Available as an assembled Module and as a DIY project.
This Module is currently available.
Quadrature Trapezoidal Low Frequency Oscillator
This module is a specialized LFO. It outputs four trapezoidal waveforms which are synchronized with each other. Each of the four knobs adjusts the duration of a different phase of each output. It requires no special parts to build.
These merchants probably sell this module. Huh?
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