Diagnostics for hum

Elizabeth for the win!

Brought it into the shop, $110.00 later it's singing again. Bad capacitors in the pre amp inputs.

Thanks for all the input. I guess it's off to the shop, or possibly time to buy a new amp.

Sounds like possibly a bad cap in common power supply. Not something playing around with lifting ground, etc. is going to solve.

Well, I am rather relieved to say that the cheater plug didn't work. Any other options before the trip to the shop? If I can even find one in OKC.

Anything motorized that has been added to the circuit can create problems. Ceiling fans, new gear, moving around interconnects, heaters and air conditioners, computers and so on.

I would first run an extension cord from another circuit to the gear and see if the problem is in the circuit. If the problem still exists, I would check my breaker panel and grounding rod connection to see if anything appears abnormal...ants or moisture, for example.

Cleaning all the connections and unplugging everything and reconnecting it is good audio housekeeping and worth a try.

Think real hard about any recent electronic purchases that you have added to your home that could possibly be on that circuit or polluting your juice. Battery chargers in the garage, for example. Anything with a transformer?

Sounds crazy to put a $.99 adapter on a $200.00 power cord, but I'll give it a shot. Do I need to screw the ground on the Cheater plug to the receptacle?