Hmm... you touch the RCA cable to the heat sink and voila, no noise. SO... Cut away a bit of insulation on one of the RCA cables, and try touching a wire from the stripped cable to the heatsink. IF you get all 4 channels, and no noise, make it permanent. if it doesn't work, use some electrical tape to fix up the RCA cable.
I don't know why this would work (electronically speaking), but if it does, you're golden.
Brian
