edsmiata, I've seen your many threads while searching the BBS for grounding issues. It's sad to see that you're plauged. I have no idea how to help, unfortunately.

I do think I've cured my ground loop. Accidentally, of course. While testing the two decks sitting on my car seat, I placed the empeg on top of the Alpine and the sound stopped. Yup, when the sled (or docked Rio) touched the Alpine, the ground loop stopped.

So, I bought the wire, o-ring, and M4 screw (though I thought it needed an M3) to make a grounding point for the empeg sled. Haven't soldered it together yet, but maybe this weekend.