(Edit: Please skip to the latest version below.)
Here’s a test patch I put together that uses Algomorph to put VCOs through their paces.
Quick demo video, all synth no talking (recorded with the Rack engine running at 48 kHz):
I set each group of oscillators to matching frequencies and FM modulation depths. Each operator’s frequency and modulation depth, along with the set of three algorithms which all groups smoothly fade between in lock-step, are chosen to elicit interesting but not excessively noisy results from all the groups collectively. (Hence: the low modulation attenuators.)
I only include operators if they include both a PM / TZ / LFM input as well as a sync input. The included oscillators are:
- Bogaudio – VCO (sine and triangle)
- NYSTHI – TZOP, µOPERATOR
- Squinky Labs – Kitchen Sink (sine and triangle)
- Valley – Terrorform (sine and triangle)
True Frequency Modulation
- Fundamental – VCO and WT-VCO (TZ) (sine and triangle, each)
- Valley – Terrorform (TZ) (sine and triangle)
The settings for each operator:
Operator 4: [Freq - 65.407 Hz, i.e. Octave -2 & Ratio x1] [Modulation Depth - 6.6265%] Operator 3: [Freq - 196.22 Hz, i.e. Octave -2 & Ratio x3] [Modulation Depth - 6.988%] Operator 2: [Freq - 163.52 Hz, i.e. Octave -3 & Ratio x5] [Modulation Depth - 5.1807%] Operator 1: [Freq - 114.46 Hz, i.e. Octave -4 & Ratio x7] [Modulation Depth - 4.5783%] Wildcard: [Freq - 16.352 Hz, i.e. Octave -4 & Ratio x1] [Modulation Depth - N/A] [Oscillator Amplitude - 0.20482%]
And these are the three algorithms (a horizontal red line indicates a silenced operator):
Among the phase modulation oscillators (in the context of this patch and the chosen algorithms/frequencies), I find that the resulting sound can easily be grouped into 2 categories among which I believe the primary difference is the implementation of oscillator sync:
Bogaudio and Squinky Labs
NYSTHI and Valley
For now, Algomorph for VCV Rack 2 is only available as source code. That can be found through here:
See also the Algoseq version of this patch below.
Developers: Want me to add your module to this patch? Am I using your module incorrectly? Please let me know!
Everyone: If you find an interesting set of algorithms, frequencies, and modulation depths for use in this patch, please share!