hi. so now i have some active washburn bass pickups i got off ebay. they're bartolini customs. i already have a circuit made with volume, tone, and blend. but that's passive. i'm wondering if there's a way to make these pickups run passive without shounding like s**t. or a way to make my circuit run active by adding a battery or something. just because its so expensive to get an active preamp for basses. if anyone could help at all, with changing the electronics of finding a cheap preamp, that would be awesome! thanks a lot