P5 Voltage Out & THD Out Query


I recently installed a pre-owned P5 power plant into my system. I believe my P5 is a custom build as it is designed for UK/European voltage (230V) yet is fitted with US spec (NEMA) outlet sockets. Using the P5, my system sounds okay but a little grainier compared to the IsoTek Genesis One AC regenerator it replaced which is surprising considering the P5 has superior specification.

Delving into the status screen, the VOLTAGE OUT is always .1 volt lower than the VOLTAGE IN and never mirrors the value (230V in my instance) selected in SETUP. Is this normal?. Furthermore whilst the THD IN is a respectable 1.4% or 1.5%, the THD OUT is always 1.1% or 1.2% which is rather disappointing. Switching between MULTI and SINE waveform does not alter the THD OUT, nor does selecting 240V instead of 230V in SETUP. Dropping the PHASE a couple of notches sometimes lowers the THD OUT by .1 but that’s it. Does it seem like the unit is faulty?

The THD out is concerning. I would expect it to be 0.1%.


I forgot to mention when switching the mode from LOW DISTORTION to HIGH REGULATION, the unit switches off all 4 zones and the message ‘Voltage Output Too High’ comes up on screen. Any idea what’s going on?

Are you certain this unit is made to be used on your voltage?

Yes. The PS Audio sticker on the box bearing the unit’s serial number states voltage is 220 - 240, furthermore the voltage out parameters in SETUP is 220V - 240V.

I assume the VOLTAGE OUT on the status screen should reflect the voltage selected during SETUP? In which case, if you examine the photo I uploaded, the unit is only regulating voltage by .1. It might also explain why the unit shuts off all zones in HIGH REGULATION mode, stating ‘Voltage Output Too High’ as the actual output (248.6V) is higher than the 240V max limit in SETUP.

Unfortunately, I do not know. Hopefully, @jamesh will see this and has an idea or two.

Your inclination appears to be right. I don’t believe the P5 is working properly. The voltage should be regulating much closer to the intended output that you selected. Also Elk is right, the output THD should be much lower. Even with it powering your gear, it should be around .1 to .3% out. That unit should be looked at by the local distributor in your area.

Thank you.

My P5 was finally returned 3 months after sending it in for repair (repair was delayed for various reasons). It turns out the regeneration board was damaged so if anyone has the issues described above then it is likely the regen board which costs £750 ($1000) to replace plus labour.

Now that the P5 is outputting 230V at 0.1% THD as it ought, it sounds very impressive, particularly with source equipment. Unfortunately, in my system at least, it doesn’t provide a complete AC power solution because it doesn’t work it’s magic with my 34 watts per channel pure class A power amp. If I had to describe the difference in sound, with the class A amp plugged into the P5, it sounds like a big wall of music with transients sounding muddy, a little flat and occasionally harsh. With the class A amp plugged into the IsoTek Titan conditioner (but with transport, DAC and pre amp still plugged into the P5) there’s a proper three-dimensional soundstage and transients are clean, sweet and powerful.

Would a P12/P15/P20 remedy the issue or are regenerators simply not suited to class A power amps? I’m not thinking of upgrading, just curious.

I am having a very similar problem to what zenmonkey experienced; output voltage is always just a little below input and THD is not being reduced by much at all. The only difference is that my P5 is a standard US model (120 v.). It is several years old. Am I in line for a replacement regenerator board also? Or maybe it’s better to put the money toward a new P12.

Here is a link to One P12 for a pair of Emotiva XPA1 monoblocks
which in class A mode are 60watts read through as you scroll
down you will see pics of the power screen and further on
adding a Plinius SA 90

Not a bad showing for the “little” P12…
Wherever possible best save up for the P12…

I went fro P5 to P12 major improvement of P5…
then sold P12 to fund P15

Hope this helps.
Best wishes

:grimacing: Eeh, that’s not a good sign. That tells me the regen in there is no longer working properly. Voltage out should basically be a flat line and shouldn’t follow V in so closely. Also, THD out should be almost 0%. Again, not following what THD in shows.