Recently i bought a set of mim fender jazz pickups i dont have a jazz bass or anything but $10 why not. So now i have an idea to put them in my epiphone thunderbird not taking out the soapbars but having both sets. Putting the bridge one in between the soapbars and the neck one above the neck pickup. Then i wanna get separate set of knobs for the jazz pickups and a switch to go back and fourth from the jazz pickups and soapbars. Is this possible and has anyone done something like this?
You can put a on/on switch to seperated the two sets of pickups. As far as knobs go you can install stacked pots so you don't need to add more holes. Or add more holes with new pots. I'm sure there are many more options like push/pull pots..ect.. You could also add another output jack, then you could run your bass into two amps. Imagine the tonal possiblities.
It's entirely possible. You'll obviously have to route for the additional pickups, and drill additional passages for the wiring. This is, obviously, not reversible. Electrically, you could use mini-switches, or push-pull switches, or stacked knobs, or just drill another hole and run four volumes to the jack. The latter would be my choice - ditch the tone control and run four volume pots.
The pickups arent here yet but i think i will do a combination of both of you and have 4 volume pots and an on/on switch but theres very little room in the cavity so i might have to route out some more. And where can i get an on/on switch?
Off the top of my head stew mac. If there isn't much room you can use concentric pots (stacked). Is there 3 pots on your bass? If so just switch out your old pots and add 3 stacked. You can have one for neck pups, 1 for bridge and one for duel tone. Or something like that.