Have you tried a Ferrite Ring Core RFI EMI Noise Suppressor Cable Clip, you can find them on Amazon and eBay? I had a serious issue with rfi in my system, I could hear the local am radio station broadcasts. I bought a package which included several different sizes that I was able to put on all cables attached to my amp and throughout my system. It offered me quite a bit of relief. I hope you figure out the problem, I know what it frustrating experience this can be.
Never heard an amp do this before, ideas?
I have a primaluna 100 unplugged from any inputs. It has this awful high pitched sound coming from the speakers when it's turned on. It happens on both channels, and through headphones.
I have turned off all electricity in the apartment, turned all breakers off except the one it's on, moved the amp around the apartment, tried a humx, and different power cables. I even replaced the unit with another primaluna and they both do it.
I'm running out of ideas, anyone ever seen this before?