The reason why I believe this is a ground hum is because I get the standard behaviour where if I touch the strings, or jack plate, the hum disappears.

The confusing this is that on my Marshall DSL 40C, Peavey JSX 212 and Bandit 112, the sound is completely clean.  The hum occurs of ZT Lunchbox (great amp, by the way), POD HD500 and other digital processors that aren't running through an effects loop of a traditional amp.  Weird.

Edited 1 time by hoisin Oct 28 13 9:48 PM.