As I said before, can you remove the harness from the car and listen to the front/rear pairs (not the home outputs) when powered from the home adapter. If the noise is still present on the 4v outputs, I'm suspicious of a production fault - it sounds to me like the 10v PSU jumper hasn't been fitted, which means the chip that powers the 4v outputs is being powered by the inputs. Erk.

Sorry, I've been busy with work, haven't had much time to work on the empeg. I'll try to remove the chassis this evening and run it off home power and check the front/rear pairs. I'll post when I get more answers.

(O|||||O)