The CGS585 is a non-linear modifier which can transform a sawtooth wave into a sine wave.

This module incorporates three independent waveshapers for modifying synthesizer waveforms or for processing signals from pre-amplified instruments. Although originally designed as a waveshaper for the CGS507 1973 VCO, this module has been found to be an excellent modifier of electronic and acoustic sounds, and is highly recommended for subtle timbral modifications beyond the range of simple oscillator/filter patches.

Of course, it's uses go beyond this. When used in series, they can be used to add folds to the wave shape. Each extra wave shaper you put in series adds a fold to the waveform. As such, quite a lot of tonal variety/harmonic enrichment can be achieve.

The [JOIN] switch between stage 1 and stage 2 connects [DC OUT 1] to the input section of [WAVESHAPER 2] while the [JOIN] switch between stage 2 and stage 3 connects [DC OUT 2] to the input section of [WAVESHAPER 3] allowing the signal patched to [INPUT 1] to pass sequentially through all 3 wave shapers. The level of the signal through all 3 stages is defined entirely by [IN 1] level control.

The level controls in each stage only affect the input patched to that stages [IN x] jack and do not affect the level of the 'joined' signal.