.com/index.php?topic=47718.0
THank you
NIcholas Chua
Promitheusaudio
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Promitheus C-Core DAC - I went this route because I wanted to hear everything. I don't really want filtering and correction at any stage of Red Book reproduction beyond the necessary. Ideally, if I could chew on a cd and the music would vibrate through my mouth and into my ears, I would opt for that, albeit it would be too selfish as I love to share music. This is just an opinion. I feel hifi it is about allowing the technology to optimise itself with humane propositions - natural and refined materials to compliment the resonance of the technology , openness with regard to the full sound that is produced, respect of the sensitivity of our ear organ. Purity is also just an idea that sits alongside the proposition of hifi and the idea is just as attractive as its implementation. This is not 'hairshirt' in any way, it is a route in tune with our environment and how we learn to understand complex sounds, not a wall of information which other approaches value, an exciting isolated experience, but not an integral visceral one that is linked to the experience of living in sound. Having said that, I am not a fan of valves for their often confused midrange. I am a firm believer that all materials can be to resonate efficiently under the correct conditions and valves are an easy way out of careful design. Sold state can be accurate because it resonates with more precision. Making solid state sing is an art to which the Promitheus DAC is a school of.
You won't be surprised by the set up then: Promitheus C-Core Solid State DAC, 47 Labs Shigaraki Transport, First Watt F-1 Amp, Lowther DX4 on a custom build open baffle, and soon to have Promitheus C-Core Transformer Passive Pre, once I sell my Audio Synthesis Decade Desire Monoblocks, which are themselves a slice of English Hifi heaven, but obviously too much for my Lowthers to take! Any interest out there, let me know. Best wishes Nick of Promitheus. Micha
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Hi tanchiro58,
Sorry it took so long to reply. Been changing jobs. Yes, I believe that's right - it is the newer DAC with the board underneath. I'm still very satisfied with the sound. It's a very big improvement over the Squeezebox's own DAC - that's for sure. Virtually everything I've played through it has been a revelation - meaning hearing a nuance or an instrument that I had not noticed before. It's getting near break in, but it's been sweet and 'analog' sounding pretty much since day one. I'm experimenting with different gain settings at the moment. I'm currently running Signal Cable's Silver Resolution Digital Coax between the SB and the DAC and their Analog Two cables between the DAC and the Promitheus TVC. The DAC is connected to power via their Magic Power Digital Reference power cable. I'm not a cable expert, but since finding SC's stuff on Audiogon, I've been very happy with the sound, construction and value. I also use their Magic Power power cord for my Conrad Johnson amp. Might try Nicholas's cables one of these days. I'm using stock Nyutah wood feet. Thanks!
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Hi tanchiro58,
Sorry it took so long to reply. Been changing jobs. Yes, I believe that's right - it is the newer DAC with the board underneath. I'm still very satisfied with the sound. It's a very big improvement over the Squeezebox's own DAC - that's for sure. Virtually everything I've played through it has been a revelation - meaning hearing a nuance or an instrument that I had not noticed before. It's getting near break in, but it's been sweet and 'analog' sounding pretty much since day one. I'm experimenting with different gain settings at the moment. I'm currently running Signal Cable's Silver Resolution Digital Coax between the SB and the DAC and their Analog Two cables between the DAC and the Promitheus TVC. The DAC is connected to power via their Magic Power Digital Reference power cable. I'm not a cable expert, but since finding SC's stuff on Audiogon, I've been very happy with the sound, construction and value. I also use their Magic Power power cord for my Conrad Johnson amp. Might try Nicholas's cables one of these days. I'm using stock Nyutah wood feet. Thanks!
Dainapoo,
Good to hear back from you. If you do not mind would you have a chance to take a picture of your Promitheus DAC with a wooden board underneath the pbc (what kind of wood are you using?)? I have tweaked around my Promi DAC using different wires and will try pure silver wires. Right now I wired around the OPT with double stranded 30-35ga copper silver plated and digital inputs and outputs RCA. The sound leans more to analog but little lost of details. I am using Zu Ash digital cable (the most musical cable I have owned) and power the DAC with Nick's PC.
I got the Promitheus Apollo preamp which is a good match to the DAC. I am tweaking around with the preamp by replacing the step attenuators and the rotary switch and replace the stock caps with BGs. Next I will replace all wires with pure silver wires since it sounds too warm to me.
Regards,
Tan
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Hi Tan,
Yeah, I think I can do that. I'll see about getting a pic and posting it. So, how are you liking the Apollo? You had the TVC before, right? How do they compare? It's interesting that you mention warmth when describing the Apollo. Would you describe the TVC in a similar manner? The reason I'm asking is that I've been out of the game for quite awhile until recently. I was in the business back in the 70's and early 80's, and for a long time, when I did listen to new digital equipment, it was what I'd call lean and clinical (or scratchy etc - you know what I mean - the old digital sound). It's only been in the last year that I've been replacing all my old equipment, which is how I stumbled onto the Promitheus. My decisions are getting better the further I go- my first two decisions were based on a combination of old thinking and lack of funds. First, I found some Vandersteen 2CE's locally and cheap, which was a recommendation from an old audiophile friend of mine. I went to a local dealer and listened to them and they were 'good enough', although my friend and I have always had slightly different tastes. The second was the CJ amp - MV 60 SE- it was just a holdover from my days in the biz - I'd never owned tube gear and wanted to. I found it locally through Audiogon. Somewhere in there I got the Squeezebox and I still had my first turntable - a 1975 Thorens TD 160 - which I've done a couple of things to, but is basically stock. (Sold a Linn I had 12 years ago or so). I'd hardly owned any cd's but had gotten pretty sophisticated in downloading and ripping to hard drive and turned one of my old computers into a music server for the SB. Anyway, what I'm getting at is, if anything, this system sounds a little warm to me. I would admit that I've always liked a slightly brighter sound that some of my other audiophile pals, but, having decided to just keep the Thorens going for now with a little Cambridge Audio phono preamp, I replaced my Grado cartridge with a new Ortofon 2M. It's got a brighter sounding character and now my analog rig is actually brighter sounding than my digital source. So, I'm in the process of trying to figure out where the 'warmth' is coming from. I suspect the combination of speakers and amp are part of it, but I'd like to hear what you think.
Take care,
Daina
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Hello Daina,
Actually the first pcb DAC was harsh and stiff and I tried to tweak around until I messed up with the solder joint (could not solder the components to pcb). I asked Nick to replace the new pcb DAC. Finally Nick sent me a new pcb and a new pulse interface transformer. I did not do any further modification on the pcb due to my previous bad experiment. After soldering the new pcb to the DAC I noticed there was a big improvement sonically compared to the previous PCB. Like I said I only replaced wires and padded the components and transformers of the DAC with Black Hole Pads. I got good result with warm sounding but less details. You are right maybe the sound is too warm because of the rest of the system (mine is all tube except the sources SB3 and DAC). I am awaiting the Burson Discrete Opamps to replace the stock opamps NE5534s. I will let you know once the new opamps broken in.
The Apollo preamp is another higher level of passive TVC (tube buffer+ TVC). I have owned couple TVCs before and know that any TVCs in my system just give musicality and smoothness but no body or punchy sound. Therefore, the Apolllo preamp has added some juice to my system. However, since I would like to bring it to another level of musicality I have started to do some more tweaks especially my concentration is in the signal path. I will show some pictures of my tweaks for the Promitheus DAC and Apollo preamp.
(http://www.audiocircle.com/image.php?id=11978)
Regards,
Tan
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Hello i am new to this forum (from Norway, so sorry for my bad English), i am looking for a dac to use in my tube based system (my first dac ever) and were thinking about the moodlab concept but then i came across the Promitheus on this board and found it to be very interesting. I was wondering if you all still are extremely satisfied with its sound? The silver pulse transformer option how does it better the sound of this dac? How much more do i have to pay to get anything better? I hate digital "hizz" in upper midrange, is there any "hizz" and hard sound with this dac?
That was alot of questions, i hope someone will answer... :D
Sincerly Svein
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Hello i am new to this forum (from Norway, so sorry for my bad English), i am looking for a dac to use in my tube based system (my first dac ever) and were thinking about the moodlab concept but then i came across the Promitheus on this board and found it to be very interesting. I was wondering if you all still are extremely satisfied with its sound? The silver pulse transformer option how does it better the sound of this dac? How much more do i have to pay to get anything better? I hate digital "hizz" in upper midrange, is there any "hizz" and hard sound with this dac?
That was alot of questions, i hope someone will answer... :D
Sincerly Svein
Milenko27,
So far I have owned more than 10 DACs (upsampling, oversampling and NOS). I sold the others and keep my Promitheus DAC and Altmann Attraction DAC. Both are NOS DACs and do not have digital sound ("hizz in the midrange"). I also have tweaked the DACs so I can have the sound I expected in my system. It also depends on your other components of your system. That is why people called matching system or system synergy.
Talking about Promitheus DAC. IMO Nicholas Chua designed this DAC based on his knowledge of Audio Note and/or Altmann Attraction DACs with a fraction of price. I do not know what sound do you prefer for your system but I do like warm, musicality but not less details especially separation. If you own Promitheus DAC and tweak around you will get what you expect soundwise. That is the beauty of it. Besides the pulse interface transformer is very important to the side of transmitter and receiver in the digital part and also the jitter reduction.
Hope I answer your questions but please do not hesitate to ask more questions if you are interested in modifying and tweaking the DAC.
Good luck and take care,
Tan
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Thank you for answering my questions, i believe i will order the Promitheus dac next month, has to get over the christmas rush first. I have a Cardas high speed data cable (75 ohm) will that cable work ok with this dac (i use cardas cables everywhere else in my chain and am happy with that)?
Sincerly Svein.
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I have a Cardas high speed data cable (75 ohm) will that cable work ok with this dac (i use cardas cables everywhere else in my chain and am happy with that)?
Svein,
If your system is solid state you can keep your Cardas and ordering the Promitheus DAC which will add the warmest tube sound to your system (if it is analytically sounding). I have to warn you the DAC is more to the tubey sound even though it is a solid state DAC.
Tan
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tanchiro, would you say it is warmer than the paradisea dac? how would you describe their differences?
(i own the paradisea and am interested in getting the promi). thanks.
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tanchiro, would you say it is warmer than the paradisea dac? how would you describe their differences?
(i own the paradisea and am interested in getting the promi). thanks.
I would say I am not sure about this comparison since I do not own Paradisea but I listened to it in my system before. Paradisea DAC has warm and musical sound based on the output tube stage but I still heard the digital sound unless it is modified (output caps and pulse transformer) and Promitheus DAC sounds warm and more juice too but very little digital sound since it has pulse interface transformer and output transformers which are wounded same as TVC trannies. However, I have tweaked it around to get the jitter reduction as much as I can. After tweaking the Promitheus DAC I always compare to my Attraction DAC which has the warmest sound but not less details and more less jitter. :thumb:
Tan
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I really love a warm sound, my set up is tube based, but it is not extremely warm, so i think a dac with tube like warmth would make me happy... :D
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Hi Daina,
I just finished installing a pine wood board under the pcb DAC. I have noticed the sound has more smooth details and more sweetness in midrange. Here is a picture. Did you have like this?
(http://www.audiocircle.com/image.php?id=12807)
Sorry for the blurred pictures
Tan
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i've been talking with nick lately and have decided to put in an order for one. i am also considering hooking up my dvd player to it for 2 channel HT (i only have stereo for my "HT"). however, i am not sure if it is a good idea as i am not very happy with the paradisea's "HT" performance but i loove it for 2 channel music. anyone doing this with good results? i am currently using my denon 2930 dvd player as stereo source for movies (HT).
thanks.
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For my own HT setup this is what i used
32" Sony LCD
Computer as the source
Our USB converter
DAC
TVC
45 Set amp
Fostex 206 in a Mass Loaded Speaker box
Never had problems with dynamics or fire fights
I use this to watch the entire season of 4400 and battlestar galactica
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sounds good. i will put in my order in january and see how it goes. thanks nick.
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I will also order a dac when January comes and another paycheck...
I can hardly wait :drool:
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Going to order one this saturday, but i have one question? does the unit come with a power cord or do i have to buy one myself?
I saw the recomandation of their own powercord, but it had a three pin wall socket, here in Norway we have two pin sockets?
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Just thought I'd post after a bit of a revelation last night after listening to my promitheus DAC after a recent tweak....First off, I bought the DAC second-hand from AC or audiogon and received it back in December...In a head-to-head comparison with my modded Paradisea DAC, I preferred the sound of the stock Promitheus using either a Denon 2900 or SB3 as the source...In fact it was so night and day that I sold the Paradisea...My take: better PRAT, impact, soul, body and less mush...I think the Paradisea through my SET system (Welborne Ultrapath-> DRD45 -> Bastani Prometheus OB speakers) was just too soft sounding and lacked any bite...
So, anyways, last night I installed a pair of the Burson discrete op-amps using a Hovland musicap (0.33uF) bypass cap and WOW!!! Right off the bat without any real break-in, the sound was simply stunning...I could now hear the piano and guitar string decay...the notes seemed to hang in the air alot longer...I could wax poetic for awhile about how impressive the sound was...I cant say enough about giving these inexpensive circuits (~$100USD) a try in your DAC...Nick deserves much props for putting in the DIP sockets to enable very simple op-amp changes...
I think I'm gonna leave well enough alone for awhile and focus on improving my SB3 as I still prefer CDs over streamed FLACs...
Cheers everyone and happy 2008!!
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where is jb? i want to know what he has built. he blocks pms.
jb, here me now and contact me...
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Hi, posternutbag2000
Where did you put bypass cap in the dac?
My Burson is coming on the way, it will replace BB627AP.
Cheers, :D
Mart
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Hi, posternutbag2000
Where did you put bypass cap in the dac?
My Burson is coming on the way, it will replace BB627AP.
Cheers, :D
Mart
Here is the link of how to install the Burson Discrete Opamps with bypass caps:
http://www.bursonaudio.com/Burson_Discrete_Opamp_101.htm
It had a stunning sound too in my Promitheus DAC after replacing the NE5534 opamps with Burson Discrete Opamps.
Good luck,
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Like Tan said (and thanks for the recommendation of the Burson discrete op-amps :thumb:), I installed the bypass caps as Burson indicated in their 101 op-amp tutorial...basically for the single version which I used, it was across pins 4 and 7 on the op-amps...a bit tough to solder with the large leads on the Hovland caps but in the end got it to work fine...
Still breaking in but pretty killer, imo...
ymmv... :P :P
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Dac ordered :D, i guess now it is only to wait.
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Do you need to know how to solder to be able to switch op-amps?
Have anyone tried different types and what do you think of them?
Been reading about the Burson op-amps, sounds great, but looks difficult, how do you get the ground, do you solder it to the rca outputs?
Again with the questions....
Best regards
Svein from Norway
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For your basic op-amp swap, you do not need to solder as Nick provided the simple plug-and-play 8 pin sockets...for the Burson discrete op-amp change, you do need to solder but its a fairly painless procedure if you just want to swap out the op-amps as all you'll need to do is solder the ground wire from the bursons to the RCA output or a similar grounding spot (I used the transformer lead which is connected to the RCA ground)...Burson also recommends as an improvement installing a capacitor (0.1 - 1uF) across two of the Op-amp pins which is bit more difficult but not too hard....
Hope this helps and if you need further help let me know...
anyone else tried any other op-amps?
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Hello, and thank you very much for the quick response. My dac is being built now, so it will take some time, will let it burn in before i try alternative op-amps, and will write back on this forum when it is time to take the next step. It is really great to read about all the satisfied customers when i finally made up my mind of which dac to buy, and that it is so easy to tweak....
I am really looking forward to get the dac in my own house and sitback and relax :D
Best regards
Svein.
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Hi Prom DAC Lover,
If you do not plan to buy Burson discrete op-amp, BB627AP is good enough to replace stock unit.
The sound is more refined and detailed, and more punchy bass too.
The price of some highend Op-amp is too high for me, which in this case, I better buy Burson instead.
BTW, I still could not compare the sound b/w BB and Burson because my digital receiver CS8414 is dead, my bad :duh:
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If more people like the opa627 i can get them and install them for you as an option
I myself do not seem to like the opa627 sonic character and prefer the stock Op-amp. I tried most of the other op-amps and never like them
Perhaps the burson would be much better
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Perhaps the burson would be much better
Yes that is true the Burson Discrete Opamps sound way better than the stock opamps IMO. I should say the pair of single Burson opamps sound very neutral with lots of details and it is everything that stated in the Burson website. :thumb: :thumb: :thumb:
(http://www.audiocircle.com/image.php?id=13225)
Why do I have to spend money to try out another opamps for? Once again it depends on your sonic tastes.
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Hi Tan,
Where did u connect the ground wire to? Did you solder any by-pass cap in the Burson Discrete Opamps? It mentioned that the cap between Pin4 & 7 of the opamp, any marks/indications of the pins in the opamp and what about the polarity of the cap ?
Besides the details, any other major improvement after opamp changed?
B. Rgds
Andis
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Hi Tan,
Where did u connect the ground wire to? Did you solder any by-pass cap in the Burson Discrete Opamps? It mentioned that the cap between Pin4 & 7 of the opamp, any marks/indications of the pins in the opamp and what about the polarity of the cap ?
Besides the details, any other major improvement after opamp changed?
B. Rgds
Andis
Andis,
If you look closer to the above picture you will see the two "black wires" going from the Burson Opamps to the screw at the main power tranny where there is a ground wire located.
I use Wima film caps to bypass at pin4 to pin7. As you know film caps are not polarized so you do not worry about doing wrong. However, choose a smaller caps is best way to do. Good luck.
Here is another picture showing the two square blue green caps.
(http://www.audiocircle.com/image.php?id=13343)
There is a big improvement over the stock opamps in sonic exactly what Burson website described.
Tan
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Tks Tan,
I think I will order this opamp, should I just mention to Burson that I need a pair of single opamp to replace NE5534? I found the price is around AU$100 for the single opamp, is it correct?
Cheers
Andis
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Tks Tan,
I think I will order this opamp, should I just mention to Burson that I need a pair of single opamp to replace NE5534? I found the price is around AU$100 for the single opamp, is it correct?
Cheers
Andis
Here is the link
http://www.bursonaudio.com/Burson_HDAM_Module.htm
And the price: if you buy directly from Burson I guess a pair of single opamp costs AU$85 which replaces your NE5534s
http://www.bursonaudio.com/Sales.htm
After installing the Burson Opamps you can not put back the lid or cover of the DAC unless you manage to bend the Burson opamps. Good luck.
Tan
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Hi Tan,
Some more questions:
Some user claimed the performance of Burson discrete op-amp was not good (AD825 is even better) but the problem may be due to voltage supply issue. It claimed the voltage supply is at least 15v in order to optimise this op-amp to function normally. So have you checked if Promitheus DAC provide enough voltage to power the op-amp? (May be Nick can help to answer this question)
I am not technical guy, so if I need to modify the power supply of the DAC in order to change the Burson discrete op-amp, then I am not able to do it. :duh:
Have you tried different size of Caps ( from the website, 0.1v - 1v ). What will be the difference?
B. Rgds
Andis
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Hi Tan,
Some more questions:
Some user claimed the performance of Burson discrete op-amp was not good (AD825 is even better) but the problem may be due to voltage supply issue. It claimed the voltage supply is at least 15v in order to optimise this op-amp to function normally. So have you checked if Promitheus DAC provide enough voltage to power the op-amp? (May be Nick can help to answer this question)
I am not technical guy, so if I need to modify the power supply of the DAC in order to change the Burson discrete op-amp, then I am not able to do it. :duh:
Have you tried different size of Caps ( from the website, 0.1v - 1v ). What will be the difference?
B. Rgds
Andis
Andis,
Nick said replacement of stock opamps with Burson is fine. I do not have problems at all and did not need to replace any caps for PS. I personally do not like the sound of AD825. Maybe the audio consulting opamps are good but I doubt it. You might look and compared them to Burson. However, I still love the sound of Burson opamps after breaking in. :thumb: :banana piano:
http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=OPAMPS
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Hi Tan
Have you tried different value of Caps ( 0.1uf - 1uf MKP across pin 4 and pin 7 as suggested ). What will be the difference?
Many Tks
Andis
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Hi Tan
Have you tried different value of Caps ( 0.1uf - 1uf MKP across pin 4 and pin 7 as suggested ). What will be the difference?
Many Tks
Andis
Andis,
Burson suggests 0.01mF which is a perfect value to bypass but you can try higher values. I do not have the high value caps in hand right now.
Tan
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Just got my dac today, and have played for some hours, well what can i say: i am actually speechless...
The Promitheus dac fitted my system like a glove, simply amazing, can hardly wait until the burn in is finished.
By the way, mine had black lid and bottom and also a green (power) and a red (lock?) leds..
Build quality was excellent, this just might be my best hifi buy ever :D :D :D
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Just got my dac today, and have played for some hours, well what can i say: i am actually speechless...
The Promitheus dac fitted my system like a glove, simply amazing, can hardly wait until the burn in is finished.
By the way, mine had black lid and bottom and also a green (power) and a red (lock?) leds..
Build quality was excellent, this just might be my best hifi buy ever :D :D :D
Congrats to you.
Mine is the first version. Does your DAC have a wooden platform underneath the pcb? If you do not mind would you post some pictures of your Promitheus DAC? Thanks in advance.
Happy listening,
Tan
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Yes, it has a wooden platform under the pcb, and also a piece of wood under the two trans.. on the dacs right side.
Will try to take some photos...
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Milenko
Good to hear you like the DAC
Tan and Andis
I check out the burson buffer posting of yours and would like to comment that our DAC allows up to +14.5Volts to -14.5 Volts. You would need to turn the potentiometer clockwise to turn up the voltage
Also the maximum voltage may not be fully regulated if your wall drops below 118Volts. To measure place the probe of the multimeter at pin 4 and pin7
Pin4 is the minus voltage
pin7 is the positive voltage
The opamp chips are fed with a double stage regulator that means its a LM317L into a BC556 pass transistor. Hence there more voltage drop than the conventional regulators but the sound is much better because it decouples the right and the left channel
Also there is another tweak i would like to tell is to adjust the voltage of the opamp. Normally we set them at 12volts. I find i like this combo best. IF you system is transparent enough, 11.5 volts the sound would be laidback full body but may lack dynamics. 12.5 volts the sound is more dynamic, thinner and 12 volts is what you hear at the moment. I like 12 volts best. Play around if you are in the state of being able to place the probe steady on the pins of the opamp. The DAC is transparent to show that every little voltage counts
CHeers
Nicholas
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Hi Nick.
Is +/- 14.5V recommend for Burson? What about 230V country?
Regards,
Mart
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I check out the burson buffer posting of yours and would like to comment that our DAC allows up to +14.5Volts to -14.5 Volts. You would need to turn the potentiometer clockwise to turn up the voltage
Also the maximum voltage may not be fully regulated if your wall drops below 118Volts. To measure place the probe of the multimeter at pin 4 and pin7
Pin4 is the minus voltage
pin7 is the positive voltage
The opamp chips are fed with a double stage regulator that means its a LM317L into a BC556 pass transistor. Hence there more voltage drop than the conventional regulators but the sound is much better because it decouples the right and the left channel
Also there is another tweak i would like to tell is to adjust the voltage of the opamp. Normally we set them at 12volts. I find i like this combo best. IF you system is transparent enough, 11.5 volts the sound would be laidback full body but may lack dynamics. 12.5 volts the sound is more dynamic, thinner and 12 volts is what you hear at the moment. I like 12 volts best. Play around if you are in the state of being able to place the probe steady on the pins of the opamp. The DAC is transparent to show that every little voltage counts
Nick,
I have steadily measured at pin4 and pin7 and see that it has 23.45VDC on the left and 22.74VDC on the right. Why the numbers are higher than your suggestion 12VDC? But the sound has body, transparent and dynamic. I set at 2dB. Any comments? Thanks.
Tan
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Tan
sorry forgot to write it should pin4 with reference to ground
and pin7 reference to ground
IN your case you would need to retune the voltage because of the burson opamp slightly different current draw hence the voltages are not equal as we set for our opamp 5534
Cheers
NIcholas
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Nick,
How do I retune to match the Burson opamp voltage with the DAC voltage? Thanks for help.
Tan
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Just got my dac today, and have played for some hours, well what can i say: i am actually speechless...
The Promitheus dac fitted my system like a glove, simply amazing, can hardly wait until the burn in is finished.
By the way, mine had black lid and bottom and also a green (power) and a red (lock?) leds..
Build quality was excellent, this just might be my best hifi buy ever :D :D :D
wow, you got your dac pretty quickly. good news. i still haven't had a chance to order one, i was in the middle of moving homes during christmas and still have too many boxes to unbox and organize before i can start enjoying audio again. did you get the silver pulse transformer upgrade? can anyone comment if there is a significant improvement by going with it?
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Anthony:
Yes, i got the silver pulse transformer upgrade. The dac sounds amazing and is getting better and better every minute. I hear details in my cds now that were drowned on my cd player which actually is not bad at all (thule spirit 150b). Heard the soundtrack from Pearl harbour today and i could literally pick out layer upon layer in the music, amazing details and still no digital hizz of anykind. It is just warm and musical with all the details. Some of the singers you can hear breathing and some f.ex. Bruce Springsteen has a much more "rusty" and natural voice than before, and...i could go on and on...simply stunning.
Tan:
Will try to post some pictures tomorrow, been busy working, listening to music, playing with my little daughter and so on.
Will like to add a big thank you to everyone who has posted in this tread which helped me to make the right decision.
Also a huge thank you to Nicholas Chua for truly making a fantastic dac at an amazing low price.
I will definately check out your pre-/power amps when it is time to upgrade again.
Sincerly:
Svein
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Hi, I'am new to this forum, have just received my dac from Nick two days ago and have started using it with my existing system....the sound from this dac was really good....it has a detailed, layered, warm and musical sound....will have to let it break in until it reaches 100hrs to see how much improvement the sound can be!....all in all its a good dac and value for money too. :thumb: :)
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Tan: sorry for the pictures delay, my whole family has been sick so....
But now we are much better :D
Here are the pictures of my Promitheus dac:
(http://www.audiocircle.com/image.php?id=13456)
(http://www.audiocircle.com/image.php?id=13457)
First time posting pictures in the forum, hope they are ok. :D
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Milenko27,
Thanks for nice pics.
I also did the same as Nick about the wooden platform underneath pcb. I will place the ebony wood underneath the PS tranny and output trannies soon. Let see how is the sound improved.
Regards,
Tan
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hey guys,
new to this forum but considering the dac. i wondered how this dac stacks up specifically with the mhdt labs constantine. could someone offer a detailed comparison. thanks
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hey guys,
new to this forum but considering the dac. i wondered how this dac stacks up specifically with the mhdt labs constantine. could someone offer a detailed comparison. thanks
IMO I have own the modded Promitheus DAC and modded MHDT Renaissance II DAC (same circuit as Paradisea with toroidal transformer PS). I would prefer the Promitheus DAC in my system with some tweaks. Good luck.
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Hi Tan,
Burson replied me that they are out of stock now. I was told by other that this Opamp was not actually made by Burson, it was orginally made by a China company but has stop the production now. Burson has bought all the remaining stocks at that time.
Not sure if it is true or not but in case there is no more Burson Opamp. Would BB627 the best alternative. What will you recommend?
Rgds
Andis
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Hi Tan,
Burson replied me that they are out of stock now. I was told by other that this Opamp was not actually made by Burson, it was orginally made by a China company but has stop the production now. Burson has bought all the remaining stocks at that time.
Not sure if it is true or not but in case there is no more Burson Opamp. Would BB627 the best alternative. What will you recommend?
Rgds
Andis
Andis,
Sorry to hear that bad news. Anyways you should give a try with BB627 or may be audiocom AD825 which sold by Reference Audio Mods in California. I might try Audiocom AD825 to compare with Burson Discrete Opamps. Here is the link:
http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=OPAMPS
Good luck,
Tan
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andis
i have 1 pair left of this burson buffer
email me if you need this pair
should be about the same price perhaps a bit more to cover the shipping
sad to hear that burson can't source their opamp anymore
will look into an discrete opamp
cheers
nicholas
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Hi Tan,
Burson replied me that they are out of stock now. I was told by other that this Opamp was not actually made by Burson, it was orginally made by a China company but has stop the production now. Burson has bought all the remaining stocks at that time.
Not sure if it is true or not but in case there is no more Burson Opamp. Would BB627 the best alternative. What will you recommend?
Rgds
Andis
I'm not so sure of this, from talking to the owners of Burson about this well over a year ago. It was explained too me. That they indeed make the op amps in house. There was a big skirmish from a Chinese company that they used to out source the work when the op amps became very popular.
That company started manufacturing and selling the op amps on the side without their permission. In the end they were able to stop the OEM company from copycatting their design and under selling them.
Burson is a small company, they maybe out temporarily. Hopefully their not out of the op amps permanently.
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Just to inform every one that Affordable Audio has come up with their March Issue
And our DAC is reviewed in this March Issue
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Hi Nic,
How do you compare the Burson Opamp with your stock 5534?
In case I want the Burson Opamp, can you test for me which value of the bypass cap give the best performance and solder it for me. (Will send you an email when confirm)
Tks & Rgds
Andis
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Hi Nic,
How do you compare the Burson Opamp with your stock 5534?
In case I want the Burson Opamp, can you test for me which value of the bypass cap give the best performance and solder it for me. (Will send you an email when confirm)
Tks & Rgds
Andis
Andis,
Believe me Burson opamps are way better than the stock NE5534 which I never looked back. You just go ahead and grab them. For the bypass I use the Vishay MKP 1837 0.01mF/160V which is the best bypass cap according to the cap test of Humble Homemade Hifi (http://www.humblehomemadehifi.com/Cap.html). Nick has never shown me to adjust the Burson from 25V to 12V like he suggested for the DAC opamp. But I still love the sound of my modded DAC right now.
Tan
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tan
i posted before on how to tune the voltage
I check out the burson buffer posting of yours and would like to comment that our DAC allows up to +14.5Volts to -14.5 Volts. You would need to turn the potentiometer clockwise to turn up the voltage
Also the maximum voltage may not be fully regulated if your wall drops below 118Volts. To measure place the probe of the multimeter at pin 4 and pin7
Pin4 is the minus voltage
pin7 is the positive voltage
to make it clearer. the potentiometer is the blue color box with a screw on the top. This potentiometer is on the DAC board and NOT on the burson
Make sure you measure the pin4 and pin7 with reference to ground.
hope this helps.
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Nick,
I got it. But somehow I could not adjust equally pin7 between two channels of Burson Opamps. However, I like the sound in between 11.30V to 12.5VDC. Thanks for your help.
Tan
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Hi Nic,
Just a suggestion! It is on the premise that many audio junkies use more than 2 digital sources connected to produce music.
It’ll be great, if there’s a single box Promitheus DAC in monaural tubed design, residing in the two scooped out areas of a block of Merbau.
Each channel's circuit can've component locations exactly replicated, and the surrounding wooden walls pasted with copper tape. It can’ve a choice of inputs; coaxial, XLR, USB and optical, as per customer choice.
This unit can’ve phase inverter and mute features and external 2-box reference power supplies, if the customer wants. It’ll be a killer if all this can happen within $1500. Guess, the Merbau block’ll take most of the cost.
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After a week of running the DAC with my second system, I connected it to my main system about a week ago and ran it through its paces. My audio system consists of:
1. Eastern Electric Minimax CD player (used both as CD player and as transport)
2. Monarchy Audio DIP
3. Promitheus Audio non-OS DAC (factory-installed upgrades: silver upgrade, AES/EBU input, Burson Audio Op-amps, XLR output)
4. Promitheus Audio TVC & Balanced Stepped Attenuator [using 4-section stepped attenuator, XLR in/ out]
5. Aleph 30 clone with both single-ended and balanced inputs (made by Tim Rawson)
6. Promitheus Audio solid-state OPTs
7. Mission 752F speakers
Three impressions stand out using a fully balanced connection throughout:
a) Top-to-bottom cohesion and a sense of continuousness about the music. No part of the audio spectrum stands out, and rather than focusing on brilliant highs, smooth mids, etc., what I hear is the sheer flow and momentum of music. I've tried this out with both jazz and classical CDs.
b) Overall cohesion doesn't mean that pace, rhythm and timing are sacrificed in any way. Listening to Paul Galbraith's guitar transcriptions of Bach's Sonatas and Partitas, fast passages are conveyed with absolute integrity.
c) It's easy to follow complex orchestration without losing the sense of the whole: i.e., the DAC is not overly analytical, but none the less does not blur things together. I've been listening to both the Mahler's symphony #2 (Otto Klemper's 1963 version with the Philharmonia orchestra) and Shostakovich's symphony #7 (Leonard Bernstein with the New York Philharmonic), and the sense of scale and drama of the music is something to hear.
General Observations:
1. Overall the sound is better when I run the SPDIF out from the CD player to the Monarchy Audio DIP and use the AES/EBU out from the DIP to the AES/EBU input of the Promitheus Audio DAC. Also the XLR output is marginally better than the RCA output, in terms of image stability and bass. I would say that people should request these as standard upgrades when ordering, along with the Burson Audio op-amps.
2. No doubt, the Promitheus Audio blows out of the water both the DAC built into the Minimax CD player, which by the way has been highly praised by reviewers in 6moons.com, DAGOGO, etc., not to mention my other non-OS DAC the Shek D2, which seemed very satisfactory until I got the Promitheus Audio DAC.
3. I don't particularly like equipment that is 'ruthlessly revealing' etc., it just suggests that the item in question is a bit cold and analytical. So I won't say the Promitheus Audio DAC is 'ruthlessly revealing'; it just makes music enjoyable. I'm drawn into the music and have found myself going with the flow. This is really good stuff.
Congratulations to Nicholas for another stand-out piece. Now, I only wish I had ordered the Promitheus Audio TVC with balanced connections. My Ref 3 (2 silver RCA inputs, outputs) is for sale and I'm already saving for a Ref 4 or maybe even the C-core TVC.
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Hi you all,
Nicholas invites me to share with the forum my impressions about his DAC.
I have it about 2 weeks with Burson's opamps. So, i never heard it with other opamps.
I'm not telling you about its dynamics, sound stage, resolution etc.
My approach is diferent:
Can I, well seated, after warm up the DAC and myself (a good scotch/irish wiskey or a good portuguese red) and my mind cleaned, float?
If yes it is a good piece of gear. And this is the case? YES.
Give the DAC all the current it needs, place it on 5 cm's height natural cork plate marry it with same league pieces and i'm sure you can also float.
Thanks to Nicholas.
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Calling all end usrs of the DAC ,
I received the DAC about a week ago and would like to share my experiences.
Straight out of the box, DAC sound analogue and refined but I felt there is not enough transparency and slightly veiled. There is a very sweet mid but lacking in high . The cymbals sound muted. There is not enough drive and rhythm to the music and do not felt a compulsion to tap my feet. I felt sleepy .
I did the following to try and overcome the problem:
1. Change to silver power cord from Nic
2. place the DAC on the aluminum /ceramic support – may be the Ceraball – not sure
3. clean up the contacts for the op amp and the jumper for voltage selection with Philips contact cleaner and apply the Nanotec copper contact enhancer. The last has the greatest effect and increase the transparency quite a bit
4. Change the internal jumper to 4 V setting. This increase the drive and makes it more dynamic.
I hope to find out from other end users , the difference in sound between the stock Philip op amp and the Burson discrete op amp .
Cheers
Kp93300
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I liked the dac when it was working.After numerous emails to Nicholas in six weeks and being told there was a new dac board on the way,nothing yet.Very frustrating.
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I liked the dac when it was working.After numerous emails to Nicholas in six weeks and being told there was a new dac board on the way,nothing yet.Very frustrating.
Did Nicholas say he was sending you a brand new replacement, or that there was an entirely new board design on the way?
By the way, anybody heard from Nicholas lately? He is probably extremely busy, and currently seems incommunicado...
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I ordered a wholesystem from Nick in novemeber and am still waiting for delivery. He told me that its alomost done a few weeks ago, but I haven't been able to reach him since........ :?
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i guess now is not the time to ask what the average lead time is for a dac..
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Hello to everybody.Nicholas sent me an email on the 21/4/08 saying that the dac board has just been posted.He is sending me a dac board for me to fit myself and I will return the faulty one.I find Nicholas very courteous and helpful,I know he takes a while to answer emails.Maybe he needs a technically minded secretary to ease his workload.His question about a 6db gain option for his TVC would be worthwhile,but how would you know if you need the extra gain until you have the TVC in your own system.I have a Meridian 588 CDP as my source and 4 power amps(2 valve,2 solid state) and find the gain too low.I also have a Audio Synthesis Passion (passive pre) and don't have the same low gain issue.
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Nick,
I got it. But somehow I could not adjust equally pin7 between two channels of Burson Opamps. However, I like the sound in between 11.30V to 12.5VDC. Thanks for your help.
Tan
Hi Tan,
Would you be willing to post a pic of the internals of your Promi DAC, showing those Bursons in there? That would be really cool to see (but only if you have the time of course)...
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Hi everyone,
I just received my DAC from Nic a few days ago, its the latest version, silver pulse, silver RCA. Out of box, it sounded wonderful especially the bass but treble a bit coarse/hard - need time to burn in more. My only complaint so far is in the LEDs (looks only) - too big/bright and colour choice. It was RED and GREEN. I changed them to smaller ORANGE and BLUE and added resistors to dim them.
Now for my question : how and where to place the feet/footings under the DAC to bring out its best?
Since the DAC comes without any feet whatsoever, can anyone share their experience/experiment on the subject? Cones, which is better wood or metal? Hard, soft or heavy/light wood? Orientation - pointed tip up or down? Location of cones? Placing them directly under the 3 trans? Thank you
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Hi everyone,
I just received my DAC from Nic a few days ago, its the latest version, silver pulse, silver RCA. Out of box, it sounded wonderful especially the bass but treble a bit coarse/hard - need time to burn in more. My only complaint so far is in the LEDs (looks only) - too big/bright and colour choice. It was RED and GREEN. I changed them to smaller ORANGE and BLUE and added resistors to dim them.
Now for my question : how and where to place the feet/footings under the DAC to bring out its best?
Since the DAC comes without any feet whatsoever, can anyone share their experience/experiment on the subject? Cones, which is better wood or metal? Hard, soft or heavy/light wood? Orientation - pointed tip up or down? Location of cones? Placing them directly under the 3 trans? Thank you
Hi Dexsam,
I put my first version DAC on a Black Derin Acetal platform which has the wooden cones came with the DAC (two in the front and one in the back). It sounds excellent to me.
You should try some of your preferences you like and adjust them with your own ears since the DAC is set up in your own system. Good luck.
Tan.
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I've had my promi dac for almost a year and really love it. In last 3-4 months sometimes when I turned on my gear the DAC wouldn't have sound - the red led light was off. If I unplugged and re-plugged or flipped the toggle switch on the back the sound would come back. I asked Nik and he said it was a quirk of the machine and implied that it wouldn't get worse. However, as time passed, this problem became more frequent. In the last two weeks, the dac cuts out almost every half-hour. There's a brief fizzling, the sound quickly fades, its silent for varying lengths of time, then it comes back. The cycle can take 30 seconds to 2 minutes. I'm wondering if anyone has had a similar experience or has suggestions what might be going on.
I've e-mailed Nik a couple times about this but haven't received a response. I'm sure he'll get back to me but he's busy and his responses have been slow in coming so I thought I'd see if anyone here might have some ideas about what I might try to fix the problem.
Thanks,
Bob
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Did you ever receive your separate USB module for your DAC? How is your DAC connected - coax, USB, etc?
Also, is your DAC a standard one (with the chip op-amp outputs), or does it contain the discrete Burson op-amp upgrade?
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Hi,
I received the USB module. The Dac is connected by RCA coax. There wasn't a Burson op-amp upgrade at the time I purchased so its the standard op amp.
Thanks,
Bob
Did you ever receive your separate USB module for your DAC? How is your DAC connected - coax, USB, etc?
Also, is your DAC a standard one (with the chip op-amp outputs), or does it contain the discrete Burson op-amp upgrade?
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Nicholas answered my email and offered to replace the board. Before he responded I decided to swap out the 75 ohm ic I'd been using. (I had actually been switching between two 75 ohm ics.) I used an analogue ic and so far the sound hasn't cut out on me. Nick said he's used 75 ohm without incident. So far so good. Has anyone else experienced this problem? I would like to be able to use the new 75 ohm ic I purchased from Burt Grover but I guess I'll have to live without it. I'll let you know if I find that its definitely the 75 ohm ics.
bob
Hi,
I received the USB module. The Dac is connected by RCA coax. There wasn't a Burson op-amp upgrade at the time I purchased so its the standard op amp.
Thanks,
Bob
Did you ever receive your separate USB module for your DAC? How is your DAC connected - coax, USB, etc?
Also, is your DAC a standard one (with the chip op-amp outputs), or does it contain the discrete Burson op-amp upgrade?
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Nicholas answered my email and offered to replace the board. Before he responded I decided to swap out the 75 ohm ic I'd been using. (I had actually been switching between two 75 ohm ics.) I used an analogue ic and so far the sound hasn't cut out on me. Nick said he's used 75 ohm without incident. So far so good. Has anyone else experienced this problem? I would like to be able to use the new 75 ohm ic I purchased from Burt Grover but I guess I'll have to live without it. I'll let you know if I find that its definitely the 75 ohm ics.
bob
Glad you got an email response Bob - many are finding it very difficult to reach Nick lately. :scratch:
Interesting that using the proper 75 ohm cable would be a problem... could this mean that the digital input (pulse) transformers Nick is using, are not 75 ohm? Does your DAC have the silver pulse transformer upgrade?
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I have own the first version of Promitheus DAC with silver pulse transformer that Nick sent to me for upgrading and I had upgraded myself the Burson Discrete opamps. I have never had issues or whatsoever that stop playing my musics since then. This is an excellent DAC I have ever had to play in my system. It is very balanced and musical. :thumb:
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I believe it does have the silver pulse upgrade. When I bought it, it had all the bells and whistles available from Nick at the time and I think the silver pulse transformer was one of the offerings.
Bob
Nicholas answered my email and offered to replace the board. Before he responded I decided to swap out the 75 ohm ic I'd been using. (I had actually been switching between two 75 ohm ics.) I used an analogue ic and so far the sound hasn't cut out on me. Nick said he's used 75 ohm without incident. So far so good. Has anyone else experienced this problem? I would like to be able to use the new 75 ohm ic I purchased from Burt Grover but I guess I'll have to live without it. I'll let you know if I find that its definitely the 75 ohm ics.
bob
Glad you got an email response Bob - many are finding it very difficult to reach Nick lately. :scratch:
Interesting that using the proper 75 ohm cable would be a problem... could this mean that the digital input (pulse) transformers Nick is using, are not 75 ohm? Does your DAC have the silver pulse transformer upgrade?
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Hi everyone,
After using the DAC with stock NE5534 op amp, for a month, I ordered the Burson discrete op amps from Australia and received them yesterday. Today (Sat), I tried bending the leads (extra long, new design according to Burson) in shape to suit the DIP8 pins, see picture below, thinking that I could just insert into socket and switch back to ICs anytime.
(http://farm4.static.flickr.com/3179/2597867104_cec592832f_o.jpg)
After many tries, I gave up inserting the Bursons into the IC socket. :duh: So, I removed the IC socket and directly solder the Burson leads onto the PCB. Finally, its done - see below. You will notice that the Bursons are inverted - I dont know if its gonna be a problem. Putting it the other way would obstruct the jumpers (for gain adj). Everything fits well inside and the cover can be closed with a 5 mm gap between Bursons and cover.
(http://farm4.static.flickr.com/3199/2597022267_d0ca0fcb9c_o.jpg)
Now for the setting of voltage, I have a problem here. Measuring from ground (G, circled & arrow), the voltages at pins 4 and 7 are measured and adjusted as instructed by Nic. Problem is, I could not get the SAME voltage for the L & R sides. The R side is always higher. If I set the L side to say, +/-12V, the L reading is +12.04V and -12.08V; but the R side reading is +14.38 and -15.02V, such is the difference. If I set the R side to +/-12V, the L side is measured at only 10~11V. The 2 voltage adj screws are for positive and negative supplies and the L & R sides should get from the SAME supply, and hence the SAME voltage, but why the difference? Can Nic please explain here?
Another thing - I measured the output (pin 6) with respect to ground and it is a high +1.14V for L; and +0.61V for R. I know, this dc voltage is blocked by the output trans, but shouldn't the output be near zero or in the millivolt range at most. On IC op amps we have the offset null adj. Can Nic explain how to set to zero?
Despite above setback, the sound is there (and good sounding too), no noise etc, at first burning in, but the Bursons runs quite warm after sometime - the pcb is in the region of 50deg C, which I think is too high so I switched it off until I get more assurance. Anyone has the same experience and would like to share/comment/advise here?
Thanks in advance.
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Dexsam, I am very interested in your modification experiment using the Burson Discrete
OpAmps. Are you going to solder a "foil capacitor across the power intake (V+ and V-) of
the Discrete Op-Amp", as suggested on the Burson website (http://www.bursonaudio.com/Burson_Discrete_Opamp_101.htm)?
Please keep us posted on your results :)
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Has anyone encountered a loud hum (can be heard even when the amp volume is at low levels) with the Promethius DAC? I have contact Nicholas and I am sure he will get back soon with an answer but was just curious if anyone else had had this problem and if they solved it.
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Now for the setting of voltage, I have a problem here. Measuring from ground (G, circled & arrow), the voltages at pins 4 and 7 are measured and adjusted as instructed by Nic. Problem is, I could not get the SAME voltage for the L & R sides. The R side is always higher. If I set the L side to say, +/-12V, the L reading is +12.04V and -12.08V; but the R side reading is +14.38 and -15.02V, such is the difference. If I set the R side to +/-12V, the L side is measured at only 10~11V. The 2 voltage adj screws are for positive and negative supplies and the L & R sides should get from the SAME supply, and hence the SAME voltage, but why the difference? Can Nic please explain here?
I have a same problems with big different output voltages of the Burson Discrete opamps between two channels. However, you should adjust based on your sonic tastes that come out of the DAC to your whole system. I have a first version DAC and Burson opamps with ground wires hang out. Your problem of getting warm as not usual happens to mine (running cool!!!). I guess you need to bypass pin4 and pin7 as Burson Audio suggested.
Good luck and happy listening,
Tan
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Has anyone encountered a loud hum (can be heard even when the amp volume is at low levels) with the Promethius DAC? I have contact Nicholas and I am sure he will get back soon with an answer but was just curious if anyone else had had this problem and if they solved it.
This sounds like unsual to me. Did you change or remove anything?
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I only received it yesterday. I also checked to make sure it wasn't the amp, cables, or RF, but the noise is clearly coming from the DAC via the line out irrespective if there is a digital signal coming in or not. To be honest I was hoping for some easy solution so that the item will not have to go back.
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Dear all,
After posting the problems faced after the direct replacement of NE5534 with Bursons, I receive no replies from Nic, so I contacted Burson. And they told me this: optimal voltage supply is +/- 15V, and that the capacitors on board the DAC are insufficient (in value). Hence recalling from somewhere, that Nic's design dont allow such high voltage and the voltage regulation would be poor because the Bursons draw a much higher current that the NE5534 it replaces, I decided to ADD a completely new power supply to cater for Bursons. The Burson technical supported the idea saying the inadequate power supply is the cause of the 'not outstanding' bass that I complained as quality bass is their strength.
So, in went a new mains transformer with output 15V-0-15V, bridge rectifier, a pair of 2200uF capacitors, bypass capacitors, 15V+/- IC regulators x 4, followed by 4 x 470uF capacitors and at the Bursons end coupled the V+/- (pin 4, 7) with foil capacitors 0.1uF x 4 - maybe a bit overkill but it worked(see picture below - the new trans and voltage regulators on bottom left; yellow cylinders are foil caps).
(http://farm4.static.flickr.com/3016/2627286821_ea03862ba0_o.jpg)
Now I have no complaints on the sound, and its only running for a couple hours. Everything is there, the bass is full, solid, the air in voices and cymbals, separation of instruments very clear - all in so much better than IC op amps. My best investment so far - A$80 for the pair of Bursons and US$25 for the DIY power supply. The only "problem" left is this : there is still a dc offset at the output and the Bursons run hot still - at about 53deg C steady state. Burson technical say they run in class A and some heat is produced but I didnt think it is that hot! So far happy with the upgrade, next would be just replacing the cheap electrolytics on my new power supply with Blackgate capacitors.
Tanchiro - i am surprised that your Bursons run cool - I actually measured the temp and it is the hottest component on the DAC.
Regards.
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Tanchiro - i am surprised that your Bursons run cool - I actually measured the temp and it is the hottest component on the DAC.
Hi Dexsam,
I am glad that you have just done an excellent modification. So that means you have eliminated all original power supply to use with your new one. Is this any link that you can provide us to try out a new power supply for the Promitheus DAC?
My Burson Discrete opamps run not too cool (sorry for the mistake) but they are little warm but not hot to too hot. I thought that would be totally normal for a component. However, I still love the balanced sound of my Promitheus DAC compared to my Altmann Attraction DAC (8:10 ratio to my ears).
It is good to know another modified version for the DAC from you. Keep a good work and share with us it would be appreciated.
Many thanks,
Tan
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I only received it yesterday. I also checked to make sure it wasn't the amp, cables, or RF, but the noise is clearly coming from the DAC via the line out irrespective if there is a digital signal coming in or not. To be honest I was hoping for some easy solution so that the item will not have to go back.
Double check your digital cable connection from the source to the DAC. I had a problem once when friend of mine he did for me a DIY silver RCA digital cable and had a loud hum on one channel when I switched to RCA from BNC. First I thought the DIY cable lacked of insulation but yesterday I reconnected to the same connector the hum was not there. It is hard to explain this matter but you need to check step by step. Good luck.
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Hi Tan,
What I did was, ADD a new power supply which outputs separately two +15V and two -15V (hence the four IC regulators) actually you can use 2 regulators giving one +15v and one -15V with the L & R channels sharing the power supply. In my case there is no sharing (for better separation, I guess), afterall an IC regulator (LM7815 for positive, LM7915 for negative) cost under $1 each. Then I disconnect the Bursons power supply leads (pin 4 for negative, pin 7 for positive) from the DAC main pcb, and connect to the newly built power supply. The original power supply from the DAC main pcb is left intact, as it maybe routed to power other parts of the circuit of the DAC. Now that the Bursons got separate power supply means there is less load for the original power supply - an added advantage. Of course, not forgetting the Ground (0V) of the power supply is connected to the main pcb ground. My new transformers have 15V-0-15V (AC) outputs hence giving a rectified but unregulated +/-21Volts DC, more than enough voltage for the regulators to bring down to the required +/-15V.
I just use the standard regulated power supply circuit from the application notes of LM7815/7915 IC regulators (available online)to construct my power supply, nothing fancy; only thing I over design a little on the smoothing capacitors. Some say LM317 regulators are better, but the LM78XX is good enough and very simple, just one chip.
I am surprised to hear that some using the DAC had 'hum/noise' problems - maybe ground loop issue in the connections. Mine had no noise nor hum - dead quiet, before and after adding new power supply.
Thanks for reading.
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...I receive no replies from Nic, so I contacted Burson. And they told me this: optimal voltage supply is +/- 15V, and that the capacitors on board the DAC are insufficient (in value)... Nic's design dont allow such high voltage and the voltage regulation would be poor because the Bursons draw a much higher current that the NE5534 it replaces... Burson technical supported the idea saying the inadequate power supply is the cause of the 'not outstanding' bass that I complained as quality bass is their strength...
Dexam I'm glad you were able to build such a nice quality power supply fix for this situation - I wish that I had your skills.
If the stock Promitheus DAC has unsuitably low voltage and insufficient capacitors for the direct Burson mod, this unfortunately might mean that probably users of the DAC who purchased the Burson upgrade directly from Burson and installed it themselves, may have their Burson product performing more poorly than it should, as a result - especially as you reported, in the bass.
Hope you can also fix the further problems, regarding DC offset and heat...
Edit: Nick has already commented later in this thread, about how to fix...
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Hi Tan,
What I did was, ADD a new power supply which outputs separately two +15V and two -15V (hence the four IC regulators) actually you can use 2 regulators giving one +15v and one -15V with the L & R channels sharing the power supply. In my case there is no sharing (for better separation, I guess), afterall an IC regulator (LM7815 for positive, LM7915 for negative) cost under $1 each. Then I disconnect the Bursons power supply leads (pin 4 for negative, pin 7 for positive) from the DAC main pcb, and connect to the newly built power supply. The original power supply from the DAC main pcb is left intact, as it maybe routed to power other parts of the circuit of the DAC. Now that the Bursons got separate power supply means there is less load for the original power supply - an added advantage. Of course, not forgetting the Ground (0V) of the power supply is connected to the main pcb ground. My new transformers have 15V-0-15V (AC) outputs hence giving a rectified but unregulated +/-21Volts DC, more than enough voltage for the regulators to bring down to the required +/-15V.
I just use the standard regulated power supply circuit from the application notes of LM7815/7915 IC regulators (available online)to construct my power supply, nothing fancy; only thing I over design a little on the smoothing capacitors. Some say LM317 regulators are better, but the LM78XX is good enough and very simple, just one chip.
I am surprised to hear that some using the DAC had 'hum/noise' problems - maybe ground loop issue in the connections. Mine had no noise nor hum - dead quiet, before and after adding new power supply.
Thanks for reading.
Dexsam,
Thanks for sharing the modification you did to your DAC by building the Burson opamp's owned PS. It is an excellent idea IMO. But this modification might be overkill in my system since I have enough everything like I said balanced sound that I have never heard. Your DAC is a new version one which is differently built by Nick I guess. I got and inserted the Burson opamps since day one and did not have any problem whatsoever til now.
It would be nice from you if you report later how does the sound change in your system after installing Burson opamp's PS.
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Actually on our dac board, the power supply for the opamp is made much more stringent due to the 5534 lower PSRR ratio.
Our power transformer is has 2 segments, 1 set of wires is for the digital (3cables braided) and 1 set of wires for analague (opamp onlY, 3 wires braided). This is 20va and is 15-0-15 in balanced winding for noise cancellation. So its 21 volts before the regulator too.
It feeds a lm317L series which has better PSRR than the stock lm317 and then after that each power supply feeds a dedicated discreet regulator. Normally after the discreet regulator there is not much left of voltage headroom for regulation
The power supply before the discrete regulator can be made for +-15volts with a problem. The Discreet stage can also be made to output +-15 voltage but you would require to change the 180 ohm resistor to a lower value like 50 to 100ohms. The 2nd stage may require a 120volt main supply. On its own the highest voltage the dac can be set is 13.8volts which is more than adequate headroom for the 5534 but not for the burson.
Again the double stage regulation is a must for lower PSRR 5534.
Also the burson offset voltage depends on voltage and i am not sure they can be trim. The transformer likes to see some offset to linearize the core 20mv to 30mv would be the a good range for sonics reasons. 80mV is not that bad. DO note i prefer the sound with some offset, sound better as the dc forces the core to run in a more linear BH curve
When we install burson, we just swap the 180ohm resistor near the opamp to 50ohms then it would regulated higher.
The burson needs higher to work with because of the transistors and the jfets they used
dexsam
did not get your email. Could have enter our spam filter
COuld have also miss this email, during the last 4 months we are shortage of manpower, we were trim to half our manpower and i was basically doing all the process to cover and make up for it
Things are better now as we are back to full manpower
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The Discreet stage can also be made to output +-15 voltage but you would require to change the 180 ohm resistor to a lower value like 50 to 100ohms.
Hi Nick,
From your suggestion in the past, I trimmed blue pot on PCB and got around 14.9 V +/- stable.
Yes, I waited about 30 minutes and repeated measuring a result. Nothing was wrong since that day
(I'm not sure, may be I live in 220V. country)
Do I still need to change resistor as your recommended or just change a resistor
with return blue pot to 12V. position?
Hi dexsam,
Which capacitors I need to change for dealing with Burson and what's value that they recommend?
Funny part start again....BTW, my burson is the old version, like Tan uses.
Regards,
Mart
:)
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Mart
If you can get 14.9Volts stable then you don't have to change the resistor.
how much the regulator can regulate depends on your mains voltage
here in my office we are 205volts, and at home 220volts. Malaysia specs their voltage at 240voltages
the burson really looks much different that what i have. Can't comment how it would effect our boards
also from what i did to help out a local customer we bought the fame 10nF MKP Roderstein stuff and bypass across +v supply to ground, -v supply to ground and +V supply to -Vsupply. Really improves the burson quite a far bit. ITs hard to solder them though
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also from what i did to help out a local customer we bought the fame 10nF MKP Roderstein stuff and bypass across +v supply to ground, -v supply to ground and +V supply to -Vsupply. Really improves the burson quite a far bit. ITs hard to solder them though
Nick,
Are they little square turquoise blue colors (Vishay 1837 MKPs?)? They are exceptionally excellent to bypass the Burson Discrete opamps and sound good too. I got the stable voltage between 11.30 to 12.30 VDC (pin4 and pin7 regarding to ground 0VDC) as you told me to adjust the other days but the Burson run warm would that be normal?
Analomart,
Do your Burson run warm or hot? In Fountain Valley (Southern California-USA) I always have 118-120V.
Many thanks,
Tan
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Burson's Mr Jack advises me to flip over the discrete op amps so that the heat trapped under the pcb can dissipate easily. So I did exactly that and the Burson discretes now sit the right side up (see photo) and everything else remain the same.
(http://farm4.static.flickr.com/3070/2630721887_20eaf91ddd_o.jpg)
I realised Nic's double stage regulator could not raise the voltage beyond the 13.8V level.
On the output dc offset, Nic explanation is plausible and I only wish I could adjust it. BTW your figure of 20mV to 80mV should be positive or negative or doesn't matter? Trouble is, I am getting in the region of 500mV and I am afraid the constant magnetising of the transformer core will affect the sound. The bursons have no provision for offset null as in normal IC op amps since pins 1 and 5 are not used. So how do we adjust the offset then? By adjusting the V+ and V- supplies to do the balancing act?
On bypass caps, bursons recomend from 0.1 to 1uF, I used 0.1uF. Nic says 10nF MKP which is 0.01uF and they sound very good according to him. Where can I buy those 10nF MKP?
Some of you have different (earlier) Bursons - I cant imagine, can you post the photo? Thanks
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The offset does not matter whether positive or negative but if its 500mv then its way too high and like you say it would magnetize the core. You might want to fix this quickly. I believe the heat is cause because of the high offset driving the core. and would damage the burson if this continues. The transformer would probably take a longer time to be magnetize. As there is an airgap
You have pretty much isolate the burson from our board except for the loading/gain resistors and have even done a separate power supply.
Is the offset postive or negative? if its negative you would want to increase the positive voltage to offset it and vice versa.
Without the offset capability of the opamp, the best bet is to get in touch with burson if the increase in supply voltage does not help.
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Some of you have different (earlier) Bursons - I cant imagine, can you post the photo? Thanks
Dexsam,
I got the early version of Burson opamps with Vishay 0.01uF 1837 MKP and here are the pictures (sorry for not enough clarity!!!)
(http://www.audiocircle.com/image.php?id=15087)
(http://www.audiocircle.com/image.php?id=15086)
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Hi Tanchiro58,
I have around 210V in the day and around 230 -240 V at night and
It's just warm around opamp area, eventhough I leave DAC on 24 hours.
My Burson opamp should be as same as Tanchiro's except
mine still in white copper case. I also use my old stock, MIT o.47 uf
for bypassing leg 4 and 7 without comparing result with other values.
I will try to change resistor as nick recommend cause it should be optimal for circuit
Mart
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I will try to change resistor as nick recommend cause it should be optimal for circuit
Mart
Mart,
Get either Riken or AN tantalum resistors which will sound extraordinarily beautiful!!! I will replace them soon.
Tan
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Tan, nice pictures you have there. I notice a few differences, maybe Nic can eloborate. Your DAC board looks like very close to the wood base (touching?), there's an air gap about 10mm in mine as the pcb sits on studbolts. The output to the trans is twisted pair of cables (black) whereas in mine, its single strand solid core copper wire run parallel, no twisting. The Bursons are essentially the same, only the lead out wires are different and looks like you inserted them into the IC sockets? Can the top lid be put on with the Burson in place? I notice cut pieces of black foam stuck to the top of the electrolytic caps, what are those?
For me, I will be changing the power supply to variable type using LM317/337 in place of the LM7815/7915 and individually adjust the supply rails to the Bursons to achieve the near zero dc offset following Nic advice. Will check out those tantalum caps Tan mentioned. Cheers.
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Tan, nice pictures you have there. I notice a few differences, maybe Nic can eloborate. Your DAC board looks like very close to the wood base (touching?), there's an air gap about 10mm in mine as the pcb sits on studbolts. The output to the trans is twisted pair of cables (black) whereas in mine, its single strand solid core copper wire run parallel, no twisting. The Bursons are essentially the same, only the lead out wires are different and looks like you inserted them into the IC sockets? Can the top lid be put on with the Burson in place? I notice cut pieces of black foam stuck to the top of the electrolytic caps, what are those?
For me, I will be changing the power supply to variable type using LM317/337 in place of the LM7815/7915 and individually adjust the supply rails to the Bursons to achieve the near zero dc offset following Nic advice. Will check out those tantalum caps Tan mentioned. Cheers.
Dexsam,
When I got the DAC it was nothing except PCB board, transformers and other components. Since I believe spruce board (pine wood) helps a lot in preventing vibration especially those components on the pcb I modified the Promitheus DAC based on Altmann Attraction DAC model (I own too). I also padded some of black hole pads on every capacitors and chips once again preventing the micro-vibration. I added underneath the output transformers with two pieces of ebony wood too. I also replaced and twisted all the wires of the stock DAC with OFC silver plated wires that I got from my friend. That is why the reason I said about the comparison between Promitheus and Attraction DACs.
Yes, the Burson opamps in my DAC seat on the sockets that Nick gave me the option of swapping different opamps around. Therefore, I absolutely love the sound of my DAC now. I might not need to replace the resistors as Nick suggested since it might change the sound I have right now. Besides the output voltages by the opamps are stable in my DAC.
Tan
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Hi Nick,
Can you show exact picture where 180 Ohm resister located? I found 2 sections on board.
BTW, I measured +/- V. again last night. Voltage dropped from 15.3x to 14.3x stable when
it has burson op-amp loaded. And I found that regulator from both analog and digital section is quite hot,
very hot in digital section. I could not touch it more than 5 seconds. Is this normal?
But Dac is work just find...clean, nice detail and full body with music flows.
Mart, :D
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Hi Nick,
Can you show exact picture where 180 Ohm resister located? I found 2 sections on board.
BTW, I measured +/- V. again last night. Voltage dropped from 15.3x to 14.3x stable when
it has burson op-amp loaded. And I found that regulator from both analog and digital section is quite hot,
very hot in digital section. I could not touch it more than 5 seconds. Is this normal?
But Dac is work just find...clean, nice detail and full body with music flows.
Mart, :D
Mart,
Voltage regulator is always very warm to hot hence it is often attached with heat sink. My DAC sounds just like yours. :thumb: :singing:
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My DAC produces a hum in my speakers. Not loud enough to interfere with the music but audible when the volume is turned up (from about 9 o'clock) with just the DAC connected to the amp. Nick suggested that I play around with different placement of the DAC but it didn't help. Has anybody has any experience on this matter?
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I have the same hum. I asked about it too. Nicholas suggested I try different gain settings, but, of course that doesn't solve the problem. It you increase the gain, it just means you hear the hum at a lower volume setting and vice versa - same relative volume. I'm guessing it's just part of the design. Before I got the DAC and was using the TVC only, it was dead quiet at any setting. But I would like to know if you and I are the only ones getting a hum.
Thanks!
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I have the same problem with the first dac I bought.After five months of constant communication with Nicholas , he sent me a new unit and it hums as well.The hum is actually worse than the original unit.I have given the original to unit to a specialist electronics engineer (audio) to find and fix the problem.
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Sixteen pages of discussion about the dac, and now this comes up.
Nicholas quoted me 2-3 weeks for delivery, it's been 7 without a word.
He hasn't responded to any of my emails since I paid, not even to confirm that order, or a further order of
a pair of interconnects a few weeks later. Now we hear there is a problem with the dac. And since elb's
replacement was actually worse, he may not even know where the fault lies.
I don't want to be critical, but I'm not happy.
Are hifihy, dainapoo, and elb just the unlucky ones? Or are there more of you out there?
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As I posted in a separate thread, I have also had a replacement as the first one had a loud hum, but this one has a different problem to the hum in that the sound is only coming through the right channel and the left channel has white noise.
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I had the latest version of the Dac that I sold for other reasons but it was dead quiet.Also in defense of the bad press Nick is receiving lately I have bought several items from him and although wait times are somewhat long he never failed to respond to emails.Paul
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Agree with you PTC, I have always found Nicholas to be polite and helpful and he does respond to emails even if it can take a little time. Sometimes emails get caught in his spam folder so it can be worth resending any emails for which you haven't received a reply within a week or so. In regards to my second DAC I beleive that it is likely to be a fault caused in transport as Nicholas has said that he tested the DAC before shipping and it worked fine.
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Finally got this Sun discrete Opamp from Audio-gd
http://www.audio-gd.com/enweb/pro/diy/OPA.htm
They claimed this is a revised version and no need to solder anymore bypass cap. Cant confirm if this is same as Burson but very similar with much cheaper price. Unfortunately, the new size of this Opamp is too large and cant insert directly to the IC socket, so not able to give any comments yet.
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I just been a lucky owner of this DAC. I am living Norway and is the 3th owner of it. I have been told by the seller that it is the last version and bought early this year. However I am not sure if the pulse
trafo is the silver one how can I check that? The one I got have the PCB and output trafo placed on wood.
At the moment I am looking forward to replace the output NE5234 with
the Burson modules.hey are will be fit in tomorrow and later on get their own dual PSU for the best working condition.
So fare I have just changed the chassis power input to Furutech gold
and put some bitumen on the transformers for mechanical damping.
When I have finished the mods and upgrades I will post some picture.
I send a mail for Nicholas about 2 weeks ago hower I guess his SPAM filter eat it. I want his thoughts about if the following will improve the sound.
I was wonndering if someone had tried to use the DAC with putting
the PSU transfirmer and brigde outside the DAC cabinet or done some clock tweaking or change the regulation items with some super regulators.
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I received my dac and silver interconnects from Nick today. Fitted with the Burson discrete opamps, silver pulse transformer and an optical input.
It came very well packed and beautifully presented. The timber chassis is more a work of art than a commercial appliance.
I thought long and hard about what I wanted, and what I needed, but because of where I live, auditioning multiple dacs was never a possibility.
So any purchase was going to be something of a gamble. The benchmark for me was the Paradisea, which a friend owns. He plays around with tubes,
but otherwise it's standard, and it's a very impressive dac, which is about as expensive as I wanted to go. But Nick's ability to customize became a
telling blow. The Burson's over standard opamps, variable gain, which was huge for me, as the hard drive media center I'm using has very low output. Moving the jumpers to the 4v output fixed that.
Problems? My friends Paradisea was delivered in 4 days after paying on ebay. The Promi dac took over 17 weeks to get here. The incredibly long
wait combined with some complaints that surfaced after I had ordered, and the difficulties contacting Nick by email, made me very uncomfortable.
So there were definately plenty of times I wondered if I had made a mistake.
But all doubts were squashed the moment I turned it on. I'm not going to go on with a flowery disection of the sound quality. Quite simply, it is staggeringly
good. Brandi Carlile was performing in my loungeroom, and a steady stream of artists have followed her. If it continues to to improve as it burns in I'm
going to be extremely satisfied, for a long time. Compared to the Paradisea, without yet hearing them side by side, the Promi sounds in a different class,
it seems to do everything better. But a real comparison will have to wait.
The hum problem reported by some people, is completely absent in this unit. It is dead silent.
Many thanks to Nicholas. The long wait was well and truly worth it.
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Hi Copperhead,
Congratulations on your Promitheus DAC.
I had to sell my Altmann Attraction DAC and keep the Promitheus DAC for a long time comparison in my system. I also prefer the Promi DAC over Paradisea (old version).
Good choice indeed,
Tan
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I just been a lucky owner of this DAC. I am living Norway and is the 3th owner of it. I have been told by the seller that it is the last version and bought early this year. However I am not sure if the pulse
trafo is the silver one how can I check that? The one I got have the PCB and output trafo placed on wood.
At the moment I am looking forward to replace the output NE5234 with
the Burson modules.hey are will be fit in tomorrow and later on get their own dual PSU for the best working condition.
So fare I have just changed the chassis power input to Furutech gold
and put some bitumen on the transformers for mechanical damping.
When I have finished the mods and upgrades I will post some picture.
I send a mail for Nicholas about 2 weeks ago hower I guess his SPAM filter eat it. I want his thoughts about if the following will improve the sound.
I was wonndering if someone had tried to use the DAC with putting
the PSU transfirmer and brigde outside the DAC cabinet or done some clock tweaking or change the regulation items with some super regulators.
Can you resend the email again. COuld have miss it thanks
Your dac should have the silver pulse transformer as it has become a standard item for a while back already
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I will resend the mail again as I have been asked to do.
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Finally replaced the NE5534 by Sun discrete Opa - GD Audio. Much better than the 5534 in every aspect. Suggested Promitheus DAC user to replace the 5535 to either Sun discrete Opa or Burson Discrete opamp
Andis
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Finally replaced the NE5534 by Sun discrete Opa - GD Audio. Much better than the 5534 in every aspect. Suggested Promitheus DAC user to replace the 5535 to either Sun discrete Opa or Burson Discrete opamp
Andis
Hi Highfever,
Is this a drop in replacement and do you have to use the extension lead.?
Can you close the cover after installation and does it run very hot ?
You need to buy 2 pieces of the single opa ?
Thanks in advance
kp93300
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Yes, just a direct drop in, you can either use the extension cord (can cover the top plate if you put the Opamp aside), or put one more IC socket to make it higher so that there will be enough space to insert the opamp (but then you cannot cover the top plate).
I have ordered both the SUN and Moon discrete Opamp and SUN runs very hot with 2 very bright green LED/each opamp. You have to order 2 single opamp to replace the 2xNE5534. I found SUN is more dynamic and hi-fi sound while Moon is more natural.
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Hi Andis,
thanks for the reply.
will order the Moon to try .
Do you need to adjust the power supply of the DAC ?
kp93300
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I am not a technical guy, so dont know how to adjust the power supply and how/where to connect the ground wire. :duh:
Andis
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Hi, just ordered the Moon op-amps, anyone know where the ground wire should be soldered?
And everyone who has tweaked their unit....pictures please :D
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Hi, just ordered the Moon op-amps, anyone know where the ground wire should be soldered?
And everyone who has tweaked their unit....pictures please :D
Hi Milenko,
Closet ground point:
At the right side of Opamp where two transformers located, you will see four wires from PCB to transformer
inner group of color red and white come out from "G" on board, outer group of Red and White is signal.
So, you can solder to any color that come from "G".
Hope this help,
Mart
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That helps, thank you very much. That looks reasonably doable.
Just waiting for the opa-moons now, they are in shipment transit at the moment.
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Nick,
What's the price of your Dac with USB and Coax inputs and the Burson op-amp upgrade? And the lead time for shipment?
Thanks much,
Kevin
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Hi,
when grounding the opa-moon, what works best, ground on the input side of the output transformer or on the output of the output transformer? If that made any sense at all?
If i ground on the output side will it be better for the output transformer?
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Hi,
when grounding the opa-moon, what works best, ground on the input side of the output transformer or on the output of the output transformer? If that made any sense at all?
If i ground on the output side will it be better for the output transformer?
It does not matter since ground can be anywhere in the DAC. I soldered the ground of the Burson opamps to one of the closest screw of the PS transformer where the ground wire connected to the AC plug.
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Thank you, i soldered the ground to the output side of the transformer. Not the nicest lay out though, but that is easy to unsolder later on anyway. First impression, very satisfied, i feel the music flows more natural. It is almost as it breaths the music into the room.
This dac is an amazing buy and i guess a dream for every tweaker....
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Thank you, i soldered the ground to the output side of the transformer. Not the nicest lay out though, but that is easy to unsolder later on anyway. First impression, very satisfied, i feel the music flows more natural. It is almost as it breaths the music into the room.
This dac is an amazing buy and i guess a dream for every tweaker....
Yes, it is an absolute awesome dac after doing some tweaks (but no one would not believe this?!). That is the reason I sold my Altmann Attraction DAC. :thumb:
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I am inquiring to see if anyone on this forom who owns or has access to the manual for the Promitheus dac and would be willing to email me a copyof it.maybe i can reciprocate in some way.
Thanks in advance,
ronw
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Hey Tan (or anyone else with a manual handy),
I noticed that you reduced the output level of your DAC to 1 Volt. I just changed amps, and now one click up on my TVC and the volume is already pretty high. I'm too lazy to head to attic to try and find my owners manual for my DAC. Can you let me know how to set the jumpers so I am outputting 1 volt from my DAC?
Thanks,
Neil
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Hey Tan (or anyone else with a manual handy),
I noticed that you reduced the output level of your DAC to 1 Volt. I just changed amps, and now one click up on my TVC and the volume is already pretty high. I'm too lazy to head to attic to try and find my owners manual for my DAC. Can you let me know how to set the jumpers so I am outputting 1 volt from my DAC?
Thanks,
Neil
Neil,
The jumpers are located before the op amps if you look at the front DAC. Just use a small tip pliers to lift them up then you put the jumpers to the left side of the three.
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Thanks Tan! Will do.
Neil
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Thanks everyone for contributing to this thread. I have been looking for a DAC for the SqueezeBox Duet that I purchased recently. After extensive web research and reading all of the informative comments on this thread I just ordered the Promitheus DAC with the Burson op amp. I am really looking forward to receiving it.
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Thanks everyone for contributing to this thread. I have been looking for a DAC for the SqueezeBox Duet that I purchased recently. After extensive web research and reading all of the informative comments on this thread I just ordered the Promitheus DAC with the Burson op amp. I am really looking forward to receiving it.
Flathead,
You will not regret after the DAC is breaking in. But if you have a chance to modify the Duet to a truly 75 Ohm SPDIF (RCA) output you will be more happy to listen to your music.
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Thanks Tan!
I have been considering digital modifications for the Duet based on related comments. The Bolder Cable Company states the following for their 'Standard' digital modification for the Duet.
"We have come up with some changes to the internal parts that we feel improve the sound. We change the internal power supply reservoir capacitor to a higher quality item. We also remove everything in the digital signal path and run a 75 ohm coax direct to a WBT NextGen RCA. We have come up with some improvements based on our work on the RE-BOX project. We now including upgrades to the internal clock power supply."
I just e-mailed them to see if the mods to the internal clock power supply are included in this as they also have an 'Enthusiast' digital mod and it is difficult to tell what the difference is from the Standard mod.
The Standard mod is $200 USD and this seems reasonable given what appears to be included in the mod. Nonetheless I would like to keep the costs down if I can make some or most of these mods myself, particularly the changes required for the 75 Ohm SPDIF. I am a novice modifier and have only made one modification, a capacitor change in the Tice Power Block power conditioner. I am dangerous with a soldering iron, but I have the 'bug.'!
Can the modifications to the digital section of the Duet be done by a novice?
Thanks.
PS Tan - I really like the slide you have of the baby. What an expression! I have shown it to a hundred people.
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Thanks Tan!
I have been considering digital modifications for the Duet based on related comments. The Bolder Cable Company states the following for their 'Standard' digital modification for the Duet.
"We have come up with some changes to the internal parts that we feel improve the sound. We change the internal power supply reservoir capacitor to a higher quality item. We also remove everything in the digital signal path and run a 75 ohm coax direct to a WBT NextGen RCA. We have come up with some improvements based on our work on the RE-BOX project. We now including upgrades to the internal clock power supply."
I just e-mailed them to see if the mods to the internal clock power supply are included in this as they also have an 'Enthusiast' digital mod and it is difficult to tell what the difference is from the Standard mod.
The Standard mod is $200 USD and this seems reasonable given what appears to be included in the mod. Nonetheless I would like to keep the costs down if I can make some or most of these mods myself, particularly the changes required for the 75 Ohm SPDIF. I am a novice modifier and have only made one modification, a capacitor change in the Tice Power Block power conditioner. I am dangerous with a soldering iron, but I have the 'bug.'!
Can the modifications to the digital section of the Duet be done by a novice?
Thanks.
PS Tan - I really like the slide you have of the baby. What an expression! I have shown it to a hundred people.
Flathead,
I am not much different than a "novice modifier" and did all the mods by myself to the SB3 but not the Duet I used to own. I almost modified the Duet but finally did not and sold it ( I like a cool remote!). That is my starting point. As you know the most critical part is the output part at the chip but not the power supply since Pat (Art) had mentioned in other thread. If you want to do by yourself you should consult with him because I modified my SB3 based on his model. And the modification is actually an excellent idea to improve the digital output of the SB3 to any DAC with truly 75 Ohm IMO. You need to use an excellent 75 Ohm connectors and digital cable too.
Good luck,
Tan
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Thanks Tan, I will follow up on this thread. Started to do so just now.
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Nicolas,
the Dac is alway on. If I`m not using it, how many watts does it draw?
thanks
-
Shogun
The dac draws 10watts when its on.
hope this helps
Thanks
Nicholas
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Has anyone tried the GD Audio Discrete opamps? I just order two of their "Moon" model to substitute, and when I install them according to the instructions (minding the notch) I either get no sound (when I ground their ground leads to the chassis) or just clicking/ticking sounds if I leave them ungrounded (just plugged in). I contacted the manufacturer, and he confirmed that I had them installed correctly but had no idea why they didn't work. They are supposed to be fine with voltages ranging from 9V to 23V. Any suggestions would be much appreciated... and if anyone has tried any other op amp substitutions (besided the Bursons) that they love (just in case I can't get these to work) I'd love to hear about your experiences.
Neil
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My DAC
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1723
don't know how to add photo? anyone can help?
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(http://www.audiocircle.com/image.php?id=17945) :thumb:
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Satfrat,
thanks.
(http://www.audiocircle.com/gallery/displayimage.php?pos=-24482)
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Satfrat,
thanks.
(http://www.audiocircle.com/gallery/displayimage.php?pos=-24482)
Not a problem.
(http://www.audiocircle.com/image.php?id=17944)
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Hi walkern,
Actually, you can not put GD Audio Discrete opamps directly on PCB because its big base.
A small capacitor beside opamp connector will block your opamps, so it cannot firmly lock together.
You need extension cord (Audio GD has it) to solve this , or extend capacitor leg instead.
BTW, makes sure that you order "Single discrete opamp" not "Dual"
Mart,
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Neil,
You also need to adjust the output dc voltages of the gd opamps to match with the opt i guess unless the gd opamps can automatically adjust themself?!
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My DAC
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1723
don't know how to add photo? anyone can help?
How does your dac sound with those big O caps? Did you replace them in place of the two golden Phillip output caps? Looks interesting!
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i receive the DAC already with the caps installed. i am the 2nd owner. can't compare with the original spec. i enjoy the DAC very much.
compare to TDA 1541, it has more speed and dynamic. i guess Nich is quite familiar with the modification. may be he can add.
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Hey Mart and Tan,
Thanks for the advice regarding the GD discrete modules. I'd gotten the correct units (singles) and the extensions so I could hook them up without having to mess with anything on the main board, but I was assuming the chassis was an ideal place to attach the white "ground" wires. Oops! Those need to be attached to the signal grounds coming off the board to (and then from) the transformers on the right side of the DAC. Once I got the grounds connected correctly the units work like a champ... and I agree with the others who have tried them... they are a very worthwhile upgrade. And they work wonderfully at the +12 and - 12 volts the DACs are preset to, so I didn't have to adjust the voltage to them (whew!).
Neil
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Hi, first post here.
I’ve been following this thread for a while and received a Promitheus DAC earlier this week (used from original owner).
As several others have reported, mine also has a significant amount of hum/noise.
Has anyone with the hum/noise heard back from Promitheus on this, or resolved the issue in some other way?
Given that several folks are experiencing this, does this appear to be a design/quality issue with some units, or perhaps a part that gets easily damaged in shipping (mine was double-boxed and packed very well by the original owner, and I do not see any obvious internal damage)?
Here are my specific observations and things I tested:
The noise/hum is audible from my seat (3 meters from the speakers) when I pause my transport and when no track is playing, with the preamp’s volume at a moderate setting of around 9 o’clock. The noise/hum tracks with my preamp’s volume level.
The noise/hum is present when no digital cables are connected, as well as when a coax digital cable is connected. Interestingly, when no digital cables are connected there is a low hum and high whine from both the coax and BNC inputs. However, when a digital cable is connected to the coax input, the coax produces only the hum (no whine), but the BNC still produces the hum and whine.
In troubleshooting this, I tried all of the usual suspects – tried 2 different power cords, 2 different analog cables, 2 different AC circuits, moved the DAC to different locations, tried a cheater plug to lift the ground. Nothing had an impact on the noise/hum.
I also tried the various output voltage jumper positions. The noise/hum is present in all positions, but varies in relation to where the noise/hum becomes audible vs. preamp volume setting. The other thing I noticed is that the output voltage from my jumper settings does not appear to match what is in the manual. For example, the middle jumpers are the loudest on my unit, but according to the manual, the middle jumpers should be the middle (2v) output. Does this mean there is something wrong with my unit?
The one last thing I can think of to try is to get a RCA-BNC adapter and connect digital cables/sources to both digital inputs simultaneously. The thought here is to see if perhaps noise is entering the unused BNC input. I know this is a long shot.
I know that Nicholas from Promitheus posts on this thread, so I hope he (and others) will comment on this issue and how to resolve it.
I will also send Nicholas an email on this.
Thanks,
Adam
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Hi, first post here.
I’ve been following this thread for a while and received a Promitheus DAC earlier this week (used from original owner).
As several others have reported, mine also has a significant amount of hum/noise.
Has anyone with the hum/noise heard back from Promitheus on this, or resolved the issue in some other way?
Given that several folks are experiencing this, does this appear to be a design/quality issue with some units, or perhaps a part that gets easily damaged in shipping (mine was double-boxed and packed very well by the original owner, and I do not see any obvious internal damage)?
Here are my specific observations and things I tested:
The noise/hum is audible from my seat (3 meters from the speakers) when I pause my transport and when no track is playing, with the preamp’s volume at a moderate setting of around 9 o’clock. The noise/hum tracks with my preamp’s volume level.
The noise/hum is present when no digital cables are connected, as well as when a coax digital cable is connected. Interestingly, when no digital cables are connected there is a low hum and high whine from both the coax and BNC inputs. However, when a digital cable is connected to the coax input, the coax produces only the hum (no whine), but the BNC still produces the hum and whine.
In troubleshooting this, I tried all of the usual suspects – tried 2 different power cords, 2 different analog cables, 2 different AC circuits, moved the DAC to different locations, tried a cheater plug to lift the ground. Nothing had an impact on the noise/hum.
I also tried the various output voltage jumper positions. The noise/hum is present in all positions, but varies in relation to where the noise/hum becomes audible vs. preamp volume setting. The other thing I noticed is that the output voltage from my jumper settings does not appear to match what is in the manual. For example, the middle jumpers are the loudest on my unit, but according to the manual, the middle jumpers should be the middle (2v) output. Does this mean there is something wrong with my unit?
The one last thing I can think of to try is to get a RCA-BNC adapter and connect digital cables/sources to both digital inputs simultaneously. The thought here is to see if perhaps noise is entering the unused BNC input. I know this is a long shot.
I know that Nicholas from Promitheus posts on this thread, so I hope he (and others) will comment on this issue and how to resolve it.
I will also send Nicholas an email on this.
Thanks,
Adam
Adam,
I do not have problems of hum/noise in my DAC. The only one problem is I can use (have signal) this DAC in my system but it does not have signal in other system (like I stated before in this thread).
You might use a truly 75 Ohm digital cable to avoid those problems IMO. I got the Silver digital cable (well grounded hand made).
Good luck,
Tan
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Adam
Drop me an email with pics of the board. Then from there i can advise you better
thanks
Nicholas
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Tan, thanks for the reply.
I have the noise even when no digital cables are connected.
I did get a RCA-BNC adapter today, so I'm going to connect transports to both digital inputs to see if that has any effect.
Nicholas, I emailed you a link with pictures from the original owner. Let me know if they are adequate.
Thanks,
Adam
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Well, I ran the experiment with both digital inputs connected to transports. This did not eliminate the hum/noise. I figured this was low probability.
I also connected the DAC's analog outputs to my home theater receiver for an experiment, and the hum/noise was present there also.
I hope there is a solution, because I really think I would enjoy the sound of this DAC if the hum/noise were not present. The hum/noise is distracting during track changes and simply should not be present.
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I also have a hum in my dac, i dont notice it when i am playing music but it is a bit annoying when changin cds skipping tracks......
The hum has always been there, i recently changed the op-amps to the opa-moons, got a bit sweeter sound.
When that is said, i must say that i really love the sound of this dac, it is stunningly good, a bit annoyed by the hum issue though, but in every other instances it is perfect and a great product....
Any one know how to solve the hum issue?
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Adam
If you can send me the board back, i can get it fix and send it back to you
i just need the board only to fix it
thanks
Nicholas
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Adam
If you can send me the board back, i can get it fix and send it back to you
i just need the board only to fix it
thanks
Nicholas
Nicholas,
Could you see something “wrong” with the board from the pics in the link I emailed you last week?
Thanks for the offer to look at the board. However, desoldering, shipping, and resoldering the board are not an option for me, as I do not have soldering experience/tools.
The original owner has agreed to provide a refund, so I will be shipping it back to him.
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Adam
If you can send me the board back, i can get it fix and send it back to you
i just need the board only to fix it
thanks
Nicholas
Nicholas,
Could you see something “wrong” with the board from the pics in the link I emailed you last week?
Thanks for the offer to look at the board. However, desoldering, shipping, and resoldering the board are not an option for me, as I do not have soldering experience/tools.
The original owner has agreed to provide a refund, so I will be shipping it back to him.
Adam,
My opinion is you just save some more cash to get a brand new DAC from Nick. It is worth the money and is a fraction of the price compared to >1K DAC sonically. I used to buy so many kind of DACs but end up to keep this one. :thumb:
I got a problem with the previous board of my DAC too and Nick sent me a brand new one to replace it. At that time I was wobbling to desolder and solder the boards but I got a good result. :rotflmao:
Good luck,
Tan
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Hey Mart and Tan,
Thanks for the advice regarding the GD discrete modules. I'd gotten the correct units (singles) and the extensions so I could hook them up without having to mess with anything on the main board, but I was assuming the chassis was an ideal place to attach the white "ground" wires. Oops! Those need to be attached to the signal grounds coming off the board to (and then from) the transformers on the right side of the DAC. Once I got the grounds connected correctly the units work like a champ... and I agree with the others who have tried them... they are a very worthwhile upgrade. And they work wonderfully at the +12 and - 12 volts the DACs are preset to, so I didn't have to adjust the voltage to them (whew!).
Neil
Walkern,
Glad to hear the upgrade was worthwhile. Would you mind sharing with us how the GD discrete modules improved on the already great sounding DAC?
Thanks,
Craig
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Hi Craig,
I e-mailed the folks at GD Audio and basically said my DAC now sounds more like good vinyl. Marginal discs are less offensive sounding and well recorded discs sound spectacular. Instruments seem to have more body and more accurate tonal characteristics, and in some cases more weight (double bass for example). Singers seem more present (3D) or in the room with me (or me with them), and female vocals that previously could sound a bit shrill are more relaxed and smoother sounding. The extreme top end seems to have a bit more clarity and shimmer (can hear more of the harmonics of instruments like cymbals or triangles or bells), and seems a bit more extended as well. The DAC seems to be capturing and revealing more information (lyrics seem more intelligible), yet simultaneously it sounds more organic or musically natural. I was at a local symphony concert last weekend and came home and fired up recordings of what had been played and was pleasantly surprised with how close my system matched the general character of the orchestra. Previous trips to the symphony have lead me down the upgrade path more often than not. The dynamics seem a smidge more ... uh... dynamic, both micro and macro. The bottom line is, I find myself listening to more music, and re-discovering all sorts of discs, and I am watching TV and reading less. Always a good sign.
Neil
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Hi Craig,
I e-mailed the folks at GD Audio and basically said my DAC now sounds more like good vinyl. Marginal discs are less offensive sounding and well recorded discs sound spectacular. Instruments seem to have more body and more accurate tonal characteristics, and in some cases more weight (double bass for example). Singers seem more present (3D) or in the room with me (or me with them), and female vocals that previously could sound a bit shrill are more relaxed and smoother sounding. The extreme top end seems to have a bit more clarity and shimmer (can hear more of the harmonics of instruments like cymbals or triangles or bells), and seems a bit more extended as well. The DAC seems to be capturing and revealing more information (lyrics seem more intelligible), yet simultaneously it sounds more organic or musically natural. I was at a local symphony concert last weekend and came home and fired up recordings of what had been played and was pleasantly surprised with how close my system matched the general character of the orchestra. Previous trips to the symphony have lead me down the upgrade path more often than not. The dynamics seem a smidge more ... uh... dynamic, both micro and macro. The bottom line is, I find myself listening to more music, and re-discovering all sorts of discs, and I am watching TV and reading less. Always a good sign.
Neil
Neil,
If I could acheive the types of improvements you describe, the DAC may be just about perfect in my system. It already sounds great, but there's always room for improvement, if you know what I mean. Thanks so much for the detailed description.
Craig
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Good to hear you like the GD audio stuff.
We are now focusing more with the Burson audio. Now i am keeping them in stock for use with our DAC.
I prefered the Burson over the GD audio when i compared them
Will do a special "burson edition" dac shortly
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Good to hear you like the GD audio stuff.
We are now focusing more with the Burson audio. Now i am keeping them in stock for use with our DAC.
I prefered the Burson over the GD audio when i compared them
Will do a special "burson edition" dac shortly
I agree with Nick. I have had the DAC with Burson opamps installed and never look back to all DACs (same league with NOS DAC) I own before included Altmann Attraction DAC. At least you need to have a reference DAC to compare with.
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Can someone please post a picture of the Moon OPA's installed in the DAC, I want to see where the ground wires are soldered exactly. :scratch:
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I soldered mine to the ground out on the output transformers
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Can someone please post a picture of the Moon OPA's installed in the DAC, I want to see where the ground wires are soldered exactly. :scratch:
You can solder to the ground found at the power supply tranny which is closer to the pcb dac. I am sure they have same grounds like Burson.
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Hi,
Any review of the C-cored DAC? Very interested in this one. Also, with the hum problem, do you think the separate power supply will improve if not totally eliminate it?
thanks
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I hope that Nicholas will not mind me butting in on his circle, especially with all that is going on today, but I have a question for the person who made the following post.
It is generally accepted that clock jitter below 200ps rms is inaudible; although there are some who claim to hear as little as 2ps. Most S/PDIF receivers have <200ps jitter. So, the question is: Why would a DAC designer deliberately increase clock jitter by orders of magnitude, as is the case with asynchronous reclocking, and why doesn’t anybody hear it?
Why do people such as yourself throw around buzz words like this, without even specifying what the hell they are talking about?
Are you talking about word clock jitter? Bit clock jitter? The same amount of phase noise gives much different jitter numbers. On top of that, whether or not the jitter is data-correlated is also important. But you make no mention of that, just regurgitate the same ol' "jitter below a certain level is inaudible" assertion.
I agree with JohnR and Chair Guy that this sort of discussion belongs in the Lab section. Where people who know what they are talking about can 'splain it to you without making a muck of someone's Circle.
For the record, I do not know who Nicholas is, what his company is, what they make and whether or not it is any good. BS is just BS, and needs to be confronted wherever it pops up.
Please forgive my butting in, and let's hope this place is still here on Monday morning.
Pat
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Hi,
Someone have any updates about the promitheus dac ?