I installed an OBP-3 preamp on my Ibanez SR375F with MK1 pickups. I'm having a couple of issues. First, my bass isn't as loud with the new preamp. It's not too much of a difference, but I thought it would be louder with the new preamp. Second, my tone doesn't seem to change when adjusting bass, middle, and treble. Third, when I grounded the battery and the preamp, no sound came out. I've tried grounding just one or the other, but same result. I ended up taping off the ground wire for both the battery and preamp, but this doesn't seem right. It only works when not grounded. I've grounded all the pots to get rid of some hissing and everything is grounded to the jack. I'm using 50k pots on the EQ and 250k pots on both of the volumes. Just to clarify, I installed the pickups first with the stock preamp and there were no issues, so I can safely rule out that. Any advice?