Amir and Blind Testing

emailists,

It appears you have not gone through that second review.

Amirm DID originally do tests on the other Zone A outputs, but only used the last outputs for the amp on the very rational inference that since they were labelled "high current" those would be best for powerful amplifiers.   The owners manual tells the user the voltage output is the SAME ACROSS ALL ZONES so there is nothing to suggest any problem with using the zone D outputs.

It's entirely PS Audio's fault for this lack of information for the user.

Paul McGowan didn't help with information by claiming the D zone didn't regenerate power, so Amirm shouldn't have used it.  Amirm's own measurements showed Paul was wrong, that it DID regenerate power.  Paul later admitted to the mistake.

So the source of accurate information here has been Amirm's measurements, not the user manual nor the company spokesperson!

No user, or prospective customer, would likely know any of this without Amirm having measured the unit. 

Further, as I understand it, PS Audio never reached out to Amirm to try to "correct" anything in the review.  Rather, Amirm was alerted to some dialogue in the PS Audio forum criticizing his review.  So he took it upon himself to take another look addressing the criticisms and the additional claims made by McGowan in the thread.   THAT is actually being a conscientious reviewer!   But of course you apparently don't want to give him any credit possible.

Plus Amirm showed that even the other zones regenerating power did nothing to help with amplifier power/dynamics or anything that would support the company's claims for how it will elevate the sound quality of your system.

For those who are interested, Paul McGowan has put together a video on the PS Audio forum that explains what the P12 regenerator does and how to measure it correctly.

It was completely predictable that PS Audio's damage control video would miss the point.

These companies always make claims that attaching your gear to their product "dramatically improves the SOUND of X, Y and Z in your system."

But they never DEMONSTRATE any measurable - or audible - change in the SIGNAL COMING OUT OF GEAR ATTACHED TO THEIR PRODUCT.

It doesn't matter much if you are "correcting" for problems that are either generally corrected for in the design of lots of gear (e.g. amps) or that are not audible in the first place.

THAT was the point of Amirm's review.  Amirm showed that, yes, the power plant DID regenerate and regulate the power IF YOU JUST MEASURE at the power plant.  The question was "But what BENEFIT are we likely to see when you attach an amp?"    That's what Amirm did, showing there was essentially no benefit likely to make any audible difference.

This is, of course, precisely the issue the new PS Audio video avoided.   They just did the usual "Look how our device alters the power" and then IMPLIED that this has the audible benefits they claim.  It's that last bit they are missing.

Prof, with all due respect, Amir's approach still assumes that he is measuring everything that matters in terms of ultimate sound quality. I think that is unlikely to be a valid assumption. If Amir's assumption of perfect measurements is invalid, then the importance of human listening cannot be excluded from any evaluation of a product designed to improve the sound quality of reproduced music. 

Amir talks up the value of unbiased listening tests, but then admits that he is clearly biased and unwilling to go to the trouble of setting up any unbiased listening tests himself. That is the bit that is missing from most of Amir's reviews, including his P12 review. 

Amir's approach still assumes that he is measuring everything that matters in terms of ultimate sound quality

I don't see that, he's measuring the DUT and seeing if it does what the manufacturers claim it does. 

Amir talks up the value of unbiased listening tests, but then admits that he is clearly biased and unwilling to go to the trouble of setting up any unbiased listening tests himself.

Why would he set up BDX testing of a component that doesn't do what's claimed? It isn't his place to conduct a DBX but those who claim the component does things the measurements clearly show isn't possible.