P5 observation/issue after new firmware.


I recently purchased a dealer demo P5 and installed the new firmware. But when I use mw 6 my noise harvesters at the back of the P5 go crazy blinking really fast. Also my THD both in and out go up. If I use mw 4 or 5 it doesn’t happen, or if I adjust the phase from zero to 1,2,3,4 etc it doesn’t happen. Any ideas why this is happening?




@sircharles where are you located geographically? Some locations have issues with power supply “noise” generated by the addition of the 3rd harmonic waveform (which is what the multiwave does). Noise harvesters detect the out of phase 3rd harmonic as noise, and buzz accordingly. Keep multiwave at 6 but adjust the phase such that you get the lowest possible THD-out reading. This should then work perfectly.


Thank you stereophilus…I live in the East Coast (MA)…,and I typically get a THD reading between 3.5 to 4.2 coming in. Also I experience voltage swings of anywhere from 110-122V. I have adjusted the phase tune to 2 and kept the MW at 6. This has produced a THD output of 0.2% to 0.3% consistently. I really like the sound I am getting and the noise harvesters are not blinking frantically as before, but they are still more active than when MW 5 or 4 is selected. I am fine with that though…


Are you plugging the noise harvesters into the back of the PowerPlant itself?

If so you will not physically harm anything, but the NHs and PowerPlants do not play well together in this fashion. Best results are obtained by plugging the NHs into the wall.


@sircharles Glad I could help. Paul McGowan has previously mentioned some East Coast locations have had this problem with multiwave function. It is to do with the power supply to your house. The phase shift option on the P5/P10 multiwave was designed to reduce the issues related to this. It isn’t a perfect solution, so the more multiwave you use (6 being maximum) the more potential problems arise.

Also, as Elk suggests, NHs work best on mains sockets, rather than attached to the Powerplant, but that is a minor issue.

The only other option to improve your power output is to get an oscilloscope and do some FFT analyses.

stereophilus said: . . . but that is a minor issue.

Yes, I should have made this clear.


Indeed, NHs work best on the input mains not on the output of a Power Plant. I would remove them.


So I removed the noise harvesters from the back of the P5 and plugged them into all the outlets (4 in total)

that are in the same 20amp line and they still blink like crazy. A newer observation now is when using MW 6 and phase tune 1,2,3,4 etc the NH go quiet and go crazy randomly for a period of 2-3minutes then settle down to a steady blink (every 2-3 seconds) then randomly go crazy again. I should mention that the THD in and out remain constant (3.5 In and 0.2 out). The THD only goes up when I use MW 6 and phase tune of zero. I am however really liking the P5 and the positive effect it has brought to my system. Just wondering what’s going on with the random behavior it’s imposing on the electrical line as shown by the craziness of the NH.

sircharles said: . . . plugged them into all the outlets (4 in total)
that are in the same 20amp line and they still blink like crazy.

This means they are doing their job. :) And if the system sounds good, the PowerPlant is doing its job, too.

The PowerPlants can put noise back on to the line unfortunately, but I expect this to be constant unless the incoming power varies.

If you turn off and unplug the PowerPlant and just watch the NHs, what do they do? My guess is your incoming power is a bit noisy and varies.


When I unplug the Power-Plant the noise harvesters don’t blink at all…(maybe once every hour they might blink)… They also stay quiet if I revert back to MW4. They only started working or blinking like crazy when I went to MW6. They also seldom blinked when I used the PPP.


Very interesting. I did not expect the PP to put that much noise back on the line and that it would be so variable.