The tubes in all digital equipment are in the final gain stage.
It is similar to using a tubed preamplifier.
Though the small tube compliment, and cheap power supply in all the tubed DACs are more equivalent to various small tube buffers offered for sale.
I own a TADAC tubed DAC but i use an Adcom AD700 for most listening to digital, via a tubed preamp I call my glorified tube buffer.
What i would say is the minimal tube compliment in all the 'tubed DAC' are not enough to actually give a quality sound.
One would be far better buying a decent tubed preamp for the 'tube'yness' function.
I generally prefer tubes when it comes to amps and preamps. With source-DAC/CD players I find SS vs tube far less important compared to the overall implementation. A good SS discrete output stage,no negative feedback and with a robust power supply can sound as good or better than a tube output stage. Execution seems to matter the most.
Modwright Transpoter is an excellent, versitle, fun tubed dac.
Strictly a personal preference kind of thing.
Liz's right. there are no actually tube DACs. They all only have the tube gain stage. The logic part is done by DAC IC and that's where most of quality depends on.
I believe sound quality mostly depends on the output stage and power supply quality.
A while back I purchased an Audio Research DAC8 strictly on the premise that it sounded better than any other I'd heard, design concerns aside. Before I purchased it I had a long conversation with a fellow at A.R.C. I asked him why they stopped using tubes in there newest DAC, he said they built and tried both technologies for there latest DAC, but the all solid state unit just sounded better to everyone there.
"and cheap power supply in all the tubed DACs"
So if you are insinuating that this is true of ALL tube DACS, I call BS on it.
I agree with you, there`s no way you can generalize that way at all.Tube and SS DACs both run the full spectrum from poor to exceptional in regards to power supply quality.
Yeah, that's just Elizabeth painting with that broad brush of hers again. Nothing new to see here......
My sense is that Liz and Marakanetz may be making a fair point. I used to own the ARC Ref CD-7 with upgraded power supply. Some called it the Ref CD-7.5. I recently bought the Ref CD-8. To my untrained eye, the innards of the CD-7 and CD-8 look very similar. The main difference is the DAC IC. The CD-8 uses a Burr Brown DAC. The CD-7 uses another type of DAC -- I forget the name. To my old ears, the CD-8 simply sounds better than the CD-7. I found the CD-7 to be bottom heavy and thick. The CD-8, by contrast, has more air. The bottom end is less viscous than the CD-7. I attribute the difference to the DAC -- not the guts. Can't speak to other ARC DACs, like the DAC 8, but I think I make my point. It may very well be that in the case of a DAC or CDP source device, the DAC IC is the main driver of sound quality versus a SS or tube gain stage -- don't know. But I can report that the DAC in the Ref CD-8 sounds better than the DAC in the CD-7. My sense is that the innards are less critical. FWIW and IMO.
An interesting comparison might be how the ARC CD-5 compares to the REF CD-8. Both use the same DAC. However, I believe the CD-5 is pretty much all SS versus the CD-8 which has a tube gain stage and tube regulated power supply. If anyone has critically compared the two CDPs, please chime in.
By your premise, Elizabeth is wrong. She points to the crappy PS in "all" tube DACs being the cause of "inferior" sound. You point to the DAC. You don't help her case at all.
Shakey, I may stand corrected. Perhaps Liz and Marakanetz can clarify their posts. I echo what I said about the DAC IC -- it's critical to sound quality. But at least in the case of ARC gear, the innards, including power supply, are based on the landmark Ref 3. In no way would I concur that ARC went cheap on their CDPs.
I have heard that ARC may be going the straight DAC route at this point. I am not aware of a CD-9 coming on line, but I could be wrong. The CD-8 is almost 4 years old. That's generally when ARC rolls out a new product. It may be that ARC is of the view that redbook CD has run its course and it's time to go the DAC route. Just speculation my my part.
The DAC chip is important(no arguement) but 'many' various brands of CDP/DACs use the same chip yet sound vastly different.The notion that'all' tube DAC/CDP have subpar power supplies is just incorrect.
I have heard tube and non tube designed DAC and cdps that sound good. For years my digital playback of choice was a Tube Research Labs modified Sony universal player. Not a tube in sight, but wonderful sound. It actually replaced a player with a tube output stage.
Now I have an outboard DAC with a tube output stage. It sounds great and replaced the TRL Sony. I agree with Charles1dad. It's more about the implementation than the sum of the parts. To my way of thinking, the PS and analogue stage is more important than the DAC chip.
can i deduce from the posts i have read, that regardless of tube selection, if there are problems in design, the tube cannot overcome them ? for example, an inferior dac chip can not be ameliorated by selecting the right tube.
Denon 5900/ModWright, Metrum Octave.
I auditioned six other under $600-$2000 DAC's before settling on the Octave. Without getting into the brands the other six DAC's were of generally traditional design with a non tube output stage.
To varying degrees some offered improvements in detail and transparency over the Denon player as well as using the players optical output via Van Dan Hul Optocoupler MK II > DAC, bypassing the the ModWright tube output stage.
In all cases I enjoyed listening to the player regardless of the varying loss of detail and transparency.
Right out of the box the Metrum Acoustics Octave Non Over Sampling DAC with its chip based output stage delivered all the detail and transparency of the best of the six also rans but with a rich lushness and shimmer that is as easy to listen to as my analog.
I need to be clear here. It's not the same as analog but it's the first time in my limited experience were digital became as easy to listen to as an LP. And this from Pure Music 96kHz output through a wireless connection to a Squeezebox Touch.
Once again I'm convinced that as with using a tube preamplifier as a tone control for some class D amplifiers the use of a tube output stage on my player is simply a band aid or filter for the poor execution of its digital conversion.
"The application of technology is what is important. It can produce brilliant or poor results depending on its implementation."
Jeff Rowland, The Absolute Sound May/june 2012 Issue 223 pg 71.
For the clarification DAC device is far more complex than output device. To make a good quality output device for budget is far more achievable than same with DAC device.
I am using the AMR DP-777 now and the sound is stunning right out of the box. I understand that after 500 hours it really comes into its own.