I recently removed the frets off on an old Fender P-bass. It sounded okay but not great. In trying to improve the sound I changed to DiMarco pickups. It sounded better but not great. I'm thinking about changing out the volume/tone control. Maybe putting an active preamp like the Aguilar OBP-3. Does anyone know how to configure this type of on-board preamp to get a good fretless tone. Or, are there any other suggestions I should try?