MTI Rotophaser with Footswitch Schematics and Images

The MTI Rotophaser is a rotating tremolo horn speaker system made in Italy in the 1970s. It is similar to the top half of a Leslie cabinet.

MTI Rotophaser Faceplate MTI Rotophaser Panel Gutshot

Intended to be driven by an external amplifier, a crossover network allows the Rotophaser to be paired with an external speaker cabinet.

MTI Rotophaser Crossover

An external footswitch is necessary to operate the unit.  It is entirely possible and perhaps preferable to eliminate the footswitch and relocate some or all of the switch functions to the cabinet.

MTI Rotophaser Footswitch Control PedalMTI Rotophaser Footswitch Control Pedal Gutshot

Two separate cables feed the footswitch. One cable distributes power (120vac) through the footswitch to control motor functions (slow, fast, off)  and the other controls  speaker routing.

Without a schematic, the wiring of the Rotophaser footswitch appears to be rather complex and mysterious.

I’ve drawn up two schematics for the footswitch portion of my MTI Rotophaser, bearing an inspection sticker dated early 1980.

MTI Rotophaser Footswitch Speaker CircuitMTI Rotophaser Footswitch Power Circuit

Your questions, comments or additions to this brief exploration of the MTI Rotophaser are most welcome.