DAC audible differences are finally proven with ABX?

[Thomas_A]

I am not sure. The high input impedance of the buffer or the Scaler avoids loading of DAC output, but does not help with Cosmos electrolytic coupling capacitor value and LF distortion. This remains unchanged. Some cure is if you use higher Cosmos input range or series resistor with the input, for obvious reasons (capacitor CR HPF corner and distortion). But, then you lose resolution (input range sensitivity).

I am in fact not much interested in getting the lowest 1kHz SINAD. This is just good for the chart rating at the single frequency. But as you, me et al can see, we are fighting different issues. Namely FR flatness, ringing, LF phase behaviour. They all may become audible. NOT the 1kHz SINAD. No difference if it is -110dB or -130dB. Just numbers game and top chart race. This is interesting for producers to make a techno oriented marketing.
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To make it clear - I consider E1DA Cosmos ADC an excellent product, especially concerning its price/parameters value. But it has certain limitations and we are here not to create a cult, but to speak openly.

The scaler helped my measurements of my Muffsy Phono preamp though. Both a correct LF and reduced distortion.

With scaler:

Without scaler:

 

[pma]

The scaler helped my measurements of my Muffsy Phono preamp though. Both a correct LF and reduced distortion.

It reduces distortion in case of sub-optimal design of preamp or DAC output stages as it is loading them less. This is obvious and was several times mentioned here.

 

[pedrojoaquimborges]

As @pma said above, they started a thread with a very insightful comparison between a record and a version of it ran through DAC/ADC. Should offer some more perspective on this debate.

Josh's withholding of the test signals seems, to me, the fundamental problem underneath this discussion, since peer reviewing and replication of the study are effectively made impossible. Program material is infinitely varied and its specific characteristics are of critical importance to audio component testing. You could even argue that commercially recorded music is unsuitable as a primary auditory test signal.

However, I think the focus on clock drift and other timing issues might be slightly misguided. I believe a better methodology for audio abx testing involves listening to the full length of an excerpt, rather than switching between test files/equipment mid-playback. No matter how transparent the ABX device, program material changes so much along the time-domain that only the exact same excerpts should be compared (easy to do on foobar).

 

[pma]

No matter how transparent the ABX device, program material changes so much along the time-domain that only the exact same excerpts should be compared (easy to do on foobar).

That is the key! ... and I am sure you have known it for long. The consecutive switching between A-B-X when the music sample is continuously played would not give a result just for the reason you mentioned. There should be a selected short part that is played as a whole as A, B, X and then to decide what was X.

 

[pjug]

There's some entertainment "science" going on here. But hey, that gets those clicks, doesn't it.

Well, one side is trying to get at what Josh was hearing. Another side prefers to keep it as an unsolved mystery. Which sounds more like an entertainment program?

 

[Mort]

That's a nice "unscientific" approach. You know very well that those numbers have nothing to do with actual visits - they include bots. And how many visitors at each site have tracking blocking software installed? Not reflected here.

As a general comment on the thread, it's certainly possible there were "tells" in the test that Josh unknowingly heard. But I find it interesting that some of the "tells" being discussed here are things that in other threads have been dismissed as inaudible. Well, are they possible tells or are they inaudible? Are they inaudible when you agree with the results and audible when you don't?
There's some entertainment "science" going on here. But hey, that gets those clicks, doesn't it.

You should really just move along

 

[RickS]

Not sure. But I think it’s safe to presume that forum probably has a typical range of good faith, civil replies to snarky cheap-shot commentary, like this forum. I haven’t seen a forum that escapes this dynamic. Btw…don’t the mods here council restraint and keeping discourse civil? Is that concept suddenly out of style?

Could not pass this one up. The forum rules encourage professional behavior by members. The rule enforcement varies somewhat by thread. For example, the humor thread gets different moderation than a review thread. This thread falls somewhere in between. Also, even with more mods, there is way too much volume to monitor every thread.

So, in the end, the bulk of the responsibility for forum behavior falls on the members.

Fortunately, there’s enough good natured and informative commentary on ASR to rise above the occasional snark and make it a great place overall, which is why I (quixotically) defend ASR on other sites.

Thanks! Without driving towards professionalism and members encouraging good behavior, can see (and have seen) how challenging it might be on other forums. While am not surprised, few really carefully read the ASR Terms and Rules until something motivates them to do so. It is part of why we developed and have more exposure for the FAQs,

 

[MattHooper]

Sorry but that is the most likely, possibly the only explanation for someone getting 12/12 on a level matched DAC ABX

I’m curious: what would you make of some of my own results when I did a blind test between a Meridian CDP and a Museatex BiDat DAC? (and also a Sony CD player.)

The DAC had an outboard volume control, which made it easy to dial in the volume to level match precisely the outputs to 1.72v at the speaker terminals. I was able to identify the DAC from the Meridian CDP - 17 out of 18 guesses correct. The DAC vs the Sony CDP trials were shorter, but seven out of eight guesses correct. Meridian CDP vs Sony CDP: two trials, six out of six guesses, correct, 12 out of 12 guesses correct.

(please understand I’m not offering this up as proof anybody needs to accept… I’m just curious about what you would make of the above given your statement about DACs. And by the way, I’m with you that any well designed DAC should sound indistinguishable from another, and as I understand it, it’s not terribly hard to design a competent DAC…. Which is why I don’t really care about the difference in sound between DACs these days),

Cheers

 

[Mort]

False positive. I wouldn't like hanging out in a place where my beliefs are so disrespected.

 

[pma]

It is not a disrespect, really. It is about impossibility to verify if the test conditions were valid, if they met matching requirements. Such test is just valid and important only for the person who has passed it. It may be supported with a nice story, like @MattHooper e.g. can create, but the result is not transferable.

 

[MattHooper]

It is not a disrespect, really. It is about impossibility to verify if the test conditions were valid, if they met matching requirements. Such test is just valid only for the person who has passed it. It may be supported with a nice story, like @MattHooper e.g. can create, but the result is not transferable.

I can certainly see what you mean with respect to my tests being unverifiable beyond what I can report. And this is one reason why the feature of replication of results by other parties is important in science.

But along those very strict lines…. Is there any actual hope of verifying Josh’s results (presuming for instance people here aren’t going to have access to all of those DACs, and likely won’t be able to repeat the test)?

And if not… what do you think the goal is here?

I suppose if the ABX box tests wonky that would give good reason to doubt the results on that basis. But if it tests OK… do you ever get towards verifying the results?

 

[pma]

But along those very strict lines…. Is there any actual hope of verifying Josh’s results (presuming for instance people here aren’t going to have access to all of those DACs, and likely won’t be able to repeat the test)?

It depends who has what kind of hopes. I have read his test story and frankly, I am not much interested in his results, even if they were 100/100 success. The reason is, as I have mentioned many times, that his test conditions cannot be independently verified and repeated. His results are for himself and his community of followers. We might have had a chance if we had him recorded the music files from his test, which did not happen. So, speaking for myself, verifying of his results is impossible.

 

[firedog]

So are you saying that as Josh’s work was posted on that site, it is also non-science?

Just like this site isn’t science. Measurements aren’t science, they are one of the tools of science.
Don’t get me wrong, I think this site provides a very good and valuable service.
But it also isn’t the last and authoritative word on anything.

Josh’s work was a serious, well done attempt by someone who made zero claims of being a professional in the audio field or the last word. Very few here have ever done anything even remotely similar or involved.

He also made no claims that his results had wider meaning.
All of that was put on top of his article by people here.

People here have had, in part, a non-scientific and emotional response to his article.
The lack of self awareness of many posters here is astounding.

 

[firedog]

Well, one side is trying to get at what Josh was hearing. Another side prefers to keep it as an unsolved mystery. Which sounds more like an entertainment program?

False statement.

 

[firedog]

You should really just move along

Amir insists on comparing apples and oranges in the quoted site statistics.
Just one of several distortions and non-supported claims made by several posters in this thread.

 

[voodooless]

He also made no claims that his results had wider meaning.

He doesn’t have to. He put this out into the world for everyone to read. You don’t just do that if you think that it doesn’t have a wider meaning.

 

[amirm]

Just like this site isn’t science. Measurements aren’t science, they are one of the tools of science.

We apply science when we assess audibility of measurements. So while it is true that measurements are just technical evaluations, their analysis using scientific is very proper and what we do every day of the week and twice on Sunday.

Don’t get me wrong, I think this site provides a very good and valuable service.
But it also isn’t the last and authoritative word on anything.

We haven't said we are the last word. We routinely bow to the incredible work that top researchers in the field have provided us. We stand on shoulders of giants.

AS however, can easily be dismissed as having little interest in proper science and engineering of audio products. It is all the "trust me bro" culture of "I have said, so it must be right."

In other words, a huge gap between us when it comes to reliability of fidelity assessments.

Josh’s work was a serious, well done attempt by someone who made zero claims of being a professional in the audio field or the last word. Very few here have ever done anything even remotely similar or involved.

Actually, it could have, and can still be an important development. He just managed to screw the pooch from the start in thwarting our attempts at analyzing and understanding what he had done.

He also made no claims that his results had wider meaning.

He has in our book. If his results are correct, it has incredible impact in how we talk about DACs in the specific, and audio products in general. Him or you backpaddling is just a defense in case it turns out the results are not trustworthy.

All of that was put on top of his article by people here.

Not at all. We are not stupid. We can see easily when someone slaps you in the back of the head in front of you but then says he didn't do it.

You don't say I have these amazing blind test results but excuse me, I am a) too busy to help you understand it and b) give you anything tangible to analyze. I would have been his best friend in this thread if he had agreed to loan his ABX device to me. And others would have been overjoyed with access to captures he has.

By now you have seen numerous posts from him here and on AS. So let's agree (a) was a farce. And with us having to pay so much to buy his box, (b) was a farce as well.

Almost everything you see here is the results of his conduct, and frankly, the few of you defending him in such poor manner.

Really, stand on the side of getting to the truth. Don't give him cover like this (especially since it doesn't work). Tell him that he should have enabled us fully to replicate his results. After all, what could have been more powerful than our endorsement? And if we did find his results to be faulty, don't you want to know that instead of putting your head in the sand thinking they are good?

 

[amirm]

Amir insists on comparing apples and oranges in the quoted site statistics.

Independent estimates of traffic is the very definition of apples vs apples. I didn't show you stats from one site, and compared it to stats from another site.
But here is some hard data. On the home page of AS forum, you have this as the top left review:

3 comments posted since August 4th (it is the 9th right now).

Here is my recent review posted on August 7th for a device that is not core to what we are about:

36 posts.

Everything on AS home page shows very few posts except this one:

Which is courtesy of us.

So please don't bark up this tree. The business model of shallow reviews and forum discussion allows Chris to make a living from it but it is not a giant footprint in audio.

 

[Salt]

We apply science when we assess audibility of measurements. So while it is true that measurements are just technical evaluations, their analysis using scientific is very proper and what we do every day of the week and twice on Sunday.

We haven't said we are the last word. We routinely bow to the incredible work that top researchers in the field have provided us. We stand on shoulders of giants.

AS however, can easily be dismissed as having little interest in proper science and engineering of audio products. It is all the "trust me bro" culture of "I have said, so it must be right."

In other words, a huge gap between us when it comes to reliability of fidelity assessments.

Actually, it could have, and can still be an important development. He just managed to screw the pooch from the start in thwarting our attempts at analyzing and understanding what he had done.

He has in our book. If his results are correct, it has incredible impact in how we talk about DACs in the specific, and audio products in general. Him or you backpaddling is just a defense in case it turns out the results are not trustworthy.

Not at all. We are not stupid. We can see easily when someone slaps you in the back of the head in front of you but then says he didn't do it.

You don't say I have these amazing blind test results but excuse me, I am a) too busy to help you understand it and b) give you anything tangible to analyze. I would have been his best friend in this thread if he had agreed to loan his ABX device to me. And others would have been overjoyed with access to captures he has.

By now you have seen numerous posts from him here and on AS. So let's agree (a) was a farce. And with us having to pay so much to buy his box, (b) was a farce as well.

Almost everything you see here is the results of his conduct, and frankly, the few of you defending him in such poor manner.

Really, stand on the side of getting to the truth. Don't give him cover like this (especially since it doesn't work). Tell him that he should have enabled us fully to replicate his results. After all, what could have been more powerful than our endorsement? And if we did find his results to be faulty, don't you want to know that instead of putting your head in the sand thinking they are good?

Very polite and exhaustive answer, respect.

 

[Deleted member 93733]

People here have had, in part, a non-scientific and emotional response to his article.
The lack of self awareness of many posters here is astounding.

I have been following the thread on AS. The French have a saying, which translates approximately to, ‘whenever you point a finger, there are always three pointing back’.