Available as an assembled Module and as a DIY project.
This Module is currently available.
3 stage waveshaper
The TRIPLE WAVESHAPER is a non-linear wave modifier which can transform a sawtooth wave into a sin wave. This module incorporates three independent waveshapers which are useful for modifying synthesizer waveforms or for processing signals from preamped instruments.
Of course, it's uses go far beyond the use of the description above. By using each section in series you can add folds to the wave, each section adding a fold to the applied waveform. To get the best results of this action would be to use a sine wave as the source.