DAC audible differences are finally proven with ABX?

[jabbr]

The good news is that sampling theory is 100% mathematically proven. It doesn't require statistical testing or supporting evidence to back it up.

Which can be a refreshing thing now and then...

Traditional sampling theory requires strictly linear processes ... that's the bad news. The systems being discussed aren't strictly linear. How well do you understand nonlinear sampling theory e.g. https://www.weizmann.ac.il/math/yon...lications/Nonlinear and Nonideal Sampling.pdf

 

[AndyBell]

In all fairness Josh did not seek scrutiny and did not post his findings here.

Sorry, but he posted on a public forum where subjective views are welcomed and, from the threads I’ve read, are guarded - see one thread on cables and the first post tells objectivists not to post on it!

Posting it publicly is to invite scrutiny.

Subsequently resisting that scrutiny is disappointing, to put it mildly.

 

[amirm]

One can simply ignore the results based on missing info and controls and independent checking or embrace the idea that even considered good sounding DACs (that sound very similar in normal circumstances) can possibly be identified audibly.

That is not the borders of this test. Lack of controls is outside of vocabulary of many who say just about every DAC above SINAD of 80 sound the same. If someone says they do sound different, they are told to do level matched, double blind test. Well, the author did that and if that was our only ask, it is more than satisfied. We can't just now be whistling dixie and say all is well because he didn't use controls. We don't know if those controls show anything. We also have doubts about the comparator but again, we don't know if that has done anything. The net result is a strong, very strong counter to routine posts I see as I mentioned above.

The only counter we have, which is a strong one, is unwillingness of the author to let us examine his work. But he has now offered to sell me his comparator and asking how much I would pay. How much should we/I pay? Seeing how members are building a much better version, it has no long term value for me other than investigation of this issue.

 

[Buckeye Amps]

How much should we/I pay?

How much did he pay?

 

[amirm]

How much did he pay?

I don't know. New they were going for $1,000 I think. I imagine the person selling it charged less.

 

[solderdude]

Why buy one ?

Erin has one and all that needs to be answered is how much distortion the level matching circuit adds and how the switching is.
I'm sure he is more than capable to provide that info.

 

[Buckeye Amps]

I don't know. New they were going for $1,000 I think. I imagine the person selling it charged less.

That's way less then I thought considering how against shipping it the owner is.

I'll chip in for a portion if a fair price is agreed upon.

 

[hardisj]

Why buy one ?

Erin has one and all that needs to be answered is how much distortion the level matching circuit adds and how the switching is.
I'm sure he is more than capable to provide that info.

I have this on my to-do list. Currently I’m steeped in clothes shopping with my teenager for school. Hopefully tomorrow I’ll be able to finish up using the ABX for the current review I’m working on. Photo below.

Once that is finished I’ll move the ABX to my office to get some measurements. I will be in North Carolina next weekend for the Audio Advice live show.I’m shooting to have the ABX data posted before I leave. But I can’t guarantee it between my day job, family and other personal interests.

TL;DR
I’ll provide the data. The group here just needs to be patient.


EDIT: But let’s not forget. It’s possible - not probable - that Josh’s unit could somehow measure differently than mine. So there is still the potential that any issues with his testing wouldn’t be shown by measurements of mine. I’d be extremely surprised if it were, though.

 

[Sokel]

That thread is so unfortunate, and sadly not about the test.

There are impossibilities around, mostly about the gear needed.
We suppose to make it easier, right? We ask people to perform tests like that all the time, conditions are almost like a mantra.

Now seriously, can anyone in the right mind believe that these conditions will be ever met? Did anyone take a look a the "ideal" comparator thread to see what it takes?
Any single objection there will very well stand in any test.

Proper ABX is already a marathon done right, adding a decathlon on top of it is not a good picture.
Purely technical, the task as described is close to impossible for a comparator (10dB better THD+N that the DUT and that with all the systems to report back, etc) that meets all the conditions and automatically reports, and, and, and...

It's becoming as boring as the bin thread

 

[JustAnandaDourEyedDude]

That is not the borders of this test. Lack of controls is outside of vocabulary of many who say just about every DAC above SINAD of 80 sound the same. If someone says they do sound different, they are told to do level matched, double blind test. Well, the author did that and if that was our only ask, it is more than satisfied. We can't just now be whistling dixie and say all is well because he didn't use controls. We don't know if those controls show anything. We also have doubts about the comparator but again, we don't know if that has done anything. The net result is a strong, very strong counter to routine posts I see as I mentioned above.

The only counter we have, which is a strong one, is unwillingness of the author to let us examine his work. But he has now offered to sell me his comparator and asking how much I would pay. How much should we/I pay? Seeing how members are building a much better version, it has no long term value for me other than investigation of this issue.

I think it is worth only two cents each from those willing to help buy it, and mine are that we should not buy Josh's copy out of a burning itch to get to the truth of what actually happened with this particular study.

What if it turned out the comparator Josh used is not a problem? Then we would be still be stuck to find out what really went on. If on the other hand, you find some audible tells due to operation of the comparator, Josh may continue to attribute his ABX results as due to discriminating soundstage, etc., and we still would not have settled the matter. Later, Josh # 2 in Australia or Singapore or South Africa or elsewhere may publish a similarly flawed study as fact. Would we rush to get to the bottom of that, too?

Josh published a study with an inference as purported fact. He provided strong ABX listening scores, but insufficient actual electronic signal checks. In this thread, ASR experts have pointed out the shortcomings and possible remaining stumbling blocks of the study, and all these objections are on record now in nearly 700 posts to date, for anyone to see. This is the equivalent of publishing a "letter to the editor" by someone pointing out mistaken results or methodological loopholes in a published paper, and normally this is all that is done in scientific dissent. The onus is on the authors of any scientific study to prove their conclusions satisfactorily. As you have pointed out, Josh should have checked with technical experts before publishing (when he was just beginning to score well on the ABX tests, ideally). But he was confident enough in what he was hearing to proceed with the tests, and publish the study. The circles Josh moves in will likely see the study as methodologically acceptable.

I think we are better advised to patiently wait it out for Erin's input and the efforts of other ASR members to shed more light on Josh's case.

 

[amirm]

I think we are better advised to patiently wait it out for Erin's input and the efforts of other ASR members to shed more light on Josh's case.

Certainly Erin's testing will go a long way toward getting what we need. That said, it won't be a complete picture because he is not me and doesn't have infinite time and motivation to get to the bottom of this.

What we are looking for here is channel differentials, tells, etc. Some of this testing would not even be measurements. Some of it involves running it against the DAC tested which I believe I already have or can easily get.

So all else being equal, I like to get access to Josh's box. I am game for $250 but i suspect he wants more. I am happy to rent it for that amount and then send it back him. Not sure if he likes this or not.

 

[Salt]

Certainly Erin's testing will go a long way toward getting what we need. That said, it won't be a complete picture because he is not me and doesn't have infinite time and motivation to get to the bottom of this.

What we are looking for here is channel differentials, tells, etc. Some of this testing would not even be measurements. Some of it involves running it against the DAC tested which I believe I already have or can easily get.

So all else being equal, I like to get access to Josh's box. I am game for $250 but i suspect he wants more. I am happy to rent it for that amount and then send it back him. Not sure if he likes this or not.

Will you honour this box, rented at this price, or wait a moment to offer him the ASR box for rent, that is just in R&D, but certainly supreme?

 

[Buckeye Amps]

Certainly Erin's testing will go a long way toward getting what we need. That said, it won't be a complete picture because he is not me and doesn't have infinite time and motivation to get to the bottom of this.

What we are looking for here is channel differentials, tells, etc. Some of this testing would not even be measurements. Some of it involves running it against the DAC tested which I believe I already have or can easily get.

So all else being equal, I like to get access to Josh's box. I am game for $250 but i suspect he wants more. I am happy to rent it for that amount and then send it back him. Not sure if he likes this or not.

I'll match what you put in if it is the only way to get it to test. My curiosity is peaked

 

[Talisman]

I urge you to consider that even if Josh were a troll (note: I'm not advocating it, and I don't think so), he would have hit the bull's eye, a community in turmoil, the first of many eager to learn more, as well as a well-known amplifier manufacturer.
The test results are surprising, but we were unable to validate them due to the information that was deliberately withheld.
At this point, I'd file this issue away like any other anecdote about my cousin.
If and when Josh eventually wants to address the issue, he already knows what data to provide.
Until then, for me, it's a pointless discussion.

 

[gzost]

Put me down for 100 USD should a decision to buy be made.

 

[Plcamp]

I suspect that even if you did get Josh’ machine, and (however unlikely) it then tested transparent…that would still be insufficient for a deterministic explanation. There are questions beyond the scope of the ABX hardware alone.

So it’s questionable why one would attempt to obtain it.

A better approach would likely be to run an independent, well monitored ABX test on the same dacs with many listeners … that resulting evidence would be directly comparable to Josh’s conclusions.

 

[amirm]

It would get rid of multiple variables in discussion right now so has value.

 

[pablolie]

Put me down for 100 USD should a decision to buy be made.

I offered up to 3k before. that's not the issue.

 

[donjoe0]

Human physiological hearing limits exist; individual differences can only occur close to those limits

Yes, that's the topic. And one gaping hole I see in the denier side's arguments on this type of DAC controversy is they do not actually know what the limits are for the human ability to detect deviations from a perfectly flat FR. Yet they behave as if this was as clearly established as our inability to see UVC or gamma-rays, or hear 40k, and they proceed to hammer strangers over the head with this illusion of established knowledge.

 

[NTK]

Yes, that's the topic. And one gaping hole I see in the denier side's arguments on this type of DAC controversy is they do not actually know what the limits are for the human ability to detect deviations from a perfectly flat FR. Yet they behave as if this was as clearly established as our inability to see UVC or gamma-rays, or hear 40k, and they proceed to hammer strangers over the head with this illusion of established knowledge.

Read this.

https://www.researchgate.net/publication/279594319_The_Modification_of_Timbre_by_ResonancesPerception_and_Measurement