I built this because sometimes I like to mess around with synths but don’t want to have to worry about plugging in a MIDI controller.

This is a keyboard module-controlled port of my ZS-40 patch, a four-voice polysynth loosely inspired by the CS-80. Specifically, it is based on the V2 FX version, which features an envelope-controlled ring mod and a plate reverb: https://patchstorage.com/zs-40-a-polysynth-patch-inspired-by-a-legend/

There are a few differences, beyond the mechanism of controlling the patch.

– The vibrato section was cut, due to CPU constraints.

– The patch uses something akin to a low-pass gate, instead of separate filter and VCA per voice. Because of this, the filter control is labeled “brightness” instead of frequency.

– The envelopes are based on a CV filter design, which produces logarithmic rise and fall. I think it complements the synth quite well and may do a version of the MIDI-controlled ZS that utilitzes the design.

These last two features are written about, generically, in Tips and Tricks, if you’re curious about them.

Beyond that, the keyboard module used to control the patch is set up like a guitar, so it moves up, row by row, in fourths. The “Transpose” control will change the notes displayed across the entire keyboard; the value it uses sets the lowest frequency of the keyboard.

The sustain, which is an on/off toggle, works paraphonically: you can play up to four notes, but they will all sustain as long as any one note is held.

Audio passes, in stereo, from input to output.