Pioneer PL-400X turntable

[ppppenguin]

I've downloaded the service manual. This block diagram is the nearest thing to a schematic. If we ignore the strobe then the output of the PD1003 needs to be replaced by a variable frequency signal. Not sure what the switched resistor on pin 11 of the PA2004 is doing. Possibly some kind of range control for the F/V converter or, less likely, setting a loop time constant.

I'm making the assumption that the motor and its 3 phase driver have enough oomph to spin the platter at 78rpm without getting hot and bothered.