Swapping the cable should not really effect anything.

I can have just the 990 and the 7700, with one component, and one speaker hooked up, and still get the same pop.

I've had a replacement unit, and did the same thing.

Pulled all the speakers, and had the same thing.

Toslink connections only from components to 990 (NOTHING ELSE), and had the same thing.


Grounded all components and amps to the same point, and have the same thing.