My fretless Elrick with a Bart 3-band has a noticeable difference in volume when switching between active and passive (with no EQing). I'm used to this- it's been like this on my other active basses I've had in the past, IIRC. But my fretted Elrick with an Aguilar OBP-3 has the same volume when switching between active and passive. The volume only boosts when the EQ is put into use. I REALLY like this. Is the preamp alone responsible for the difference in active/passive volume (both basses have pretty much the same Bart soapbar pickups)? Is there a way to adjust it so the active volume is about the same as the passive?