Explorations around a schematic found among old papers of mysterious origin, suspiciously similar to a datasheet sq/tri oscillator.
All that was needed was to connect the dots.
A slew limiter smoothes out how quickly incoming voltage can change, limiting it to a fixed v/sec. slope. Since time and frequency are intrinsically linked, this acts as a steep, somewhat distorted low pass filter.

When it resonates, these fixed slopes become triangle wave oscillations, giving 20% more its unique sound. Input signals can overwhelm this oscillation, making for pseudo-wavefolding and synthetic distortion artifacts. 

jfet clipping, sub and upper octaves, envelope follower, low pass gate; impressions, ideas, pleasures and pains