If you like the sound of your bass right now, with the stock pickups, then, an onboard preamp will be the way to go. A floor pedal, well- you'll still hear the difference between the larger pickup on the Music Man, and the J-bass and the difference may still be an issue.... some onboard preamps have a gain control, and if you adjust it to match the output of your MM, that could be the solution. I just installed a "Tone Monster" pre on one of my basses. It costs about 60 bucks, and sounds killer. I liked it so much, I bought another for a different bass. They sell them in many configurations. Just to be clear- I own basses with complete Alembic circuits, and full EMG EQ systems, a legendary Stars preamp like is in Marcus Miller's Jazz, and a few others. the Tone Monster sounds great.