Tube DACs

iFi Pro iDSD able to turn on tube mode or off tube mode. 

@hickamore

There are a number of dacs with tubes. Some have volume (Lampizator, Totaldac D1-Tube) some don’t (Aqua La Scala). Some skeptics may opine that they color the sound….but what doesn’t? VERY few dac, be they solid state or tube output stage, do a great job driving an amp directly. I’ve tried it for years with varying degrees of success.

I think of the volume control on a dac as a way to “match” the dac output to the optimal input level of the preamp/integrated. MSB, Lampizator, DCS, Totaldac…all sound pretty good driving direct but not at their best. Think about it, few dac builders are going to take the time or go to the expense to implement an output stage that tops that of the better output stages found in better preamps. In addition, fitting it all optimally into a single chassis introduces a whole different set of issues. My 2 cents.

I run a Jadis tube dac through my Lamm LL2.1 deluxe all tube preamp and it sounds marvelous. Enjoy the music

I own both tubed DAC and preamp. Definitely a very synergistic combination. In my system especially since both are Audio Research. Absolutely nothing wrong combining different brands.

One thing I must comment on is the word “random”. I assume you did not really mean just combining two different brands randomly. But that research into the sound quality of each… and particularly when buying the second is a part of your process.

I definitely do recommend both. Quite honestly when I added my tube DAC… it was astonishing how much more musical and realistic my system got.

Thanks to all for the informative answers. Somehow I had forgotten those tube DACs having no volume control. So what about pairing tube DAC with SS preamp? (Not that I'm planning any experiments, and if I did, @ghdprentice is correct, they wouldn't really be "random"). 

If those dac manufacturers didn't expect it to be used directly to amps, they should just leave off the volume controls,  no sense having the signal go through two analog stages, one good and one crappy. 

The rule is that there is no rule.  

@allanblissett every dac has an analog output stage, volume or no volume.

Obviously if a DAC has a tube, the tube has nothing to do with digital. It is usually a cathode follower for impedance matching to the device the DAC is feeding and it's there to color the sound to be tube like(otherwise it's colored solid state like).

@allanblissett volume control inside a dac is often done digitally,  and if done right causes no loss of resolution. 

AFAIC tubes should be in every possible gain or buffer stage. 🙂

There are many great solid state preamps. Nothing wrong, at all, with using one. I still prefer high end tubed preamps. When I have compared similar prices ss and tubed preamps I have preferred the tubed… they have a more natural and musical presentation. There are probably exceptions.

Controlling amps directly from DACs is not a thing yet. Many people have tried it and most have abandoned it. You end up with great details and a sterile sound. I suspect over the next twenty years this will slowly change as digital dominates the market and analog becomes less main stream.

But for now, unless you want to put out a lot of money, a lot of research time and probably buy you DAC (non-tube) and amp from the same manufacturer, it is better to assume you need a high quality DAC and Preamp.

All components have a sound. Tube DACs were not designed to eliminate the preamp any more than a tube phono pre is. Yes tubes into tubes could get too tubey but if they are well designed they will probably work fine. No generalizations are possible.

I have a Black Ice tube DAC (new purchase, very happy) playing through a Raven integrated tube amp. Sounds really good, starting to rival my analogue front end.

It has a gain control, which doubles as a volume control for headphones. It is not designed to be connected directly to a power amp as far as I know.

I went with a Tube DAC with the intention of tube rolling, which I did immediately. Huge change after adding some NOS Mullard’s. Done for now.

No reason not to use a Tube DAC with a SS amp. Or the converse...my phono stage is SS. IMO the Cart/TT does the sound shaping and I wanted a clean, quiet transfer from the PS.

"Tube DACs were not designed to eliminate the preamp any more than a tube phono pre is."

The above succinctly states what all responses are telling me, and thanks for it. There are those who run streamer/dac/pre combo units straight to amp. But none of these products are tubed so far as I'm aware . . . ?

Why ? Tube dacs can sound very good but there are far more SS dacs that are better in several areas  for under$7 k World class T&A 200 dac 

that is next on my list it is exceptional and I have heard many dacs at 2x the cost 

not as good.

@audioman58 The T+A DAC 200 is actually top of my list. With a tube preamp always. Whether a tube DAC would better sit my ears is TBD.

Well I am waiting on my first Audio tube component ( I have 2 tube amps for bass guitar, and 2 hybrids), an Ayon Kronos Signature DAC. It will be XLR'd into my ML 523 pre, and taking signal from an AES connection from the HiFi Rose RS150B. Pretty excited.  Even though the tube bass amps have a special sound, I use my hybrid tube pre/mosfet power amp the most.  So I am hoping for the same excellence with the new DAC.

I have the Line Magnetic LM-32 DAC. It has a button to select either tube or SS. I also have a tube pre and a tube amp. Sounds fantastic. Closest I have gotten to sounding like my vinyl side. 

I recently upgraded to a Nagra Tube Dac and Power Supply and have that running into my ARC Ref6se and ARC Ref160S.  Spent about 1 year searching and demoing different both SS and tube and this is where I landed. Ironically, I switched from a Roon Nucleus + to a NUC and have am using a  Lumin as a stream in between my NUC and my Nagra.  The Lumin adds better sound quality , in my opinion, than streaming with the Nucleus +.

Let us know how you make out.

I have been using my Ayon Stealth Xs DAC for just over two years now. The sound still blows me away every time I listen to it. It uses 4 6N6P output tubes and 4 tubes in the voltage regulator section. I have their CD II Transport which is also fantastic but now I mostly stream. This DAC showed me redbook CD has a lot more to offer than I ever thought possible. I used to mostly play vinyl but now I mostly listen to digital. This DAC wrings detail and resolution out of CDs that I had no idea was even there- that this level of detail down in the lowest quietest passages just did not exist on CDs. I had a Ref CD player before and I thought it sounded natural but I still would only listen to one CD typically before switching to vinyl. Now I listen to digital for hours.

The Ayon DAC can be used direct to Amp. It has switches on the back that change the output gain hi/lo and a direct amp setting that insures the volume will be near minimum when the DAC is powered on. In non preamp mode the volume control is bypassed. I use bal connectors and I route the music through an ARC Ref 5SE to a pair of Pass Labs monos. I prefer using a preamp between the DAC and amps. I have tried the DAC connected directly to the amp. The sound is different. I found I preferred the sound better going through my preamp. It might be a coloration and most likely it’s just because that is the sound I am used to. It is also for convenience since I listen to vinyl too. The only downside to direct to amp is that the noise floor is slightly elevated. Through the preamp everything is dead quiet- even standing by the speakers. But when connected direct I could just hear a bit of tube noise from my listening chair. Not a big deal but it is there. The Ayon manual addresses it. The manual states that when using the DAC direct some tube noise is apparent because the DAC has no negative feedback and uses large, low resistance capacitors in the output stage. They added that the DAC can be modified to reduce the tube noise but at the cost of a slight performance reduction. The manual states that the tubes should last 8000 hours, as I recall.  I put about 1300 hours/year on it based on my preamp hour meter.

I have a picture of the DAC’s innards on my system page. It is beautifully made as can be seen in the picture. Their next DAC model up uses 6H30 output tubes. I have not heard that version. The 6N6P version however is definitely a winner.

As pointed out already, there’s not much random in your counselling others, and experimenting, to find a combination that allows you to hear deep into your music. I echo the finding of Ayon eqpt. noted in post above.

If you have a tube transport / DAC AND power amp capability / sound character that you value highly, you might try eliminating the relative complication and noise of a pre-amp in favour of a transformer volume control (TVC) or similar device: if you like your upstream components, your music could be revealed much more transparently and richly, depending, of course, upon a positive mating of your components. Enjoy your search.

I don’t think there’s anything wrong with running a tube dac through a tube pre, unless the point is there’s no need to do that, because you you already get tube sound through the pre.  I agree that there’s synergy in coupling tube components together. In my case, in my vintage system I run a jolida tube dac thru a McIntosh MX110z, mated with 2 McIntosh MC30s. 

@smoorenc - yeah, I have an older Line Magnetic, LM502ca - really a wonderful piece and once you get the Chinese tubes out of it and toss in some "better" 12au7 or 5814A (Telefunken, Amperex, RCA clear tops, etc.) it really becomes shockingly good. I run tubes in my Linestage & Power Amp and sometimes it's a bit less dynamic than I'd prefer but for 99% of my listening its a glorious DAC & setup. All modest components compared to many on this site but, synergy between the gear in my main rack is fabulous. 

"you might try eliminating the relative complication and noise of a pre-amp in favour of a transformer volume control (TVC) or similar device:"

In my case that's not an option because I use 3 analog inputs besides the 2 DACs. Well, maybe if I ran the main DAC via single end to amps. TVC is very much in the picture either way, however. Room correction needed whatever the electronics.

I had thought the same myself. Can tubes cancel each other out? Tubes are in the chain to achieve a particular sound signature you like. This is the whole idea behind tube rolling. There are tube dac tube phono pre amps and tube amps snd tube pre Amps that can all be in one chain. Every link in the chain will effect the output sound. This does not necessary make it bad but would need slot of adjustments. My biggest concern is that most tube stages add gain into the signal path and if you are adding gain of 12 + 14 how much distortion can be you end signal or output. I like the flexibility of my Freya pre if I had a tube dac I could take the tube stage out of the pre amp. Currently I have Gustard R26 non tube dac do use tube stage on Frey’s with nos tall boys. I still hope to some day find the holy grail Telefunken nos tubes and not have to pay a $1000 each. Have fun exploring and enjoy the music!

The DAC is your source.  So if you want your system to sound the best it can, get the best DAC you can.  We prefer tubes so that is our bias.

Happy Listening.

@bigkidz What is the link to your company's website?

@macg19   I saw you recently added a Black Ice tube DAC into your system and mentioned rolling in Mullard tubes to really increase it's sound/performance.
I've been struggling with finding the right tubes for my Black Ice: the balance of 'quiet' vs tonality.  Can I ask where you got your tubes at?  Any issues with noise/microphonics? 

@amtprod I got the Mullards (and others) from Brent Jesse. Go to audiotubes.com

Brent is a guru, let him know Ian sent you (wont save you or me any money but it would be nice)

Best way to get a hold of Brent is email. He is busy and short handed.

The Mullards were expensive, $450/pair (1950s halo getter long plates).

Brent also recommended "Brimar military CV4035 “flying lead” 12AX7 modified by Bob Hoviland for use in a 12AX7 socket". I think these are $350/pair.

I have relatively cheap Brimar’s in my tube amp and they are wonderful - I’m a/b testing these against a much more expensive Mullard’s right now and so far the cheaper Brimar’s are better but I have many hours to go before making a call - the Brimar’s have a lot more hours on them than the Mullard's.

Dave from Raven Audio also suggested Amperex & Valvo (ECC83). Brent has these and lists all prices and in-stock items online.

These tubes were recommended specifically for the DAC - ZERO noise / microphonics.

Brent will allow a trade-in if you dont like what you get - no re-stocking fee if you apply the full purchase price to another tube.

I’d give the Brimar’s or Valvo’s a try first.

@amtprod Now I'm curious what tubes you tried and didn't like.

Just got notification that the Ayon Kronos ships out tomorrow! Super stoked.

Personally I prefer a DAC's fixed output if it has any type of attenuators.   Even better is no variable output at all.   My DAC is the excellent sounding LAB 12 DAC 1 Reference.   Sure it has no features to speak of other than input selection and has a fixed analog output using a pair of 6922, but it sounds phenomenal .  

@macg19 I have a pair of Gold Lion and a pair of RCA Long Grey Plate aside from the stock ones that came with the DAC.  The Gold Lion weren't anything even remotely noticeable in difference.  The RCA I like the sound of, but there is a bit of break up and they are VERY microphonic so I can hear odd harmonics and noise level.  Nothing I have tried yet has 'warmed' things the way I'd like, without making things smooshy.  I have a pair of Legacy Studio HDs (recent version) and a Rega integrated amp, so there plenty of detail and accuracy, but things are a tad 'edgy' and can be fatiguing after a while of listening.

@amtprod I've tried the Gold Lion re-issue power tubes and pre-amp tubes and they don't do anything for me either. The RCA grey plates are not cheap, so perhaps there is an issue with the tubes. "Edgy" is exactly what I was trying to get rid of, and I have. 

Very happy with the Black Ice now...it is NOT the DAC (at least not in my system). 

It is not as simple as people think. Just because a dac outputs enough to drive an amp to full power or more we are forgetting that we almost NEVER listen at full output power. Instead we listen at levels close to 1w or so which in terms of DAC output signal is VERY low signal levels. Unfortunately most DAC’s and CD players place the volume pot after the gain blocks which drastically raises output impedance when used at volume settings less than 100% and gets to an insanely horrible situation at the 10 to 20% of full volume that listening levels demand.

Preamps are made specifically to give optimum performance at these greatly attenuated listening levels and do it with authority. This is the major problem with passive preamps and they lack dynamics and bass drive. Unless the DAC is designed a certain way to optimize very low signal output it will suffer.

Regarding a tube dac used with a tube preamp, it is wonderful IF you have a great tube preamp. Unfortunately there are a lot of cheaper tube components that use tubes in starvation of low plate current for a very "Tubey" sound. That is not my flavor and a proper tube design has transparency, purity and lack of grain that SS rarely achieves.

@dht4me 👍

I’m totally on board with the idea that a tube dac can work well with an excellent preamp. I’m currently using an Aqua La Scala with my ARC REF6 and have no issues.
As far as tubes go- I’ve had great luck following the advice given from Brent Jesse. I’m currently running NOS Telefunken red tips w/ wing shape plates- great tubes!

Doge 7 Tube DAC is great. Have owned, Dac 1, Berkeley Audio, Hegel, Chord, MSB and more. This one sounds the best by far.

I've never had a tube DAC, per se (where the tube amplifies signal). But I have had tube buffers, both external and internal to a DAC.

In my experience, a well designed and implemented tube buffer can add to the sound quality of a DAC, especially when the stock tube is replaced by the best quality NOS tube available for that design. In my current DAC, the MHDT Labs Orchid, the stock buffer tube is a GE JAN 5670W. Well after overall burn-in was completed, I got a nice sonic bump by rolling the stock tube to a WE396jw. But when I got an adapter that let me use a Mullard CV5331, that was sonic paydirt.

An already very good sounding DAC got even better.

So I'm a believer in tube buffers...

Right now, listening to Qobuz through Bluesound to Musical Paradise tube dac to a Yaqin tube integrated to a pair of Forests,(secondary system). I wouldn’t have thought I’d be getting the sound I’m getting with such components but there’s amazing frequency range, plenty of depth and air, it’s amazing. No rules.

If you can run a tube preamplifier with tube amplifiers then why not a tube DAC? Makes sense to me, although I have not heard that combo but my gut says it should sound great. Of course synergy between manufacturers will always be an issue to be aware of, so if the first pairing does not work out well keep trying, I am confident you will find that correct combo that brings heaven.

@axo0oxa You miss the point. As the thread above has clarified, a tube DAC (or any DAC) with volume control can be used as a preamp in itself. So the OP asks, is you have a tube DAC and like tube sound, why bother using it simply to feed a tube preamp? The overwhelming answer is (a) results are better running any DAC, tube or SS, through a preamp rather than direct to amp; (b) patrons of tube sound prefer tube DACs with their tube preamps, and there is no reason NOT to use this combination as most devices are compatible.

@hickamore I believe this is what I was responding to which is what he wrote:

"So, question: am I wrong to suppose that pairing random tube DAC A with random tube preamp B is a bad, or at least a silly idea, absent a known synergy?"

Pairing a tube DAC with a Tube Preamp a bad thing, so I responded to that.

The problem is the output stage of a DAC is usually just a buffer, it doesn't have gain like a preamp. There are tube preamps out there that incorporate a DAC, then it has a real tube preamp.

Review of the LAB 12  DAC 1 Reference 

I have had this DAC since June , with the option to trade up in a year to something 2 X the price.    This is a great DAC,  so good that I am going to hang onto it for a while.