Make sure the unit is grounded some how. Lifting the ground on the plug can be very dangerous since the chassis becomes hot if the unit should fail, leading to potential nasties. I believe the proper way is to use a balanced transformer to stop ground loops. Another neat way is to use input transformers on the RCA jacks, a la Rowland. I won't deny the potential benefit of using cheater plugs since I have but don't now since my health is not worth any incremental benefit (ALL sonic benefits being incremental when I speak of my health). There was a healthy discussion on this on Audio Asylum and that's where I decided to prevent future shock, as it were, and plug 'em all in as should be done...
Lifted grounds- No more FM distortion on Tuner
I just realized that my FM reception is 100% perfect now. I recently got a pair of Rogue M120 Magnum Monoblocs and lifted their grounds. The Tuner and the pre is grounded. Prior to this upgrade the Tuner would have lousy FM reception and would get better in the late evening. Before the upgrade my integraded and all other components were grounded. Was I getting a ground loop which was affecting my Tuner reception? Why did this happen? What causes the ground loop?