Here we have what Befaco say is “a harsh and funky take on an additive oscillator” as it has individual harmonics or partials and VCAs to modulate them. However the idea of harmonics here is replaced with 6 octaves of square waves. It’s an analog design with a triangle core oscillator that through frequency doublers give 6 octaves to work with, each turned into squares that respond to PWM. An onboard mixer allows for blending these squares, you can break out into new tones with self patching, or make multi-layered wide frequency spanning voices from the individual outs.

Octaves VCO website, manual etc // https://www.befaco.org/octaves-vco/