PS Audio P12 Review Part 2: Power Testing

[phoenixdogfan]

Ol' grandpa Paul is peddling snake oil?? Say it ain't so!

I watched a few of his videos and cringed when he started talking about matching cables to his products.

What's so appalling is that he's a fine engineer, so he has to know that the stuff he's putting out there is bullshit and his products are pure snake oil.

I would personally have no objection if he just put out performant amps/dacs/preamps with a fancy front plates of brushed aircraft aluminum that was overpriced in the multi kilobuck range. Everyone should know by now that stuff is overpriced and they're just paying for the fancy front plate and the brand name.

But stuff like power plants and $1k power cords. That's beyond the pale, and he's trading off the goodwill he built as one of the founding manufacturers of the high end to pimp that crap. And that kindly grandfatherly persona he wraps around these swindles is just so over the top. He has to know how it looks to people in the know in the industry and apparently doesn't give a shite.

 

[LEFASR160]

I am silent because your answer was in the review and repeated by multiple members. Once more, I don't know how this meter measures impedance or how accurate it is. I just found it curious that it showed much worse impedance with P12.

As to comparing my measurements to theirs, none of us know how PS Audio measured impedance. Unlike me, they are not even telling you the instrumentation they used so we could assess its accuracy. Their stated number could just be computed (theory), at some frequency, and at a point internal to the box. Headphone amp manufacturers for example measure output impedance right at the connection to the headphone jack, not at the end of headphone cable.

Given the above, you can't compare one methodology of measuring impedance against the other.

Also, the big deal in this review was not the impedance measurements but rather, how power dropped in a real amplifier with P12. The claim that the P12 somehow delivers more power kept repeating in the other review thread. So I put it to test and the outcome was the other way around with P12 reducing power by almost 10% -- both peak and continuous. If you were going to ask PS Audio something, this would have been the question to ask. Remember, you listen to audio devices, not the impedance of AC power.

So far Paul at PS Audio has just posted a flippant answer:

View attachment 190660

Notice how continues to use words as opposed to hard data to counter mine. Focus on this. Ask them to repeat my measurements and show different results. If they can't or won't, then the conclusions of my review stand.

Thank you, Amir, for your answer (finally). I will definitely follow up with an email to PS Audio again asking what you just said. Standby....

 

[LEFASR160]

I am silent because your answer was in the review and repeated by multiple members. Once more, I don't know how this meter measures impedance or how accurate it is. I just found it curious that it showed much worse impedance with P12.

As to comparing my measurements to theirs, none of us know how PS Audio measured impedance. Unlike me, they are not even telling you the instrumentation they used so we could assess its accuracy. Their stated number could just be computed (theory), at some frequency, and at a point internal to the box. Headphone amp manufacturers for example measure output impedance right at the connection to the headphone jack, not at the end of headphone cable.

Given the above, you can't compare one methodology of measuring impedance against the other.

Also, the big deal in this review was not the impedance measurements but rather, how power dropped in a real amplifier with P12. The claim that the P12 somehow delivers more power kept repeating in the other review thread. So I put it to test and the outcome was the other way around with P12 reducing power by almost 10% -- both peak and continuous. If you were going to ask PS Audio something, this would have been the question to ask. Remember, you listen to audio devices, not the impedance of AC power.

So far Paul at PS Audio has just posted a flippant answer:

View attachment 190660

Notice how continues to use words as opposed to hard data to counter mine. Focus on this. Ask them to repeat my measurements and show different results. If they can't or won't, then the conclusions of my review stand.

@amirm OK Amir, will do.

I just sent another email to PS Audio:

Dear PS Audio:

I have a follow up question:

Amir H Majidimehr, founder of Audio Science Review said: "The claim that the P12 somehow delivers more power kept repeating in the other review thread. So I put it to test and the outcome was the other way around with P12 reducing power by almost 10% -- both peak and continuous.”

So how does PS Audio explain this result ?

Best Regards,

 

[MaxBuck]

I'm proposing this pink buddy as a symbol for snake oil products.

View attachment 190508

I think that's actually a multicolored, anthropomorphized sperm.

Still appropriate IMO.

 

[audio_tony]

With direct connection to the mains, the Outlaw 2220 produced:
371.3w / 561.2w (max power / peak power)

Via the P12:
343.3w / 518.6w (max power / peak power)

Assuming that the (input) line voltage was consistent across tests, the power output of the Outlaw should have remained constant.

It would have been useful if @amirm had measured the (raw) line voltage in both cases, as assuming the P12 does have high output impedance, the voltage would have dropped as power draw was increased.

It would also be relatively trivial to measure the voltage drop across the P12 as current draw was increased. Measure a large voltage drop, and that indicates that the P12 cannot maintain output voltage, either due to high output impedance, or poor regulation.

 

[LEFASR160]

I am silent because your answer was in the review and repeated by multiple members. Once more, I don't know how this meter measures impedance or how accurate it is. I just found it curious that it showed much worse impedance with P12.

As to comparing my measurements to theirs, none of us know how PS Audio measured impedance. Unlike me, they are not even telling you the instrumentation they used so we could assess its accuracy. Their stated number could just be computed (theory), at some frequency, and at a point internal to the box. Headphone amp manufacturers for example measure output impedance right at the connection to the headphone jack, not at the end of headphone cable.

Given the above, you can't compare one methodology of measuring impedance against the other.

Also, the big deal in this review was not the impedance measurements but rather, how power dropped in a real amplifier with P12. The claim that the P12 somehow delivers more power kept repeating in the other review thread. So I put it to test and the outcome was the other way around with P12 reducing power by almost 10% -- both peak and continuous. If you were going to ask PS Audio something, this would have been the question to ask. Remember, you listen to audio devices, not the impedance of AC power.

So far Paul at PS Audio has just posted a flippant answer:

View attachment 190660

Notice how continues to use words as opposed to hard data to counter mine. Focus on this. Ask them to repeat my measurements and show different results. If they can't or won't, then the conclusions of my review stand.

@amirm Amir: What is the date of this flippant answer from McGowan ????

 

[Pogre]

And that kindly grandfatherly persona he wraps around these swindles is just so over the top. He has to know how it looks to people in the know in the industry and apparently doesn't give a shite.

That kindly grandfatherly persona turns my stomach. It only makes it worse because, damnit, he is a likeable guy. I can't see him that way tho because I know he's fulla shite.

I've seen how he brushes people off who question his claims, and it's pretty telling that refuses to participate in any controlled listening tests, provide any actual data or have an open debate. He had a short back and forth with Gene DellaSala about his his partnership with Audioquest and gave a bunch of slippery nebulous replies. PSAudio and Audioquest... now THAT is a match made in science fiction, lol. And not good science fiction either!

Yeah, I'm not a big fan either.

 

[restorer-john]

With direct connection to the mains, the Outlaw 2220 produced:
371.3w / 561.2w (max power / peak power)

Via the P12:
343.3w / 518.6w (max power / peak power)

Assuming that the (input) line voltage was consistent across tests, the power output of the Outlaw should have remained constant.

It would have been useful if @amirm had measured the (raw) line voltage in both cases, as assuming the P12 does have high output impedance, the voltage would have dropped as power draw was increased.

It would also be relatively trivial to measure the voltage drop across the P12 as current draw was increased. Measure a large voltage drop, and that indicates that the P12 cannot maintain output voltage, either due to high output impedance, or poor regulation.

The P12 regulates the output voltage to within 0.5%. If the mains voltage was high, its output voltage would have regulated lower, accounting for the difference in measured output power on the Outlaw amp.

The mains impedance Amir measured with his Hot/Active line at 3R is clearly erroneous.

 

[LEFASR160]

@Pogre @phoenixdogfan Paul McGowan isn't making many friends on this site !!! hahaha

 

[LEFASR160]

The mains impedance Amir measured with his Hot/Active line at 3R is clearly erroneous.

@restorer-john @amirm Are you sure ? I thought it probably was erroneous or else the unit was broken...it was way too far off the spec to be real. That's why I asked. I'm not a EE person and don't claim to know much about electronics but I'm a good learner and have an advanced scientific and educational background...and when I smell something wrong, I speak up !!!! Can you back that up with evidence/logic/proof ? Amir says his measurement of the impedance is not important. And I accept that, but I'd like an exact output impedance measured. And if not, and if the number he gave is not important, then it shouldn't be in the review.

 

[amirm]

It would have been useful if @amirm had measured the (raw) line voltage in both cases, as assuming the P12 does have high output impedance, the voltage would have dropped as power draw was increased.

Unfortunately I can't perform dual measurements like this. AP is tied up performing the amplifier measurement and can't be used to simultaneously measure the AC. Standard tools I have for voltage measurements (e.g. meters) are too slow to track the activities of AP trying to determine power.

I tried looking at the P12 meters but they are ridiculously slow and as such, useless for this purpose.

At the end of the day, it doesn't matter "why" but the results we achieved.

 

[audio_tony]

The P12 regulates the output voltage to within 0.5%. If the mains voltage was high, it's output voltage would have regulated lower, accounting for the difference in measured output power on the Outlaw amp.

The mains impedance Amir measured with his Hot/Active line at 3R is clearly erroneous.

So in that case, it would have been instructive had Amir measured the (AC line) input voltage to the Outlaw in both test cases.

Perhaps even used his lab AC supply set to the same voltage as the P12 to provide a comparison.

Either way, the test is not valid without knowing what the AC input voltage to the Outlaw amplifier was in both test cases because as you say, the P12 regulates the output voltage (something I had forgotten about when writing my initial post).

 

[audio_tony]

Unfortunately I can't perform dual measurements like this. AP is tied up performing the amplifier measurement and can't be used to simultaneously measure the AC. Standard tools I have for voltage measurements (e.g. meters) are too slow to track the activities of AP trying to determine power.

I tried looking at the P12 meters but they are ridiculously slow and as such, useless for this purpose.

At the end of the day, it doesn't matter "why" but the results we achieved.

A simple measurement with a trueRMS AC voltmeter would have sufficed! You must have a couple of those available to you?

 

[Pogre]

@Pogre @phoenixdogfan Paul McGowan isn't making many friends on this site !!! hahaha

I watched a handful of his videos and he really does come across as everyone's wise ol' lovable grandpa, dispensing sage advice from a place of knowledge and he's just straight up fulla shite. Peddling snake oil for ridiculous prices on devices that don't even need to exist for this hobby. That kinda thing just pisses me off. Guys like him promote using flawed reasoning, and there's enough of that to go around as it is.

 

[amirm]

Perhaps even used his lab AC supply set to the same voltage as the P12 to provide a comparison.

My lab AC generator is limited to 300 VA so doesn't have the capacity to run this test.

 

[amirm]

@amirm Amir: What is the date of this flippant answer from McGowan ????

Earlier today. See: https://forum.psaudio.com/t/bad-review-about-ps-p12/27836/99

 

[LEFASR160]

The P12 regulates the output voltage to within 0.5%. If the mains voltage was high, its output voltage would have regulated lower, accounting for the difference in measured output power on the Outlaw amp.

The mains impedance Amir measured with his Hot/Active line at 3R is clearly erroneous.

@restorer-john @amirm So are you saying that the 10% drop in power of the amp could be due to a voltage regulation DOWN by the P12 in the face of a high voltage MAINS ? If that is the case, then what's the point of the test ?

 

[amirm]

A simple measurement with a trueRMS AC voltmeter would have sufficed! You must have a couple of those available to you?

I have 20 of them but they won't work. AP uses an iterative process to find the wattage that produces 1% THD. For this, you give it a start and ending value for input voltage to the amp. AP then iteratively goes up and down in voltage and hence wattage until it hits 1%. Once there, it stops and reports the power. During that period, power will wildly change from one value to the other (including clipping the amp), until it gets the right value and instantly stops. A volt meter as such would just show jumping values unless it never changes.

 

[amirm]

@restorer-john @amirm So are you saying that the 10% drop in power of the amp could be due to a voltage regulation DOWN by the P12 in the face of a high voltage MAINS ? If that is the case, then what's the point of the test ?

I am not. It could be current limiting as well. It could also fall out of regulation momentarily. Who knows.

My job is to black box test the unit, not analyze what it is doing. That is for PS Audio to do. I measured the amplifier with raw AC and with P12. The latter produced less power. That is the end of the story. Everything else is guessing but not important in the context of someone buying this unit for this purpose.

 

[restorer-john]

@restorer-john @amirm So are you saying that the 10% drop in power of the amp could be due to a voltage regulation DOWN by the P12 in the face of a high voltage MAINS ?

Yes. It could be partially due to regulation and partially due to output impedance losses in the P12. We don't know.