External DAC with Connect

Can it be a blind a-b test also?
Were one doesn't know which is which?
Does that count?

No, it must be double blind. There are reams of scientific evidence that prove a single blind test is influenced by queues from the party who knows which is which. Which is why science insists on double blind studies.

But you already know this, because it has been discussed before. :rolleyes:

Can it be a blind a-b test also?
Were one doesn't know which is which?
Does that count?
Although ABX is more than that, I would say yes to your questions, provided both tester and tested don't know which is which - i.e. double blind.
Equally important and more difficult to do is level matching to within 0.1 dB of sound levels from each alternative being tested.

Far from it. Pick any two modern amps of different makes at any price point and different power outputs and these will fulfil the terms of statement 1 - provided that they measure alike in having a flat frequency response and close to modern levels of distortion, as most modern amps now do.
To amplify on the above - examples of amps that may be compared and will meet the assertion in statement 1 are current budget models from Marantz, Rotel, Nad and the like, Quad 99/909 pre power, a Krell 400 wpc, all the way to the USD 100k priced Audio Note Ongaku. With cheaper Luxmans thrown in as well.
And modern in this context means any known brand make amp, made in the last 25 years.
PS: How could I leave out Connect Amp?! That included as well.

No, it must be double blind. There are reams of scientific evidence that prove a single blind test is influenced by queues from the party who knows which is which. Which is why science insists on double blind studies.

But you already know this, because it has been discussed before. :rolleyes:

So when you bought your current gear did you ABX it?

If so how did you manage it?

To amplify on the above - examples of amps that may be compared and will meet the assertion in statement 1 are current budget models from Marantz, Rotel, Nad and the like, Quad 99/909 pre power, a Krell 400 wpc, all the way to the USD 100k priced Audio Note Ongaku. With cheaper Luxmans thrown in as well.
And modern in this context means any known brand make amp, made in the last 25 years.
PS: How could I leave out Connect Amp?! That included as well.

Hey Kumar if you can get an Ongaku and a Rotel in the same room I'm down for that comparison.. A-B.. ABX.. XYZ baby..

So when you bought your current gear did you ABX it?

If so how did you manage it?

No, I didn't, except for speakers, and that was a single blind so not really relevant. I also don't make any claims that my system, or any component therein, sounds any better than any other. I am confident that what I buy sounds good to me, and I do not need ABX testing to do that. In no way do I try to convince others of this, and aside from stating I have an Onkyo receiver that doesn't cause a delay from a Connect, I have never mentioned what equipment I own/owned, aside from Sonos. It simply isn't an issue for me, for I don't fancy bragging about gear, I find it rather gauche.

Now, if I were to come here and state the following:

I augmented my Sonos with a PS Audio PerfectWave Dac with the new Bridge.. I can now stream my Hi Rez files, and control everything with my Ipod Touch.. And Hi Rez just blows redbook away..



I buy lots of music off HD Tracks.. I use XLD to convert to 16/44 for my household Sonos system, I play back Hi Res in my main system with a PS Audio PWD MKII.. I can directly compare them.. The Hi Res sounds better.. hugely , jaw dropping better of course not, but better yes..



Then I most certainly would need to do an ABX test to lend any credence to my claims. If anything, I would certainly have to explain the reason why my assessment of Hi Res went from "blows redbook away" to "sounds better.. hugely , jaw dropping better of course not, but better yes" when switching to a unit that actually can play Hi Res? Could it be that intermodulation distortion? 😃

But don't you realize that when you state one digital cable sounds better than another, it is the equivalent of standing at the dock and saying to the sailors "Don't sail too far, you will fall off the edge!" Nobody with a scintilla of knowledge about engineering will take you seriously, and they don't have to "listen" (or sail too far) to know that you are speaking nonsense. And on top of that, when confronted with these facts, instead of admitting that your opinion makes no scientific sense, and that you may be experiencing a placebo effect or bias, you insult the objectivists ability to hear or the ability of their system to resolve differences.


OK, I'll bite on that...

You seem to be simultaneously:

(1) asserting a hypothesis that there are no circumstances in which a digital cable can affect the perceived sound quality of an audio system

(2) putting this on the same footing as the hypothesis (now known fact, of course) that the earth is not flat, and

(3) ridiculing anyone that disbelieves your hypothesis.

In order to prove that the earth is not flat, experiments were carried out or measurements were made to show that such a hypothesis was not consistent with observed facts. That's the established scientific method. However, before this, the prevailing scientific theory was that the earth was flat and those who believed otherwise were no doubt ridiculed. Scientific knowledge advances by continually seeking to disprove the current set of beliefs. (I know I'm stating the obvious here.)

I don't believe that it is possible to carry out a similar experiment to prove your hypothesis that there are no circumstances in which digital cables "make a difference" (to put it in shorthand). In order to do so you would have to show that for all combinations of cable, equipment and listener, there was no perceivable difference in sound. In principle this is impossible - it is after all trying to prove a negative. By contrast if anyone ever carried out an experiment with a single combination of cable, equipment and listener that demonstrated a repeatable difference under properly controlled conditions (e.g. DBT) your hypothesis would be falsified at a stroke. I'm not making any comment about how likely that is, I'm just pointing out that it's in principle possible to falsify your hypothesis but never to conclusively prove it.

As it happens, I do have a "scintilla of knowledge about engineering" and I can think of some reasons why digital cables may affect the sound quality of an audio system. Firstly there may be transmission errors in high-speed digital signals, and if there is no error detection and correction mechanism this could result in incorrect data being fed to a DAC. This can't be ruled out in principle over an S/PDIF connection, for one example. Secondly, a cable could inject noise via power or ground signals from a noisy device (e.g. computer) to a sensitive device such as a DAC. It's not unreasonable to suppose that this noise could be enough to cause LSB-level changes in the DAC output - for example, on a 16-bit DAC with a 2V range the LSB corresponds to 30 uV.

So just off the top of my head there are at least two not-totally-unreasonable methods by which digital cables could result in different output from an audio device, depending on the design of the equipment, the data the cable carries, the protocols used, etc. etc. Such differences could surely be measured in the lab with the right equipment, so it wouldn't depend on the human perception of sound.

Unless you believe that objectively measurable differences such as these could not possibly be audible by any human, I think this throws doubt on your hypothesis to the point that believing it becomes an article of faith rather than application of logic and science. Which is fine, provided you qualify it by saying it's your belief rather than making it out to be an absolute, unassailable truth that anyone would be crazy not to subscribe to.

My point is simply this: much as you insist on logic and science, it seems that you're not applying its principles as rigorously as the standards you set for others.

Each of us has our own belief system about what can or cannot "make a difference" in an audio system. Some people are biased towards the objective/doubting end, while others are at the subjective/accepting end. Speaking for myself, it's something that can change with time and experience (in either direction). My view is that while we might disagree we should at least be able to have a sensible discussion without ridicule and disrespect.

IanW, I have previously in this thread stated the following:

Yes, science gets stuff wrong. How do they prove it wrong? By carefully constructed experiments based on a new hypothesis that prove what was thought before to be incorrect. Carefully constructed experiments like a double blind study, none of which have ever proven the nonsense that digital cables, if operating correctly, make any difference in sound. If you conduct such an experiment and you actually prove there is a difference, then science will be proven wrong. Until then, you are simply reporting your bias . Good luck with that experiment..

I apologize for not stating the bolded more clearly. I don't consider a system plagued with transmission errors, or insufficiently shielded, to be "operating correctly". Furthermore, given these circumstances, the sound would suffer noticeable dropouts, not the "brighter, more spatial, wooly, warm, orange peel sound, apple juice fluidity" nonsense that audiophiles describe. It is these silly descriptions that I am speaking to, not easily detected sound deterioration due to actual errors or interference.

A bad cable is a bad cable, but the SPDIF standard was written to a generic video cable, you do not need a $1000 cable to cross the threshold of reliable performance, and once you achieve that, there is no way to improve on it.

As to this part of your post:

By contrast if anyone ever carried out an experiment with a single combination of cable, equipment and listener that demonstrated a repeatable difference under properly controlled conditions (e.g. DBT) your hypothesis would be falsified at a stroke. I'm not making any comment about how likely that is, I'm just pointing out that it's in principle possible to falsify your hypothesis but never to conclusively prove it.

That means to ball is forever in the audiophiles court. Which begs the question: Why the heck haven't they actually used series of DBTs to prove their expensive "digital" cables sound better?

I think we all know the answer to that.

In the first quote I had just gotten a PS Audio PWD with the Bridge.. It was so much better sounding than the Sonos alone.. the PSA Bridge also sounded better, and in my excitement I might have been more exuberant and credited the impressive increase in SQ to the Hi-Res files when it may have been as much or more the contribution of the Bridge.

In the second quote.. after having more time, I think a year or so, maybe you can clarify the timeline since you've done so much research. I came to get a better handle on what I was hearing. I also don't have a problem with being wrong my ego's good with it..

What I find fascinating though is how much you seem to care about what I think.. I mean it must have taken quite a while to dig through all the old forum posts to find just the right ones to wave in my face.. and a lack of grace .. I think that's really more your area of expertise.

In the first quote I had just gotten a PS Audio PWD with the Bridge.. It was so much better sounding than the Sonos alone.. the PSA Bridge also sounded better, and in my excitement I might have been more exuberant and credited the impressive increase in SQ to the Hi-Res files when it may have been as much or more the contribution of the Bridge.

In the second quote.. after having more time, I think a year or so, maybe you can clarify the timeline since you've done so much research. I came to get a better handle on what I was hearing. I also don't have a problem with being wrong my ego's good with it..

What I find fascinating though is how much you seem to care about what I think.. I mean it must have taken quite a while to dig through all the old forum posts to find just the right ones to wave in my face.. and a lack of grace .. I think that's really more your area of expertise.

Actually, I merely copied it from the last time I asked it. You refused to answer that time, and changed the subject to an attack on me. Thanks for taking the time to add an actual explanation in the middle of your normal pattern of posting.