Looking for help with my dilemma. I have two Deluxe Fenders that I love and use to gig regularly. One Jazz 9v and one Precision 18v. With my amp set for the J bass and switching to the P, it becomes very over driven. Resetting on the fly during a show is problematic because we run sound from the stage. Keeping a similar level in the mix after changing the amp is difficult. To even them out, is there any mod to a bass I could do? Or a device I could use in line? Is it as simplistic as pulling one of the batteries out of the 18v bass?