Is it time for a power conditioner?

I tried to isolate (heh) the problem to what was happening with my Lich having highpitched noise with audio input/through patches and it generally seems like it isn’t an easy problem to fix. Maybe if I have a 10 meter power cable for the module away from the 4ms case it is in…

I tried a passive isolator between the 4ms case and the computer soundcard and it was a bit better but it is a bit rediculous of a setup and mostly sounds like the noise is now a bit more muffled and warm…or just different - not really a solution.

i guess essentially once you have a desktop computer involved, it becomes blackmagic to catch the right star alignment for the noise to not get into your recording.

maybe this is all solved with a powerconditioner unit? Has anyone had similar stuff that they solved?
I tried a few cases, different sockets. Without a pc it is silent, unlike some of my other diy electronic modules.

Is the lich the only connection to your PC that you have in your setup?