I just installed an OBP-3 with my EMG 40J's and I have a hum. Please help!!! It also seems that when I turn up the bass or mid on the pre amp it gets really loud and overdrives my amp. I have it set up vol\vol\mid\stacked bass & treble with 25K pots for the volume and 50K pots for the pre-amp. Every connection is soldered and covered (no exposed wires).