A portable cd player plugged into the amp resulted in no noise, so I guess
the amp is fine. Once I get time this weekend, I will play with the head
unit ground. Do I have to ground the HU at the same point as the amp, or
will a good ground up front suffice?

couple random questions:
Do the power lines to the HU sometimes give noise like a bad ground would?
Do power filters, ground loop isolators, noise supressors, etc work? How?
(I plan on fixing the real problem before trying one of these band-aids, but
am just curious)

Thanks for all the replies!

Ben

"Mark Zarella" wrote in message
...
No, I did not try messing with the head unit ground, thank you for
suggesting it. What about the head unit ground would make the noise
thru
RCA's but not hi-level inputs, even when the engine is off? A ground
loop?
As I said in my first post, any info is appreciated.

This group is full of DIY'ers. If you are that experienced, please use
it
to help us, not disrespect our newbie questions (which btw, I have seen
far
more basic and obvious questions answered in this group).

I gave you my best recommendation. You rejected it. Instead, I'll
suggest
that you make sure that the problem is with the amplifier first by trying
a
different low-level source. A portable cd or mp3 player perhaps?

Although the evidence so far points to the amp, you need to explore all
avenues first as most repair shops charge you just to look at an amp.