jg2077 OP41 posts
12-11-2019 7:52pm
All was unplugged from the back of the pre, I still have "hum".
I ran a ground wire from the pre power cord (plugged into the back of the power distributor) to the ground of wall outlet the power distributor is plugged into; the hum remains...??
Many thanks for all advice given,
That won’t work. Adding a parallel ground path will solve nothing.
Use a ground cheater on the ARC preamp power cord plug. (Nothing connected to the inputs of the preamp. Again just the preamp and the 2 amps. Nothing else)
You need to lift, float, the equipment ground from the chassis of the ARC preamp. That will break the ground loop circuit.
By chance do the Krell amps have a ground lift switch on the rear panel? If so the switch will lift the signal ground of the amps from the safety equipment grounded chassis.
Just a note. At this point I am hoping the problem is the equipment ground of the 15 amp convenience outlet circuit. The ground cheater on the ARC preamp power cord will tell us that for sure if it breaks the ground loop and hum.