Here's my predicament: I have 2 Warwick Corvette Standard basses, 1 fretted +1 fretless. They have identical EMG pickups(J's) and BTC controls. What freaks me is that the fretted will not work w/my Shure wireless system,while the fretless works fine. The problem is that when I plug in the fretted bass, I can play for a couple seconds and then it totally craps out. The sound will go from bassy and clear, to trebly and distorted,to finally nothing. I've noticed that this will happen as soon as I touch a control knob of any variety. The folks at Shure said it is due to RF in the control cavity. Does anybody know how to get rid of it?