So I'm looking into some mods for my Blacktop P. I want to install an active preamp and change controls from V/V/T to Master Volume - Blend - Stacked Bass/Trebble. I'll admit that I don't know a lot about electronics but I assumed the tech at my local music store did. I explained what I wanted to do and he asks if I wanted to change out my pickups as well. I said no. "Are they active?" I said no. "Well I'm not sure that would work. I've never heard of trying to put an active preamp in a bass with passive pickups." Thinking I probably am not going to ask them for help with the mods now. Probably buy one of the prewired Bartolini harnesses where I basically just have to make a couple of solders to connect the pickups.