This consists of a triangle VCO carrier and a modulator. The complex overtones generated by FM modulation are sent through a wave folder circuit to add additional overtones, producing a distinctive sound. This module is important in determining the basic character of the sound of volca modular.
This section consists of two functions (envelope) generators. In addition to an AHR generator with attack, hold, and release, there’s a Rise-Fall generator, also known as a slope generator, which not only applies time-varying change to the sound but also lets you patch the end trigger out back into the trigger in as a loop, making it usable as a VCO or LFO.