Picked this up yesterday. It looks nice, needs a setup, not a huge fan of the inlays but it's a cool 7 string, cool body and headstock. The problem: it's only working in passive mode, I changed the battery, no luck, looks like I am going to have to toss in another preamp. Going off of the pictures of the knob layout, what would you recommend? I like a warmer sound with some growl, not too modern and hifi sounding. This bass actually sounds surprisingly good in passive mode but I only have volume control and pickup selection. Thanks for the assistance fellow audiophiles.