Yes, the LFO is produced on the processor board (lower right corner of the KLM-367 page in the service docs), and then travels to the front panel through a wire.
The LFO signal then travels across the front panel board (KLM-369) to various destinations, including the sockets with all the cables going to the pitch and mod wheels.
Locate the cable that is delivering the LFO signal TO the modwheel, cut it, and insert a switch here, so that you can choose between the original LFO signal and the extra added external LFO. You will need to lengthen the original cables to make them reach the front panel. You should also calculate, measure or adjust your external LFO´s output so that it matches the output of the original LFO.
If you set the switch to the "original" position, the original LFO will come through as you raise the mod-wheel.
If you set the switch to the "external" position, the external LFO will come through as you raise the mod-wheel.
As earlier explained: this will only work if you have the original processor board in your PolySix.
If you, like me, have the KiwiSix processor board, the modwheel does not carry the actual LFO signal; it only controls how much LFO signal the processor will mix into the VCO CV lines. It can still be useful, but not to the same extent. However: since I also have the KiwiSex modification kit installed, I also send the external LFO signal to the unused mod setting (PW LFO that is no longer directly awailable from the KiwiSix processor board). So all-in-all it is still very useful for me.
You will need to drill some holes in your PolySix, both for the switch and various controls for the external (extra) LFO. I only used a speed control pot and a bi-polar/bi-color LED, but you could install a MS-20-style LFO/MG with both speed and shape controls, in addition to a switch for square and triangle/sawtooth. Any LFO will do, actually, so you can use whatever suits you.
The LFO is actually secured to the front panel using pot brackets (I learned this from all the years of building Oakley Sound modules).
The external LFO and the switch is located the the left of the front panel, below the original LFO/MG, so that it is a close as possible to the modwheel.
Terje
Hi Terje,
Could you provide additional information as to how and where you installed the Mod Wheel switch to swap in your external LFO, please?
Thanks a lot.