I've got an Ovation Custom Balladeer acoustic/electric, with the fet-3 preamp. I've replaced the battery, checked connections, etc., but it cuts out on me. I can't get much volume through the PA, and the sound is really muffled sounding--won't work through an amp. Plus, while plugged into the PA, the volume knob works backwards!!!

at 8 or 9, i get no volume. I have to turn it down, to around 3 to get any volume, or to 0 for a decent signal! What's going on here? are any of these problems related???
I talked to Ovation customer support, and all they said was to order a new preamp through them-- for 75 bucks.
Any help???