My bass constantly has a hiss with electronic interference beeps/fuzzes/noised. When I'm playing loud with a band obviously you can't hear it but when I'm not playing it's loud enough to be pretty annoying. It also doesn't matter whether I'm touching anything on the bass or not. This is a 2006 sr506 and I notice that the control cavity is painted black which I would assume is shielded paint but it doesn't sound like it's working. Would covering the control cavity, pickup routes, battery route, and their covers with shielding tape be enough? How would I go about star-grounding the bass? Note that I have my pickups going directly to the jack. so all the ground wires are on that. Any help is much appreciated.