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A comparison between two DACs, one R-2R, the other ES 9038-based.

This is an item from the FWIW Department, I guess.

Recently I set up an A/B comparison between a Denafrips Pontus and an OPPO Sonica…. Both DACs fed from a Nuprime CDT-8, via the XLR inputs on the same preamp, and everything else constant through the two signal paths to the speakers.

The result when I repeatedly toggled back and forth from the preamp’s input one [Denafrips] to its input two [OPPO]?---- To my surprise [and disappointment], the sounds from the two DACs were utterly indistinguishable, across all kinds of music, after repeated trials … impossible to tell apart… impossible.

The moral of the story? I don’t really know, but it does suggest to me that those who say that DACs of comparable quality cannot be told apart just might have a point.

I bought both the Pontus and the Sonica because I thought that it would be nice to have on hand DACs of “different flavours,” one based on an R-2R ladder, the other based on a delta-sigma chip. 

I did want the expected difference to be real… just for the fun of it… else why spend the extra money? So, my “confirmation bias” was, if anything, stacked in favour of there being a detectable difference.  

However, the results of a reasonably well controlled comparison [sadly?] did not bear out that expectation. Differently based DACs, 2-R2 vs delta-sigma, may not offer such different flavours as many suggest. Is that claim all much ado about nothing?

Thoughts from members of the Forum?

 

 

 


128x128Ag insider logo xs@2xzimmerma
zimmerma's avatar
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zimmerma OP
102 posts
 
Very interesting, wtf. Thanks.
  • May I ask what the four DACs are?
  • Re your point about detecting differences via a "lengthier listen," I find that I have virtually no real "auditory memory" of the kind that would permit me to make any meaningful comparison between any two audio components across significant lengths of time, say, anything over a minute or so. Perhaps you simply have more retentive auditory memory.
wtf's avatar
wtf
307 posts
 
These are the 4 DACs I've held on to:

- MHDT Lab Pagoda (PCM1704)
- dB Audio Labs Tranquility (TDA1543)
- Chord Qute EX (FPGA bespoke design)
- Schiit Bifrost Multibit (AD5547CRUZ)

The Bifrost started its life as standard ds (AK4490) and was upgraded to multibit a few years later. I've had a couple other DACs as well but mostly lower-end ones. 

For me comparative listening is all about listening to music I'm well acquainted with. When I hear something slightly different I will A/B with another DAC or three (craziness, no?). I've learned a lot doing this over the years, hence my preference for R2R multibit. 

simna
165 posts
 
@zimmerma

Yes, there is a tube in LAB12 DAC SE but what about all the components, exept the chip, in the two DAC:s you have compared? Are they the same? Or do you mean using a tube is ”cheating” in any way? Every component in a DAC affect the sound. Doesn’t they?

So if you want to compare only different types of chips...I don’t see how that is done. But I’m not a technician.

Or maybe it’s because English is not my nativt language so I misunderstand you.


zimmerma's avatar
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zimmerma OP
102 posts
 
Hi simna...

Your English is fine....

I must say that I do consider a tube[s] in the output of a DAC a "kind of cheating," since tubes do tend to cause a second-order harmonic distortion of the original acoustic signal. I do think that this is no longer a particularly controversial claim. In any event, if you like the sound of a tube in the output, enjoy....

That said, I have to confess that for many years, I was a fervent fan of tube preamps--- Sonic Frontiers, Aesthetix, Audio Research, Conrad-Johnson--- for what I thought at the time would "soften" the sound of the rest of the signal path. I now think that I was very wrong.

Thanks for your comment. 
celander's avatar
celander
1,502 posts
 
The NuPrime CDT-8 Pro transport has a high jitter output (190 psec), which was far higher than my 1996 CAL Delta transport (<50 psec). The CDT-8 transport sounded unremarkable—clearly not superior to the Delta transport—when fed to my Theta DSPro Basic 3A R2R 20-bit, 8x oversampling DAC. 

I then aquired a Jay’s Audio CDT2 MK2 transport. Superb top-loader with ultra low jitter. Result when connected to the Theta DAC? Best Redbook CD playback ever from my system. Micro and macro dynamics, imaging, resolution and soundstage extended well beyond the offerings of the other two digital transports when combined with the same DAC. 

My take-home message is that the jitter-encoded signal from the transport likely contributes significantly to how well one can distinguish playback differences in the DAC, as well as whether the full potential of the DAC can be realized.

In my case, the transport made a huge difference. I suspect the same effect is taking place with your system, where a jittery transport over-rides any benefit afforded by the downstream DACs. 

I have heard a lot of good things about the Denafrips Pontus. I don’t know if it has the reclocking hardware of the more expensive Venus or Terminator. 
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