I think Dave meant different grounding points. And yes, you will have a high probability of introducing noise that way (or so I've heard). It happened to me too, prior to getting a ground block. Move all your equipment gorund to one spot to try and eliminate ground loop.
Originally posted by joshpoints
The noise happens when the rca's are disconnected from the headunit, but when I disconnect the rca's from the amp the noise stops. Here's what I find strange. None of this happened with my other amps. I think they may have had better noise rejection. I'm going to try hooking one of my other amps back up and I'll see if it still makes noise. The amps case is on carpeting. Have any of you used isolators with success? I tried a new grounding place and I still have the noise. Will cleaning the ground surface help, or is this problem unavoidable when the HU and the amp are grounded at different potentials? Also what do you mean when you say grounded at different potentials?
Sony C90, 210 EQ
Seas 27TDF/C, RE XXX 6.5, custom xo (dyn 240GT sitting idle)
RF 60.2 amp
Soundstream picasso 1400.1D
Bass drive-by's are uncool.