I read somewhere about how Frank Zappa put EQ circuits directly into his guitar to give him massive amounts of gain.

Any ideas how to go about this?
My Gear:

Epiphone Les Paul (Custom Alpine White)
Austin Sessionmaster
Martin D-15 Acoustic
Fender Jaguar (Reissue)
Antique 1968 Fender Precision Bass

Crate Acoustic 15w
Hartke 25w