ok here is my weird problem: I have a set of EMG jazz bass pickups installed with a EMG-EXB in one of my basses. It has worked great until yesterday. Now it still works, sort of. When I turn up the EMG-EXB it only boosts the signal slightly(no apparent bass or treble boost like it is supposed to) and I get a LOT of hissing noise. the same noise occures to a lesser extent when I turn up the tone control(towards a "cleaner" sound) I also notice that I also get noise when I turn both pickups down, or to a lesser extent if only one is turned up. Any ideas?