Issue: the clock in dont work with VCO pulse or other low voltage devices.
Solution: a voltage shifter to bring the clock to 15V, with a SPST or DPDT switch to break the output signal from the voltage shifter by usingf internal clock..
supported by: http://electro-music.com/forum/viewtopic.php?p=395267#395267
Building:
DPDT switch
i have replaced the ext.start Input jack with a SPST switch, and break only the output signal from the voltage shifter
