It is a simple universal subharmonicon patch that utilizes sequential switch instead of frequency divider for switching to different subharmonic intervals.
This will work with MIDI controlled synth (12-TET tuning only) or Eurorack (remove the quantizer for just intonation) for subharmonic sequence.
I have also done a sound demo if you are curious about how it sounds. My analog synth is playing the subharmonic sequence via MIDI, while I am improvising with a piano.
That is not a demo, thats a wonderful piece of music!
That’s pretty cool. And nice to avoid dividers - they don’t usually sound that great. I have seen a few people re-create this Moog module. Of course I do have to wonder - why not use my free “Substitute”, which is pretty compact and uses very little CV? It also does not use dividers, as it is trying to sound good. It’s only the VCO section of the Moog module, not the whole thing.
Super nice song ! The piano part is really lovely ^^
Yeah, I know a lot of people have created different versions of it. Your Substitute VCO is simple and great for use in VCV Rack, nevertheless my intention of this patch is to create a universal one that everyone with a MIDI compatible synth can use it.
Also, in my opinion, a polyphonic subharmonicon sounds better than Moog’s paraphonic one 
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You also seem to have an interesting option to quantize the subs to a regular even tempered scale. I know in mine the subs are strictly limited to being an integer division of the “main” VCO. I think the Moog is like that, too, but your option sound pretty useful.
Yeah, Not sure how your VCO tune the sub-oscillators subharmonically (using its mathematical relationship too? f/1, f/2, f/3 etc.?).
My patch basically make use of the mathematical relationship of subharmonics and 1v per octave, so -1v will be the first subharmonic etc. and the sub-oscillator is being fed with the negatively offseted v/oct value.
Works digitally, but for sure I don’t think an analog equivalent can be made without any analog artifacts e.g. voltage droop etc. 
yeah, make the period of my sub the period of the main / n. The I phase lock the subs to the main, and use a minBLEP to keep out [stuff].
In exponential land, I see how an octave down is -1, and two octaves down is -2. But what is the CV to give fs / n, when n isn’t a power of two? Guess I should be able to figure it out… some thing with logarighthms…
oh, right, another obvious inappropriate thing about dividers for this. It would be difficult (maybe?) to get a sawtooth out of one, but of course the Moog does have sawtooths.