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?

 

 

 


4cd89561 9834 4bd2 9434 13dd183d0702Ag insider logo xs@2xzimmerma

Obviously you are going to get a lot of questions about your other equipment, with the implication that it might not be 'transparent (good) enough' to show the differences in sound quality between your DAC's. Others will wonder about your choice of music, or file quality, or even your musical listening skills.  Not that all these points are irrelevant :-) 

However, based on my own (admittedly limited) experiences comparing DAC's, these are probably the most snake-oiled products in audiophiledom. There are differences, sure.  But the night/day hyperbole routinely gushed about and the astronomic prices being charged are extraordinary.

To my surprise [and disappointment], the sounds from the two DACs were utterly indistinguishable
 I take it you were only playing PCM RedBook cd?  

Cheers George
That's why audiophile should spend 60% budget on a good pair of speakers, 30% on amps, and 10% on CD (DAC) players.
I appreciate your comparison and since that Denafrips is obviously way over priced I would be happy to take it off your hands for a meager sum. ;-)
It's all about resolution and fidelity with a DAC. If your gear can't reproduce it, it won't make a difference. A 10k$ DAC sounds the same as a motherboard's through the garbage packaged with your iPhone. Not commenting on your gear, just that the effects are extraordinarily subtle and the differences require extremely sensitive instrumentation to detect.
Your pre/amp might be imposing the same character on both? I’m doing the same now I have an R2R DAC that I’m auditioning against a Rega DAC R and there significant differences, working through extended listening to understand the differences.
I've compared Denafrips Terminator and Oppo 205 previously.  Denafrips products require long break-in time, for Terminator, it's about 3 months of high usage.  When I had the Terminator, it sounds the best when using coax connected to a good CD transport (not Oppo 205, no AES/EBU output).

I suggest you use your transport AES/EBU output into Pontus.  Let the Pontus breaks in before you do any serious comparison.
Thank you for this A/B test. More of the same please. I have myself still to hear a significant, or should I say interesting, difference between two alright dacs. Why spend 200 hours trying to find the smallest difference when you can change speakers and have a totally different presentation in five seconds? At least I'm not there yet and will probably never be (too little time and too many speakers....). Open to suggestions though.

Bought a used Forsman D2-10 yesterday. Happy weekend :-)
The proliferation of DAC's is a clever marketing ploy to get the insecure and gullible to spend more money. The same goes for IC's and power cords!
If DAC's really did sound different there would have to be some X factor that is responsible. Since the arrival of CD's and players in 1983, no such X factor has been identified. 
All well-designed CD players and DAC's measure essentially the same. The oddball ones that use tube output stages are of course subject to the higher levels of noise and distortion typical of tube circuitry.
Spending money on a new device is a powerful incentive to believe that the new device is somehow "better".
I can only say that I don’t need more than 10 sec to hear the difference between my Hegel HD12, LAB 12 DAC SE and through my Audiolab 8200CD:s own DAC.
I thank the Forum members who have responded to my “Comparison of DACs” post. Here are some comments:


Janehamble aptly suggests that I should specify the music, file quality and equipment I used with a possible word about my “music listening skills.”

 

Music [all on redbook CD]:

·    Large ensemble jazz: Eberhard Weber, 
“The Colours of Chloe,” ECM.

·    Piano jazz: Jean Beaudet, “Seul au Piano, Elephant Records.

·    Large ensemble classical: B. Bartok. “Concerto for Orchestra,” Charles  Dutoit, EMI.

·    Small ensemble classical: B. Bartok, String Quartet #6, Emerson Q, DG.

·    Pop/jazz vocals: Billy Childs, “Map to the Treasure: Reimaging Laura Nyro,” Sony Masterworks.

 

Equipment… First Test:

·    Transport: Nuprime CDT-8 [one test NOS, another OS @ 96Hz].

·    DACs to be compared: Denafrips Pontus, OPPO Sonica.

·    Preamp: PS Audio PCA-2 with HCPS power supply--- For the RCA inputs comparison

·    Cables: PS Audio

·    Amps: Anthem MCA 20

·    Speakers--- one test: Emerald Physics EP 2.8, another test: Magnepan 1.7. 

Music listening skills:

·    It’s not for me to say, is it?

 

Equipment…Second Test:

 

Everything the same, except for---

·    Preamp: Wyred4Sound STP SE--- For XLR inputs comparison.

 

georgehifi wants to know if I limited the test to PCM redbook CD.

Yes, in the test described in the OP… But later I did a test involving 2 different DACs fed by Spotify/USB. I’ll describe that later.

 

junzhang10 maintains that one’s budget should be allocated

60% on speakers, 30% on amplification and 10% on CD players, DACs. 

I am starting to agree with this.

 

falconquest insists that the Pontus is way overpriced and generously offers to take it off my hands. 

I shall have to think about this. Thanks, falconquest.

 

ethan_bennettstresses the importance of “extremely sensitive instrumentation” to detect “the extraordinarily subtle” differences between DACs. 

I do not doubt the importance of using good equipment with any DAC. However, I am starting to doubt that those “extraordinarily subtle differences” really exist. Thus the OP.

 

musichead speculates that my preamp may be “imposing the same character on both [DACs].”

Perhaps he would like to explain how a preamp can perform that sonic feat; and, even more, how such uniformity can be imposed by two different preamps [the PS Audio and the Wyred4Sound] in two different tests. Interesating.

 

anwar has beat me to the punch already by conducting a comparison of his Denafrips Terminator [lucky man] and his OPPO 205. He opines that my comparisons would be more valid only after the Pontus has had a chance to break in for a few months.

Re test: What were the results of your comparison, Sir?

Re break in: One does not want to awaken needless controversy, but the whole idea that electronic equipment requires break in time seems to be…. Well, open to doubt. But I have no axe to grind; anwar may be correct. 

 

gosta and roberjerman find the reported results of my tests plausible.

That encourages me to think that I am not going crazy. 

 

simna needs only 10 seconds to hear palpable differences between two of his DACs.

It would be interesting to learn more about the test conditions and the nature of the dramatic differences.

 

A bit more of FWIW--- another comparison, this time with Spotify Plus as the source, via USB.

 

Music:

·    Essentially the same as above.

 

Equipment… Third Test:

·    DACs to be compared: Denafrips Ares, Audioengine D2 [BB PCM 1792A-   DAC].

·    Preamp: PS Audio PCA-2 --- For the RCA inputs comparison

·    Cables: PS Audio

·    Amp: Talk Electronics Toronado 2.2.

·    Speakers--- Martin Logan Spires.

 

Result of comparison--- The same damn thing: Two differently configured DACS [R-2R vs delta-sigma] sound exactly the same from a streamer via USB.

 


This is really eye opening to me, I was planning to trade my Oppo Sonica for Metrum Onyx R2R DAC. Thanks OP!
I’m one who could be inclined to question the capability of the supporting equipment. I’ve heard plenty of differences between DACs and other components.

I’m sure you can identify the poster that sticks to a dogmatic opinion about the impossibility of differences between components. Julian Hirsch Jr. Always beats the same drum.
Hi jaybe. What makes you "question the capability of the supporting equipment"?
Resolution and transparency capability. The PSA is a 20 year old design, in those days PSA was considered pretty good mid-fi. The amps, while nice, are nothing special. No offense intended.

These are just my opinions and I have no stake or real interest so am not getting into any debates about it.

Just that I know that DACs do differ and the differences can be heard when conditions are right.
To to jaybe again...on a less defensive note:

What sort of "supporting equipment" should we base a comparison of DACs upon?

And when you heard "plenty of differences between DACs," what precisely did you hear?

Thanks.....OP


Thanks, jaybe.... What makes for the right conditions?
@zimmerma

I didn’t mean to be a smart arse, but the difference between Hegel HD12 and LAB12 DAC SE is pretty easy to hear. Especially when it comes to vocals where HD12 in comparission is harsh and cold.
Hi simna... .I did not take you to be a smart arse.... Not at all.
I just do not know the two DACs you mention, except to note that the LAB12 has a tube in the output section and the Hegel does not, so maybe that makes for the noticeable difference you hear.
Single most important factor when testing is the volume. Needs to be within +/- 0.2 db. Sometimes a problem with stepped volume controls.


To jaybe again....

No offence taken re your comments on my PS Audio PCA-2 preamp [though I think that Paul Gowan really would bristle at the "mid-fi".... and I note that the other preamp employed, the Wyred4Sound STP SE, is a current design], nor on my Anthem MCA 20 amps.

 .... And I do not really want to get into a tussle [here, anyway] about whether there are dramatic differences amongst preamps and amps....

I thought that the point of an A/B comparison of DACs would be to keep everything else in the signal path constant, as long as a decent level of electronic quality was maintained, not necessarily to use the latest and most expensive preamps and amps. 

The questions to you are, I guess, these:
  • In order to get a realistic and accurate comparison between DACs does one really need to use the the latest and most expensive preamps and amps?
  • Would that be the only way to reveal audible differences between DACs?
Thanks for your comments.   
To gosta:

You are so right about the importance of maintaining the same volume control across the comparison---
This is pretty easy to do by... 
  • keeping XLR/XLR and RCA/RCA input switching constant from the preamp during the A/B comparison, and 
  • leaving the volume control set at one point, and just switching from one DAC input to the other. [Actually, I had my wife do it, to retain that "double-blind" aspect of the tests.] 
Thanks, gosta, for making the point about volume control explicit. I should have mentioned it in the OP?
@zimmerma .. I’ve not heard your DACs in particular but I can hear distinct differences between the 4 I have, which includes both R2R multibit and delta/sigma types. (There is a small part of me that wishes I didn’t hear said differences to be honest.) I’ve found the A/B quick-switch method doesn’t reveal DAC nuances nearly as well as a lengthier listen. For me, a relaxed non-focused listen allows me to hear the subtle differences and, once heard, I can never un-hear them. Said differences are then not so subtle. DACs, as you put it in your op, offer differing flavors. I have 4 DACs because I enjoy change.
wtf
... I've found the A/B quick-switch method doesn't reveal DAC nuances nearly as well as a lengthier listen. For me, a relaxed non-focused listen allows me to hear the subtle differences and, once heard, I can never un-hear them ...
I agree and think it's true of not just DACs, but audio components in general. That is why I find the concept of an audio "shoot-out" (as some promote here) to be so useless. That's not to say that quick A-B switching has no value at all, but it isn't the best way to evaluate an component by a long-shot, imo.
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.
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. 

@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.


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. 
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. 
Folks sell digital data stream reclockers to reduce or remove jitter. Try one for the digital stream output from your NuPrime CDT-8 Pro transport. That might help clarify how well the two DACs perform when compared.

Try shooting a pm to Steve Nugent of Emperical Audio. His member name here is audioengr. 

https://www.empiricalaudio.com
zimmerma regarding having the volumes match its not just about having the volume know in the same setting. Dacs can have different outputs one Dac say an 2v output another a 3v in that case the 3v output will sound louder at the same volume setting. You really need a db meter to verify the loudness match.

Also I personally would suggest, if you can, changing up your methodology. What is often more helpful for me is putting a component in my system and listening to it at length weeks or even months. Then switching components listening some more at length and finally going back again. More subtle differences often become more apparent over time. As always just my opinion YMMV.
To celander:
  • Thank you for the datum on the Supreme CDT-8 jitter. I'll look into this aspect of my signal chain. 
  • Possibly changing transports or adding re-clocking would be in order. 

To jond:
  • Both DACs in the comparison have the same output voltage, 4v for the XLR outputs, 2v for the RCA. I controlled for that.
  • As for your interesting version of the earlier poster's "leisurely listening" approach, I tried to address that above, by noting that human "auditory memory" is probably not retentive enough to enable a very meaningful A/B comparison of components in a signal path. In my earlier response I referred to my own weak auditory memory, but is was just a weak attempt at false modesty; I really meant all human beings. Psychodynamic studies show that we just cannot remember enough about a sound series we heard as little as a few minutes ago to make accurate comparisons with one we are hearing now. [I'll dig out a study if I can. It's been awhile.]
Again, a general note a thanks to responders. I am finding these comments on my OP very useful.
A question for celander:
Where can I find the jitter rate of 190 psec that you quoted for the Nuprime CDT-8?
Thanks....
I thought this was first posted in a discussion of the CDT-8 over on AudioCircle, but a quick google search doesn't bring it up.
OP: The CEO of NuPrime (Jason Lim) provided that to me in an email. BTW, I just reviewed that email: it’s 120 psec, not 190 psec. We’ve had a rather spirited back and forth via email about the jitter number and the meaning of their “ultra-low jitter” and “extremely low jitter” language of their marketing materials.

To me, those language snippets mean different values to different folks. For the NuPrime folks, it’s 120 spec. For me, it means <5-10 psec.

The jitter value is measured at their output clock circuit. I have no idea what the jitter output is at the end for a 4 ft. coax digital cable.
Thank you for retrieving that datum, celander. Helpful.
  • Did you inadvertently reverse the "greater than" symbol in your second to last sentence, since 120 is larger than 5-10?
  • I suppose that Mr Lim would argue that any good DAC [perhaps his DAC-9 or DAC-10?] has on-board jitter reduction that substantially improves upon 120 psec from the transport output. Of course, that is no argument in favour of his specs vs those of transports with lower jitter output.
  • I do note, re my OP comparison, that both the Pontus and the Sonica do have substantial jitter reduction capabilities. I suppose that these days any good DAC does.
Best wishes......   
OP: I don’t believe I inverted any symbols. NuPrime thinks “ultra or extremely low jitter” means 120 psec. My interpretation of “ultra or extremely low jitter” is less than (<) 5-10 psec. That’s a big difference in jitter levels that affects SQ. Ask Steve Nugent (audioengr). I returned the transport to NuPrime after audition in my system, as it didn’t improve upon the SQ of my CAL Delta transport, which has less than 50 psec of jitter in the digital output stream. 

Whatever is in Jason’s mind of DAC compensating input jitter reclocking circuits is not relevant to marketing a stand alone transport. If he thought it didn’t matter, then why use marketing language regarding the transport’s jitter qualities? He’s trying to sell a given transport. If he wanted to, he could have pointed out any residual jitter could be reclocked by a suitable DAC having an input jitter reclocking circuit. His marketing language doesn’t point that out, however, for obvious reasons (red flags as to the transport having high jitter output). It’s possible that jitter is lowest via his transport I2S bus. But that is not really clear from his marketing materials, and his report of jitter values at the clock output circuit pretty much dictates jitter output for all digital outputs regardless of formats.

I’m not here to argue about a particular DAC’s input receiver having special associated reclocking circuitry. I merely pointed out that the Pontus DAC lacks the front end digital signal processing of Denafrips Venus and Terminator DAC’s. And that is why one pays a lot more for the top tiers of the Denafrips DAC line.

To celander:
  • I take your point about "compensating input jitter reclocking circuits." No marketeer of a stand-alone transport should rely on that point. "Stand-alone" means stands-alone, after all. 
  • I gather that your "back and forth" with Mr Lim was about the acal measurement of the jitter output of their CDT-8.... Yes?
  • You are quite correct about the difference between the anti-jitter capabilities of the Pontus, on the one hand, and of of the Venus and Terminator, on the other... Femto clock in the latter, not in the former. When I bought the Pontus I did know that.... but a budget is a budget.
Huge +1 to @celander -- especially if both DACs don't have very good reclocking built in.  It's pretty doubtful there is NO difference in sonic reproduction between these two DACs, so the question is why?  I agree with @celander that if you feed two DACs without a very good reclocker crap, you're gonna hear crap.  Whatever way you end up going, you might want to invest in an Emprical Audio Offramp to take jitter out of the equation.  
OP: I’m not going to go into depth of the banter between Jason and me other than to say he felt jitter at 120 psec was “low” although he suspected it was nevertheless inaudible. I disagreed with him, holding the position that jitter at any level above 10 psec was audible in terms of absolute SQ.

Steve Nugent and a parade of others agree with my view. The Jay’s Audio transport when inserted into my system confirmed this view for me.
I'm interested in the LAB 12 DAC SE.  Can anyone confirm if it has changed in any meaningful way since it was first produced in 2013?   
More than 10 years ago, when I could afford it, I purchased an MSB Platinum with upgraded R2R ladders, one in each channel, upsmpling to 384,  and a buffer to eliminate jitter. It sounds very good. I later got an Oppo universal NuForce player for 5 channel SACD and movies. I use the MSB for computer music from youtube and for DVDs. I read that the resistors in an R2R can age and lose some accuracy over years so that limits the practicality of the very expensive ladders.
I too find it difficult to tell the difference between the Oppo and the MSB Platinum in switching back and forth in an AB comparison.
Just be happy YOU and YOUR system gets to jump off the bus very cheaply, but do not rush to judgement that the same must be true for everyone as I can assure you it’s not.
I’m generally not one who responds on here although I often read people’s posts and the trail of comments. This one however is rather topical for me as yesterday evening my friend and I tried out a number of DACs , all of which we own between us. There was a difference in each and every dac that varied between levels of apparent detail, emphasis of different parts of the sound spectrum, image , Timbre , Tone , dynamics and added sibilance or absence thereof . We only used 3 pieces of music to keep the listening session short. Broadly you could divide them into acceptable and unacceptable. The ones that made the acceptable group where only two , one single AD1865 dac and the other PCM 1704 x 8 (4 per channel) and in this instance the output from the dac chips did not pass through an internal output stage but fed to the same 15x gain circuit located in the final output of my phono stage (obviously not the equalisation part!), and each one had its own differences, both acceptable but one just reached down deeper in the bass region and gave more spacial clues with stronger imaging , the other perhaps a touch polite. Now it absolutely depends upon your system , I mean what if the system did not go that far down in the bass region to start with then you wouldn’t notice that difference. 
Furthermore the output stage on the other DACs where probably more responsible for the sound than the DAC chips them selves- but that I’d have to do more work to prove that. If you find different then that’s fine we are all different 
I also very rarely write or post although I have read daily for 25+ years on various forums and have quite an array of “things”.

Emcdade hit it on the head.  My sentiments exactly, w/o being snotty and/or condescending... Really.  😉 Enjoy.
Hi emcdade:

Sorry, but if your post is directed at or to me, I confess that I can make neither head nor tale of it.
What are you trying to say?

Perhaps rootmann can explain, since he agrees so heartily.

Best wishes.....OP


So @zimmerma .. assuming (perhaps wrongly) you'll be ridding yourself of a DAC, have you decided which one? Pontus? Sonica? Just curious is all.