Ran dedicated wiring for the second amp, everything works fine now. They only thing is a popping sound when the head unit turns on\off and changing songs on the ipod. I tried a different RCA cable, verified all the grounds, changed the output on the head unit, verified the grounds on the amp, couldn't get rid of it. Since it only happens with the small amp, I think its the device itself. It was a cheap unit, so I'm attributing it to that. Either way, I'm very happy with the results. Will have Evan fine tune it next time I see him.