It's a passive pickup active onboard EQ bass. The pickups are a split coil humbucker and either a single coil or a thin humbucker in the J position (looks like the OP's bass is like that). It's got a 18V preamp (stacked bass & treble) and a knowb that acts both as push-pull for active/passive and also as the treble cut when in passive mode.
Then it must have room for 2 9v batteries? leaving 18v? Sure any amp input can take that? I know of several that can't handle my twin batteried EMGs. Hence I skipped the 18v went down to "longevity" 9 v use instead. I don't lean in and thump and pop that much anymore.
18 v? That can be quite steep for any preamp to take.