this mod allows an external waveform to be inserted instead of the built in triangle wave.
sever the trace between U1-A pin 1 and R10, you have to scrape it away with a hobby knife. connect a jack to be the waveform input jack at the resistor R10 where you severed the trace, do not unsolder the resistor, it still needs to be in place, just solder the wire on the top or bottom of the board where the resistor connects à la circuit bending.
if you want the triangle to be normalized to the jack when nothing is plugged in, use the handy extra hole for C2 that connects at U1-A pin 1, and run it to the switch lug on the jack.
now you can make pan position fly all over the place just as crazily as your synth patches!
not responsible for any damage or injury.