Marcus Retro Pre W/ MM Humbucker

[JCsuckybass]

Hi,

I have a project bass I am currently working on that has a John East Marcus Retro preamp with nordstrand j pickups. I want to add a music man style humbucker to the bass like these atelier z basses ATELIER Z GUITAR WORKS｜KENJI JINO HINO .

Can anybody give me some ideas? So far I have figured out that I need a passive blend added to the whole configuration for it to work properly to mix all the pickups equally. I am not sure if I can just add the musicman humbucker to the screw terminal where the bridge pickup goes, or if I wire the additional passive blend to the terminal somehow. Thanks.

[JCsuckybass]

Ok, I thought about just adding a switch so the humbucker is attached to just the neck or just the bridge. Does anybody know if there are any schematics out there for that?

What if I just had a stand alone volume for the humbucker?

Any ideas?