Any power conditioner is an additional resistance for the mains voltage to the transformer or SPS of any audio gear.
So if you can really hear anything, it will be reduced power of your amp or whatever you use it for.
I use quite cheap power distributors with some overvoltage protection capability in my systems. Maybe it helps if something bad happens on the AC line.
My main system has it's own power cable going to it's fuse in the house installation. That prevents spikes from motors, refridegerators and the like to dirctly enter the audio. It cured some glitch in the TV when the fridge switched on.
I use a special power cable to the AVR. This has some very physical reason and gives me peace of mind. It draws the highest current in the system and thus will have the strongest magnetic field. I use a shielded LAP Oelflex cable with low price "made in Germany" industry quality plugs. The shield is only connected to the wall side. Because I can't run all wires separately behind the AVR, this may prevent the AC field of the AVR power entering other wires running in close proximity. Is is audible? Not for me. Anyway, it costs not more than a "regular" AC power cable, maybe 1€ more per meter. The complete 1m cable comes at the cost of about 9€ and less than 15 minutes of my time. I promise it will sound just as good as any 20.000$ high end power cable.
If not I will buy you a beer to wash your ears.
Hey, it is hand made in Germany, you can't beat that, not even with stink'n Amazon China cable!
This is how it looks:
View attachment 390903
