Typically when a Power Plant fails the outgoing THD is as high as the incoming or higher. It is also common for a failed unit to make a lot of clicking noises.
While 0% outgoing THD surprises me, your incoming THD is low enough the outgoing will be very low. Perhaps the unit is rounding down in this instance.
Edit: I note you are in Japan. I do not know how a US Power Plant behaves with your lower voltage and higher cycles, 100V/60Hertz.
Thank you for your comment!
My incoming thd is 1.8-2.0% so it seems quite good already, but other 2 Japanese version 100V PPP output thd is usually 04.-0.5%… only this unit out 0.0-0.1%, so I am wondering.
I’ll be very happy if this particular unit is a good one though.
Thank you for chiming in!
Yes I’m in Japan. I am using 2 JP 100V PPP already and the other day I bought US version to feed 120V gears in my private studio.
Drawing 200V from breaker to the wall outlet and reduce it to 120V using step-down transformer, then it goes into PPP.
So technically it should work like it’s in US.
There’s one thing I noticed that it boost up to 115-116V when connected to JP outlet which feeds 105-108V, on the other hand it reduces incoming 122-123V from step-down transformer to 115-118V, in both situation voltage adjustment is in highest setting.
Is this behavior normal?
Also, only when it is connected to step-down transformer it makes a little hum noise from its body, I guess it’s its transformer inside. it annoys me in the quiet situation.
Almost no sound when it’s connected to JP 100V outlet.
At least no problem in the sound compare to another PPP, so it is working fine I guess.
By the way I really love this product… I was blown away when I installed this and asking myself why I didn’t buy it earlier.
wondering how good P15 or P20 are.
I would plug this PPP into the output of the PPP that reads 0%.
Then measure the incoming distortion level on this known good unit.
If you read under 1% distortion incoming, the output of the unit in question is probably good.
Much more than 1% and it is not regenerating properly.
I tried to connect US PPP to another unit but it keeps making clicking noise and both unit’s in and out THD rises like 3-4%.
Both unit behave the same when those are connected other way round, so I guess it is because of AC FAN inside…? I guess I read some article says that you can not use gear using AC like electric motor or something in PPP or any regenerator.
BUT I tried another thing, connect tube guitar amp to this US PPP then it shows 0.5-0.7% THD when it is turned on and go back to 0% after turned off.
So I guess it works properly and the most important thing is, it sounds significantly better than another unit.
The cause of difference could be that one is connected to wall outlet directly(not audio dedicated outlet), and the other is connected to 200V to 100V step-down transformer from dedicated 200V outlet though.
Still I have a lot of question to ask to PS Audio people, I am happy it sounds great.