ASR: Impact of AC Distortion and Noise on Audio Equipment Fidelity

… guess who’s at it again? You guessed it toots … Amir … and he’s pickin’ a bit on PS Audio again … but no so directly … still, the guy’s gots ballz …

The video Amir posted just before the one above …

“Not everything that counts can be counted. Not everything that can be counted, counts.” Quote most often attributed to either Einstein or the sociologist William Bruce Cameron. In any case, it summarizes why objectivists and subjectivists cannot agree on the time of day. Notwithstanding psychoacoustical phenomena, I’ll never understand why anyone would put more significance on test equipment measurements than what is most pleasing to their ears. At least for me, the goal of this journey is to maximize the enjoyment my system brings me. My ears tell me if I’m on the right track.


I forced myself to watch both of these videos all the way through. And it’s obvious to me that what Amir has done is demonstrate the flaws or incompleteness of his “testing”.
No, all the consumers of these products like PSA regenerators are not hearing their sound quality improvements because we are all under some hypnotic spell, cast by Paul’s marketing genius.
As we might not yet have the measurement tools necessary, Amir should find someone with healthy hearing and add hearing tests to his toolbox.


An excellent comment. As an engineer by training, I couldn’t agree more with this comment. I wish those that get enjoyment through numbers and those that get enjoyment through their ears would perhaps just agree to disagree and stop trying to convince the other that they hold ultimate truth.


50 years ago we had a cheap and nasty communal stereo in the house I lived in. It would give very noticeable cracks when the refrigerator in the kitchen cut in and out. Most amplifiers in those days used simple unregulated power supplies, and this stimulated me to start designing and building regulated units. By 1975 these had become fairly sophisticated, and I decided to test one. I borrowed a big Variac from work to simulate brownouts, and connected my spin dryer to the same mains outlet to generate spikes when turned on and off. Neither brownout or spikes changed the DC level on the output by as much as a millivolt when viewed on an oscilloscope, and when the PSU was connected to an amplifier neither had any perceptible effect on music being played.

The conclusion I have drawn from this is that power regenerators should be unnecessary for equipment which uses a good regulated PSU. However, since there is no guarantee that this will always be the case, I cannot conclude that power regenerators are pointless. That original cheap stereo would certainly have benefited from one.


Ballz would be if Amir would undergo a blind listening test comparing gear he criticizes for measurements with gear that in his eyes measures great. I bet this would be quite embarrassing for him.

But what he has so far are not ballz but just a measurement console and too much time on his hands for nothing enlightening.


I can’t believe they tested the PS Audio P300. You should always test than at least also the current P10/12!

Pretty angry with them! My P10 has always worked fine (also with my amp.)

It would take effort to track down a P300, a product over twenty years old.

Amir has his approach and there are a good number his forum’s members who agree with him. There is nothing wrong with this, although most here would disagree with them.

A lot of his posts/videos come across to me as trolling.


It’s interesting reading this thread. What do you think most would disagree about?

Whatever the case, it seems Amir has a “thing” for PS Audio. He has repeated his “concerns” about PSA products in not just myriad videos, Amir’s forum is fulla these slams.
Paul: please create a video on PSA’s own channel countering Amir and diatribes.

There is no benefit in replying to ASR.

I am always tempted to close these threads instantly. We have beaten this dead horse numerous times and things go south quickly. Similarly, when the ASR folks show up at the Hoffman forum it gets particularly nasty.

Perhaps this thread will be different.


I don’t think any of us can determine if he has a “thing” for PS Audio, since none of us are him. I don’t believe this video was specifically about PS Audio Powerplants. After watching the video, it seems like he showed us objective measurements that demonstrate power regeneration not having an effect THD or SINAD. He also showed that regeneration did clean up the AC signal, so a Powerplant is doing what it’s advertised to do but since all devices convert AC to DC internally it did not have an effect on THD or SINAD. He did show a P300 but then found that his own device did an even better job regenerating AC so most of the tests you saw were with it. To further investigate this issue he then injected even more noise into AC signal (i think it was like 18% THD) and found that SINAD and THD were not affected. I don’t believe that test was flawed but it’s an interesting discussion if some believe it wasn’t.

I’m not sure where I would classify myself between a subjectivist or an objectivist and I’m really not sure why we need to form these groups in the first place. Even though I do own both a P20 and a P15, I with out a doubt believe that the audible difference I heard is influenced by bias an psychoacoustics. To determine if that’s true then I would have to remove those two factors from my listening test.

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:crazy_face: :laughing:


Absolutely correct!


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It would take effort to track down a P300, a product over twenty years old.

Got two, want one, maybe both? :crazy_face:

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Participation in this thread, or any related to ASR, is more of an act of self flagellation. :rofl: :upside_down_face:


If someone prods you with a red hot poker, you don’t ask them what temperature it is.

Measurements do have their place, but I rarely sit down for an evening and listen to sine waves.


Here we go with #QAmir again. Why is this guy still being talked about?

This would be a good topic of discussion:
What beverage pairing is best when listening to sine waves?