Power conditoner..

@fertguy the PP is programmable to put out whatever voltage you want.  Like I said, the voltage doesn't matter.  the quality of the sine wave is what does.  

If you are getting no improvement, the power supply in your amp (and other equipment) must be very good and manages the noise in the wall power.

What amp do you have?

Jerry

@fertguy

Return it to PS Audio after discussing with them first. I know that power amps can draw a lot of current and that you must be careful to make sure that your power device is up to the task of delivering lots of current during musical peaks.

If the lights are brighter enough to notice, your mains voltage must be pretty low. Have you listened to stereo with generator on?

Carrlsbad2

That is a good Approximation, BUT

An Amp can ONLY produce  a relative output within and given operating range. If you have say low power you can not get something from nothing, that isn't there to begin with and you will have a comparatively weaker output. If your Bias voltage is off or your output supply voltage is Low/High, your output will change along similar lines. The circuit can TRY to compensate but there is no circuit that can demand an output. Even a constant current amp has it's limitations.
On the other hand your statement about PP is right on and that is a great place to lock in some stability and consistency.

PS Audio PowerPlant, like everything else audio, is a YMMV thing.

"the PP is programmable to put out whatever voltage you want. "

The OP's model does not have that feature.