Promitheus DAC anyone?

tanchiro58 · « **Reply #260 on:** 2 Mar 2008, 07:15 am »

Quote from: highdfever on 2 Mar 2008, 05:19 am

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

PromitheusAudio · « **Reply #261 on:** 2 Mar 2008, 01:11 pm »

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

GHM · « **Reply #262 on:** 2 Mar 2008, 01:26 pm »

Quote from: highdfever on 2 Mar 2008, 05:19 am

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.

PromitheusAudio · « **Reply #263 on:** 3 Mar 2008, 04:29 am »

Just to inform every one that Affordable Audio has come up with their March Issue
And our DAC is reviewed in this March Issue

highdfever · « **Reply #264 on:** 3 Mar 2008, 12:33 pm »

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

tanchiro58 · « **Reply #265 on:** 3 Mar 2008, 07:05 pm »

Quote from: highdfever on 3 Mar 2008, 12:33 pm

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

PromitheusAudio · « **Reply #266 on:** 6 Mar 2008, 01:47 pm »

tan

i posted before on how to tune the voltage

Quote

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.

tanchiro58 · « **Reply #267 on:** 7 Mar 2008, 07:22 am »

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

katza · « **Reply #268 on:** 24 Mar 2008, 05:15 am »

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.

vkaiwar · « **Reply #269 on:** 31 Mar 2008, 03:51 pm »

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.

jalpendre · « **Reply #270 on:** 10 Apr 2008, 09:33 am »

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.

kp93300 · « **Reply #271 on:** 12 Apr 2008, 05:22 pm »

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

elb · « **Reply #272 on:** 18 Apr 2008, 07:23 am »

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.

NewBuyer · « **Reply #273 on:** 21 Apr 2008, 02:16 am »

Quote from: elb on 18 Apr 2008, 07:23 am

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...

supergroverd · « **Reply #274 on:** 21 Apr 2008, 11:48 am »

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........

kbuzz3 · « **Reply #275 on:** 21 Apr 2008, 06:33 pm »

i guess now is not the time to ask what the average lead time is for a dac..

elb · « **Reply #276 on:** 22 Apr 2008, 01:20 am »

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.

NewBuyer · « **Reply #277 on:** 3 May 2008, 06:25 am »

Quote from: tanchiro58 on 7 Mar 2008, 07:22 am

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)...

Dexsam · « **Reply #278 on:** 22 May 2008, 02:25 am »

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

tanchiro58 · « **Reply #279 on:** 22 May 2008, 03:19 am »

Quote from: Dexsam on 22 May 2008, 02:25 am

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.