Ground loop hum is much more easily solved by disconnecting the ground sheild of any cable TV line, and by having all your components plugged into the same outlet (thus on the same ground). Lifting the ground on all your hardware is a recipe for disaster.
Weird Thing after I lift my ground.
I've finished lifting grounds on my system by buying 3 cheater plugs for my A/V pream, CD-Transport, and DAC. During the process of lifting grounds I switched everything off and unplugged everything from outlet. After that I plugged everything in the same place except those three units that I plugged them through cheater plugs. Now I see the weird thing. Whenever I stop CD-Transport or switch it into the standby mode, the "signal lock" LED of my DAC always blinking like it's trying to lock the signal. If anyone has experience this kind of situation or can explain this situation, I'm really appreciate.