My MIM Jazz Bass buzzed a little when I first got it. It also proved to be pretty susceptible to banks of lights, etc. To cure this and beef up the tone, I had a set of DiMarzio Ultra Jazz pups installed. They are humbuckers, potted in what looks like epoxy. Now it buzzes worse than before. Here are the facts as I know them: The tone pot is grounded to the bridge. The buzz stops when I touch the strings or control knob plate. Running an additional wire from the control plate to the bridge has no effect. Reducing the volume of a pup doesn't increase the buzz, it gets softer as the overall volume decreases. Using a ground lift does no good. I figure the buzz is worse because these pups are hotter than the originals. My local guitar tech says he can reverse the polarity of one or both pups. Anybody else have some bright ideas? I'm fresh out.