Subharmonicon Emulator

I was inspired by Omri Cohen’s video “Let’s build the MOOG Subharmonicon in VCV Rack”. I enjoyed experimenting with the patch, but there are a number of key differences from the real thing that I wanted to rectify:

– The hardware has 6 true VCOs, whereas the emulator has only 2 and uses the Count Modula Frequency Divider to create the subs, which forces the subs to be square waves, and also can introduce aliasing.
– The emulator does not replicate the unusual hardware AD EGs – the EG cannot retrigger during Attack, but can retrigger during Decay.
– The PWM implementation is different. The emulator uses Sub 2A to modulate VCO1, and Sub 1A to modulate VCO2. The hardware uses Sub1A on VCO1 and Sub2A on VCO2.
– The emulator is missing a number of features that are important to the workflow of the actual hardware, such as EG Hold, Next Seq, etc.

So I decided to try to create my own emulator from scratch, with the goal of emulating the actual hardware as closely as possible. (Disregarding the fact that the filters likely have very different sound). I even opted to create a patch bay so that you can patch the emulator much like you would the hardware, without worrying about displacing a cable that was integral to the emulator.

One key constraint is I wanted to use only free plugins. That ruled out the Slime Child Substation plugin, though it looks and sounds awesome. Here is the list of plugins required:

– JW-Modules
– Count Modula
– Vult Modules Free
– Bogaudio
– Submarine
– manikk Free Modules
– AS
– Aria Salvatrice
– dBiz
– Frozen Wasteland
– 23volts
– Alikins
– VCV Core
– PackOne (Stoermelder)
– Frank Buss
– Grande

I didn’t worry too much about adding additional functionality, though I also wanted to maintain some of the constraints of the actual hardware. I opted not to use Squinky Labs Substitute because it has a single V/Oct input that controls all 6 oscillators. I could have used two Substitute modules, but I didn’t want to be tempted to use 4 VCOs with 8 Subs – I wanted the “restriction” of 2 VCOs with 4 subs.

I tried to minimize the footprint so that you could work with the entire functional part of the emulator at a reasonable zoom level. I’m able to see and access all user controls (the top two rows) at 100%. Due to the patch bay, there is a tremendous amount of “plumbing”, and I did my best to minimize cable obstruction of important modules. I especially wanted to keep the patch bay clear.

I did my best to label everything clearly and consistently. I included extensive documentation in the bottom row of the patch. The documentation includes 4 main sections:
– A list of Subharmonicon features that are missing or changed in the emulator
– A list of emulator enhancements that exceed what is in the Subharmonicon
– A description of the label color scheme to help navigate the emulator
– A brief description of all the patch bay inputs and outputs

The uploaded emulator patch does not produce any sound until you set appropriate controls as you would in the actual Subharmonicon. I highly recommend reading the Moog Subharmonicon manual –

This is the 2nd version of my emulator. The first version was published in the VCV Community at

Version 2 actually reduces the footprint a bit, while at the same time I extended the patch bay to include a post quantizer send/return. My intent is to allow patching in a 2nd quantizer that does nothing but convert the output of the built in quantizer into just intonation based on the currently playing chord, as opposed to using a fixed key note for JI. I hope to post a patch and video about this soon.

The video demo is a patch I created with the emulator as the base. It uses the patch bay and a few additional modules to start/stop the composition, and automatically adjust various emulator controls for different scenes within the composition. I use the patch as accompanyment to a Native American flute performance. The demo patch also uses Valhalla Supermassive delay/reverb behind the scenes in my DAW (Reaper)

I’d love to hear about your experience with the emulator if you download and experiment with it.

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  • Category: Other Synthesizer
  • Revision: 2.0
  • License: Do What The F*ck You Want To Public License
  • Views: 436
  • Modified: 8 months ago
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