I've been planning putting together a new bass and was wondering about setting it up with a passive Bartolini classic MM pup and a bridge J. I never play with the volume and tone on anything but full. If I only wanted to use one pickup at a time could I just wire the pickups through an on/off switch straight to the jack? And is there even enough room between a MM in the normal "Sweet spot" and the bridge to fit a J pickup? Am I insane for even contemplating a bass with no pots at all?
Not insane at all. The fewer knobs etc., the less there is to "go wrong", or degrade the signal from your pickups, or distract you from playing. Don't get me wrong, I love having a dozen knobs and switches to fool around with; but honestly they can get in the way of just plain playing. I've owned one bass that had a switch to select between a preamp with various controls, and a direct connection from pickup to output jack. I almost always preferred the sound of the direct connection. I also have a custom order in with Valenti for a passive P bass with only a tone pot, no volume pot.