Hi buddies, I play a Cort Artisan B4 with the Bartolini MK1 pickups and preamp. It has the push/pull volume knob. Upper position cuts the eq, just leaving the pickup balance and volume control. Lower position enables the eq. With the eq enabled, I hear a madly distorted sound when I play. It's like a SSSHRHHRHSHSHSH, also when I touch any of the eq knobs. Did anyone had this problem with this bass or any other with similar electronics? Any suggestions to fix it by myself? Or should I ask for professional help? Thanks!!