Not to go on and on about my alternator whine (I've started like 3 threads on it) but could it be a bad amp?

I have two amps (one is a cheap 4 channel Rockford 35watt amp and the other is the amp in my Infinity Basslink). Both are grounded at the same point: to a bold under the seat. I even tried the top of one of the rear strut towers. Now it is hooked up all the way to the battery's neg. power post. The whine is always the same.

I had the empeg grounded via the factory wiring harness's ground and now it also has a direct line to the negative post of the battery. I even tried one of those capacitors that you connect to a head unit, but I tried it on both the accessory power and on the main power lines.... no change.

Could it be that I have a bad amp? I'm thinking of changing to a 5 channel amp so that I have just one power and one ground as far as amps are concerned... just to elinimate one factor.

Back to this thread: Did any of Tony's links help? It certainly sounds like an install issue and not something Subaru related.