(yet another) Vai/Jem one-off ?
i was paging through the new Guitar World (the yellow one with the Chili Peps cover) and there's a DiMarzio ad toward the back where Steve Vai is holding a mirror-topped Jem with an extra volume knob and three micro switches. the fretboard might have some l.e.d. dot markers also. there is also no truss rod cover on the headstock.
i figure the extra vol knob is for the acoustic piezo doo-dads in the whammy bar, but the switches i have no idea. and don't forget that mirror top. i can't recall seeing this model as a "production" type; but Mr. Vai likes to tinker, and i'm sure Ibanez gives him a blank check.