Very high THD, low voltage out with P5


#1

I’ve been looking at the graphs for the performance of my P5. The following has been consistent over the last three months (that’s as far back as I looked). Average THD output (red line on the graph) ranges between 6.0 and 7.0 while the incoming THD is consistently around 1.5.

After writing the above, I decided to look back another couple of months. Something seems to have happened on May 25. Prior to then I was cruising along with nice low THD and output voltage just over 120. See the screen shots below. I believe the P5 did restart itself once but I don’t remember the date (not very recently, could have been May). I haven’t changed any equipment since last fall; I have a DS Senior, a DMP, a turntable, and a BHK 250 plugged into the P5, which I don’t think would overstress it.

Do these data indicate a damaged unit, or is it something I can adjust? Should I stop using the P5?P5-THD.pngP5-voltage.png

Thanks for any suggestions!


#2

I suspect your regenerator may have died. This does not look good.


#3

It’s a common fault with P5 (I’ve had three P5 go down with this failure mode). It needs to go back to the dealer (or PS Audio) to have the regenerator board replaced.


#4

Thank you both; I will contact customer service on Monday.

This also shows the usefulness of the graphs, which I had not looked at before. The strange thing is that the system continues to sound so good. An audio buddy was here last week and raved about the sound; I wonder how different it would have been with much lower THD!


#5

Check the P5’s front panel to make sure. But, if it too shows higher levels of output distortion than input, then Elk’s right. You’ll need to send it in for repair. It won’t damage anything while in use but it won’t sound right either.


#6

Thank you, Paul. Good to know it won’t hurt anything.


#7

The historical power record was recently of interest to me. One of my PowerPlants was clicking between regenerated power and straight from the wall, and one of my remote controlled ceiling fans was randomly beeping and turning on/off.

Checking the graphs later, I saw the incoming voltage was 112V with 10% THD. Interesting stuff.