OP,
This is not a “tube” problem. Not sure what it is… but this is never problem with high end audio equipment. So, either it is a PrimaLuna problem or a location problem. I would not abstract this to tubes or good quality components.
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?