Sub plate amp hum/crackle

[GhettoSQ]

Sorry for posting this again months later. I posted about this on the subs forum but thought I might have better luck here.

I have the MCM $50 plate amp, it introduces hum into my system whether I use the preamp inputs or speaker-level inputs. System is otherwise dead quiet. Groud loop isolator fixed the problem and made the system sound like crap (my wife noticed it immediately, I'm not hallucinating). Back to square one. I tried all combos with other plugs and outlets to no avail. It does go away if I unplug connections to the amp or if I unplug both amp and plate amp, then plug the amp back in.

anyone have any ideas?

[GhettoSQ]

BUMP

I realize my question above is a bit silly, since the GLI fixed the problem there must be a ground loop. I just hope there's another way to solve it since the GLI hurt the sound quality.

Also, today it's just kind of a hiss -- barely noticeable but more than it was without the sub.

[richie00boy]

Are all parts of the system plugged into the same mains socket?

[GhettoSQ]

Yeah, they are all on a power strip into one socket. I tried just the two amps (main and sub) on the two outlets of the socket too. I changed to a slighty heavier-duty power strip too, to no avail.