ground loop HUM please help


I have pre tube amp ( supratek -Cortese) running a pair of Krell mono block FPB-250 . I have a loud hum when the preamp and the amp turn on . The hum goes away only if I used cheater plug for both preamp AND amp but I'm afraid it will damage the amp . Is there any other way to result the problem ?. thank you for any input
winsound
The best formula for avoiding ground loop hum is to only ground one component, for example maybe the preamp. Use cheater plugs on the rest of the components, they are still grounded via the interconnects because they are connected to the preamp that is properly grounded.
Granite Audio makes a device called the Ground Zero that should solve the problem. It's a bit pricey but comes with a 30 day trial.
Do you have cable tv/music as one of your inputs? If so try disconnecting the cable input and see what happens.