Audio Systems: car audio, infinity kappa speakers, pioneer head unit

Question
Installed pioneer head unit with a panasonic amp..infinity kappa speakers...this is a four channel amp..have a noise when  car is switched to acc and is worse when started revs of car can be heard..on acc I can drown the bad noise out but not when car is running...all wirring checked and double checked..so I ran the head unit off a seperate battery ..noise is gone..so head unit power is the problem I think..how can I solve this problem

Answer
If you hadn't said the brand of head unit, I would have guessed Pioneer. They are notorious for the noise filter circuit to go bad.

I have found the only cure is an inductive type noise filter (this is just a band-aid for the real problem) or repalce the HU with a different brand.