Hmmm, in my Jeep (2000 TJ) I get a bit of alternator whine with my current CD player (no empeg yet). I have been blaming it on the Jeep wiring. You might want to try running the main power for your empeg directly from the battery (which I plan to do when I get my empeg) and see if it helps. Or, like someone mentioned just run it off AC to test.

-Mike