I have a preamp from a 2013-ish (i.e. the newer ones with the passive tone control) American Deluxe Jazz Bass that I'd like to install in my Fender MB-5. The preamp has two battery leads, but can these preamps be run on only 9V, or do they require the full 18V? I ask because the MB-5 has a small body, and I'd prefer to only rout out one battery cavity if possible. It's already going to be tight to get all of the components in as is, so I definitely can't squeeze one in the existing control cavity. I realize a different pre would probably be a better choice, but I have this one already so I'd like to see if I can make it work.