That Sadowsky Pre is not a simple drop in unit. You need a batt compartment and the jack needs to be side mounted as its not on the plate. There are some other units that are drop in. But they don't offer a passive option in most case without modification of the bass.
98 Ibanez SR 405, 95 Tobias Growler 4, Elrick Gold series E-volution 5, Ibanez GWB 35, Mark bass CMD 121P, TH500, Berg CN 112