Hi guys. I recently bought a beautiful Carvin LB70P bass on Ebay. Mint condition, great price, great sound, everything is perfect except for two tone controls. The seller mentioned that the midrange knob was hard to turn. Oh yeah, you can turn it, but it takes alot of finger strength to do it, but it still works fine other than that. However, the seller did not mention that the treble knob was totally stripped. It turns all the way around without stopping and will short out and crackle during part of the turn. The treble EQ does not work well either. But if I set it to the right spot, it works fine and will not short out, but I'm not able to adjust it after that. My treble is basically shot. Question: Do I need a new Carvin preamp, or can I have a local guitar tech just replace the pots/posts or some other simple fix? I don't mind paying to replace the pots and for an adjustment, I just don't want to buy and pay to install a new preamp. Thanks.