Hum with VPI SDS Classic 3

I experience a hum thru the speaker when I start my turntable connected to the SDS (always keep switch on table "on"). I plugged the table directly to outlet and no hum. Has anyone solved this without giving upthe SDS?
Sounds like a ground loop. Try plugging the SDS into another socket. You can always lift the ground pin using a cheater plug, although this may be an electrical code violation.
I had some hum with my SDS and Classic 1. The SDS was to close to the TT. When I moved the SDS further away from the TT the hum went away.