Ibanez Musician Club
The Ibanez Musician Bass was a line of electric bass guitars produced by the Ibanez Corporation from 1979 to 1987.
There is a good article on these basses over at Wikipedia, and it seems redundant to copy all that information here.
These wiring diagrams are first discussed here.
Some of these wiring diagrams originate at DGB Studio.
Musician MC900: Three band EQ from 1981 and earlier.
Musician MC924: Three band EQ for the 924 which are from the earlier Super-4 version.
Musician MC924 & MC940: Three band EQ for the 1982 and later version, pickup balance pot, no gain.
Schematic for the above MC924 & MC940. This is also for the 1982 and later version, with connection letters corresponding to the diagram above. Note there is a green wire "j" that comes off the eq board which does not go anywhere.