Like the subject, or, rather, the pickup blend pot. When its in the center, there's a little bit of hum, and when I turn it away from the center (either direction) the hum gets almost unbearable. When I dial the magnetic pups out altogether with my piezo blend, the hum goes away altogether. What's weird is that this has just begun to happen, and nothing on the instument, other than strings has been touched. Any Ideas?