[PromitheusAudio]

Was curious about the dimensions of this DAC and if there would be some tube(s) in the design?

    - jaspal.
[/quote]

THat's the 2nd model. First model is based on solidstate. Even for me, a predominant tube fan i find the DAC very tube like with solidstate  benefits.

Actually when we compared back to back with a AN DAC2 (tube) there was not much difference in the tonal balance even though mine was solidstate

However just to feel macho, i am starting to make the DAC too, with tube output. I believe the tube with output transformers would be far better than the solidstate version but then again its a matter of cost.  

[PromitheusAudio]

It appears that the DAC is SS...what I can't tell are the types of connection...USB, Toslink, what?

And because it's SS I'll need to buy the active tube from Nicholas too. JEEZ!

ITs not about the gain for the tvc with the active stage its a completion of picture when used. Even if i used high gain on the DAc set to 4 volts. I could not get the same completion of picture when I used the TVC alone. Its like if you thought the TVC was good, having it with the active stage is a hold different story REGARDless of what you put before

[PromitheusAudio]

Hey Nick .Nice DAC! How about a USB port for the PC audio guys like myself?

Thanks

Because we are selling it at low price range we were put all efforts in to the transformers, the USB port option is available but as an extra option. ALso why its an extra not everyone needs them. SO if you need them with the DAC just get the USB option as an extra

[anubisgrau]

i am wondering if there is any sonic reason why nuts on volume switch (more) and input selector (less) are not fully tighten? i remember someone mentioned this earlier on the forum too.

i tighten it now very strongly because i hate if this is loose, but could it be that i killed some sonics with it? i have no enough time to screw and unscrew the knobs in order to hear it myself so if anyone went that far in tweaking the TVC, i would appreciate if he could share the thoughts.

[GHM]

Hey Nick .Nice DAC! How about a USB port for the PC audio guys like myself?

Thanks

Because we are selling it at low price range we were put all efforts in to the transformers, the USB port option is available but as an extra option. ALso why its an extra not everyone needs them. SO if you need them with the DAC just get the USB option as an extra

Hey Nick .Nice DAC! How about a USB port for the PC audio guys like myself?

Thanks

Because we are selling it at low price range we were put all efforts in to the transformers, the USB port option is available but as an extra option. ALso why its an extra not everyone needs them. SO if you need them with the DAC just get the USB option as an extra

Thanks Nick..I'll be ordering one with the USB port..I can't live or listen without it now.
I think once people realize how good going USB direct sounds. You'll be making them all with this installed.

[gooberdude]

Hey Gordon,

I don't think tightening the allen screws that hold the volume & Selector knobs should do any harm.
i replaced the metal dowel rod on the Selector swtich with a ten cent wood dowel, then tightened the heck out of the allen screws.

the allen screwes are really small on the ebony knobs, you have to keep them tight or some play will develop on the knob.

To me, the heft or damping properties of the ebony knobs are beneficial to the sound...don't Isolate them by leaving screws loose.  Couple them to the dowel...


Hey Guys,

the experience with the tiny Trenda TA-10.1 still has me boggled.   I think what I stumbled across is that our TVC can sound wicked (more than usual!) if we can listen with the volume open 100%.  This requires an integrated amp, or essentially a 2nd volume control.     Has anyone tried using the TVC this way???

Last night I unwrapped a pair of Hawthorne Audio Silver Iris OB drivers which are a holographic audio tool of the highest order.  i'm going to get a low powered amp & i might go with a tube integrated just to operate the TVC in the way described above...    More tinkering is in order for sure, but using the TVC as a buffer of sorts netted amazing sonic improvements.

[NewBuyer]

Because we are selling it at low price range we were put all efforts in to the transformers, the USB port option is available but as an extra option. ALso why its an extra not everyone needs them. SO if you need them with the DAC just get the USB option as an extra

This is a very nice optional feature. Will the USB port be transformer isolated?

[anubisgrau]

mine TVC is now in the 3rd day ( ) of run-in and i've had to plug it back into the main system just to see where it goes. i use balanced (XLR) outs to my active boxes. so first i plugged the CDP via balanced inputs of promitheus and was rather shocked to hear a very very different sound to what it had 2 days ago when i just briefly tested in and was very pleased with the first impressions.
to my shock now the bass was completely gone - non existent, zero, nada - and the rest of the spectrum is just flat - it almost sounds like mono! 
than i remembered that i didn't use balanced inputs when i tested it so i plug the player again via RCA inputs and the sound was fully back to normal, actually i could even now hear the mids are relaxing, while the bass is nice and deep, rolling fat
also during the run-in process i use the same RCA inputs (although not the XLR outs but RCAs).
i am a bit confused with what i heard via balanced input. could it be there is some problem with the way XLR is wired, or with an input switch (grayhill, btw it seems to be very good and very solid - a good ceramic stuff, i really didn't like a plastic switch you find on a normal version).
has anyone experience anything even remotely strange like this - that the same source sounds completely different through different inputs!?
just don't tell me i have to run-in every input and output on the TVC separately

[anubisgrau]

i am really very pleasantly surprised with the sound of the 3rd generation trannies. i think that nick is really extracting a real maximum from the EI core, even regardless the price. considering that i can see at least 2 important tweaks to be done with the stock unit, i am sure it will be possible to tune it to kill any S&B based unit. there are a couple of things nick as a constructor did fundamentally right - against what is usually found in commercial units.

for example what i like is that he left trannies unshielded. whatever measurements will tell you, to get the best sound out of a good ole trannie, you are not allowed to interfere with its own magnetic field! i am talking about the sound and not the measurements!

this is where S&B got it wrong but i anyway think they shielded their trannies to hide what they actually charge a shitload of money, not for other (sonic) reasons.

once mine is fully run it, the first tweak i'm going to do is to remove both the cover (OK this is already done) and the bottom steel plate. for the bottom i am going to use 2" wood support i bought from nick that is apparently made from the same wood as the promitheus case. what i wanna do is to actually screw the trannies directly into the thick wood plate. i still have to find out how to make one case out of the TVCs case and the support but hopefully i'll make it right - i am sure i can make less damage to the sound than steel close to the trannies.

also, can anyone tell me if the 3rd generation of trannies is one size bigger than the previous one or i am tripping?

[rollo]

annubisgru,
                    If I may offer a suggestion to your screwing trannies to wood plinth. If you would like to take to another level, purchase ebony pen blanks[3/4"x 3/4"] and mount trannies on them and then to wood plinth. To compensate for the added height you could also glue pencil blanks to perimeter of wood plinth and then secure to enclosure.
                 As effective as the wood plinth is ebony IMO is the ticket. By the way the pencil blanks are approx $2 each.
                With reference to the sound through the balanced outputs, they require break in as well. The only problem I could imagine is that the pins are wired differently for the connecting component. Nicholas should be able to answer that question.

  happy listening

  rollo 

P.S. The steel plates are stainless steel which are non magnetic. IMO the wood just dissapates the vibration of the trannies better.

[stereohifi]

annubisgru,
                    If I may offer a suggestion to your screwing trannies to wood plinth. If you would like to take to another level, purchase ebony pen blanks[3/4"x 3/4"] and mount trannies on them and then to wood plinth. To compensate for the added height you could also glue pencil blanks to perimeter of wood plinth and then secure to enclosure.
                 As effective as the wood plinth is ebony IMO is the ticket. By the way the pencil blanks are approx $2 each.
                With reference to the sound through the balanced outputs, they require break in as well. The only problem I could imagine is that the pins are wired differently for the connecting component. Nicholas should be able to answer that question.

  happy listening

  rollo 

P.S. The steel plates are stainless steel which are non magnetic. IMO the wood just dissapates the vibration of the trannies better.

The same idea for my upcomming ref. TVC will be to use a wood plint. As i have done a special order for sitka spruce, the wood used for piano soundboard, i will experiment that.
Wood shafts will be used also for the control and volumes i already have maple sticks for that.
i hope to get my TVC soon after easter as Nicolas promised......
I will keep you posted.
regards...

[daz_bike]

Stereohifi,

I hope the wait is worth it.  When did you order by the way.  I'm thinking the current wait is around 2months?

Interesting idea regarding the sitka wood and I hope it works for you.  Please let us know.  I think the wooden shafts for the control knobs will be a given over metal.

Stainless steel will be very good at picking up vibrations in the unit and I plan to deal with the vibrations using Tungsten Carbide ball bearings sitting on carbon graphite blocks ala Tuneblocks.  I will see how that goes and report once I get my TVC.

There seems to be no end of tweaks on these units!

Regards

[Oscillate]

Nicholas, please check your PMs.

          ~~~~~~~~~

I bought a Reference Dual Box TVC a week ago. The next day I E-mailed to inquire about
price and avilability of a Hybrid Amplifier (...and now an Active Preamp also) Might as well
get an entire Promitheus system for the best sound quality and value It's been a week
and no response yet. Is nicholas@promitheusaudio.com the best way to contact Nicholas?

Newbie question follows... Is the Hybrid Amplifier considered a 'class A' design?

[PromitheusAudio]

Stereohifi

Could you let me know your email address or name you order that way i can track and update you on the process

oscillate

Did not get your email from you but i reply the audiocircle mail and resend it to you.


Guys if you don;t hear from me just send me a PM via audiocircle and i will respond. So far i know i did not recieve 2 emails, one from oscillate and another from another gentleman.

On tweaking, like rollo's statement it ain't high end unless it can be tweaked. 

[robert1325]

Does anyone know how this DAC would compare with the MHDT labs paradisea?  Using USB input...

They seem very similar to each other... Maybe not actually , the promitheus one with it's seperate PS seems much more sophisticated ....  My dad is looking for a good USB DAC,  or Modded squeezebox
( USB DAC is  a lot cheaper)    And is currently considering a Paradisea 

[studley]

Nic
Re the DAC:

1. How much $extra is the USB input?
2. When will the valve version be available?
3. Will the valve version have a USB option?

Thanks
Ian

[anubisgrau]

P.S. The steel plates are stainless steel which are non magnetic. IMO the wood just dissapates the vibration of the trannies better.

Ja! Natürlich, but now Rollo we are talking about engineer vs listener approach. My buddies who built the best TVC I've ever heard, did extensive listening tests with transformers and stainless steel around them and they are clear: it should be avoid for the best results: it soaks energy and dynamics from the sound. It loses the final natural, organic element of it.

I can trust them because this is where both Promitheus and S&B sourced TVCs are clearly inferior to their TVC. Btw the testing of the DIY TVC (I wrote about earlier) was repeated against a state of the art S&B sourced TVC in much higher rez system than mine (including speakers of Proac D80 class) and our initial findings were confirmed: no S&B TVC can hold its own against it.

Re TVC sounding broken via XLRs, this can't be an issue of running them in. Absolute lack of bass might lead me to think of some kind of polarity issue, like when you mess + and - and speakers - the only difference here is that I don't have a fake almost like a surround ambience but a completely flat, mono mids. Nick?

[rollo]

P.S. The steel plates are stainless steel which are non magnetic. IMO the wood just dis sapates the vibration of the trannies better.

Ja! Natürlich, but now Rollo we are talking about engineer vs listener approach. My buddies who built the best TVC I've ever heard, did extensive listening tests with transformers and stainless steel around them and they are clear: it should be avoid for the best results: it soaks energy and dynamics from the sound. It loses the final natural, organic element of it.

I can trust them because this is where both Promitheus and S&B sourced TVCs are clearly inferior to their TVC. Btw the testing of the DIY TVC (I wrote about earlier) was repeated against a state of the art S&B sourced TVC in much higher rez system than mine (including speakers of Proac D80 class) and our initial findings were confirmed: no S&B TVC can hold its own against it.

Re TVC sounding broken via XLRs, this can't be an issue of running them in. Absolute lack of bass might lead me to think of some kind of polarity issue, like when you mess + and - and speakers - the only difference here is that I don't have a fake almost like a surround ambiance but a completely flat, mono mids. Nick?

 

 anubisgru,

                     I am agreeing with you that wood or ebony is the way to go. Just letting you know plates are Stainlees Steel and non magnetic. We all have discovered that with top cover off sonics are improved. When you attach trannies to wood I am with you that it is an improvement. In the future maybe an all wood enclosure may appear again with a thicker wood base and top plate. Maybe Nicholas can offer a wood plinth direct replacement of S/S plates for existing units as an option.  Say a thick wood base 2" or so and a wood top.
      rollo

   P.S. Are you or your friends trying to market this device or is it for personal use only?

[anubisgrau]

   P.S. Are you or your friends trying to market this device or is it for personal use only?

unfortunately not - or at least not yet. as nick can probably testimony better than me, there are so many restricitions in pushing a concept of the perfect TVC to the limit that it makes a commercial exploitation almost impossible.

our findings are very simple: the cores has to be double-C, they should be big (even bigger than the current, Rev 3 trannies from promithes) and if anyhow possible the cores should be old. this is the most difficult to find, the double-C cores produces god knows when, whose molecular structure has "relaxed" over time. and - we believe that the best material is nothing really high tech (as S&B - permalloy plus kobalt) - on opposite we think that the best sounding combination according to our findings are iron with some % of silicium. nothing more exotic than this, but if possible, they should be as old as possible.

given this input for a sound perfection, you will see that this is not going to be commercialized - or at least i can't see how this can be done.

i will be happy to secure only a piece for me, but it seems a long way until than.

but if i travel to NYC soon, i'll take care to bring it with me. you will be shocked.

[tanchiro58]

   P.S. Are you or your friends trying to market this device or is it for personal use only?

unfortunately not - or at least not yet. as nick can probably testimony better than me, there are so many restricitions in pushing a concept of the perfect TVC to the limit that it makes a commercial exploitation almost impossible.

our findings are very simple: the cores has to be double-C, they should be big (even bigger than the current, Rev 3 trannies from promithes) and if anyhow possible the cores should be old. this is the most difficult to find, the double-C cores produces god knows when, whose molecular structure has "relaxed" over time. and - we believe that the best material is nothing really high tech (as S&B - permalloy plus kobalt) - on opposite we think that the best sounding combination according to our findings are iron with some % of silicium. nothing more exotic than this, but if possible, they should be as old as possible.

given this input for a sound perfection, you will see that this is not going to be commercialized - or at least i can't see how this can be done.

i will be happy to secure only a piece for me, but it seems a long way until than.

but if i travel to NYC soon, i'll take care to bring it with me. you will be shocked.

Just want to let you know that Double-C core trannies are not the best nowadays. As I know only the R cores can be the best trannies outhere. Therefore, Kondo Shan of Audio Note has succeed with his push pull tube amplifiers.

I do have my 2A3 parallel SET amp which has double C-core output transformers. It sounds a lot better than other brand name amplifiers like Cary, CJ, Audio Research, etc... But once I have listened to the 300B push pull with R-core output transformers then I know I have not reached to the extreme yet.