I just finished the wave shaper I was working on. It is my take on Ken Stone’s take on the Triple Waveshaper by Serge Tcherepnin (module at the top right of the image).
On the oscilloscope to the bottom left you can see a sine wave from a Behringer Neutron, on the right top oscilloscope you can see the output of the 3rd wave shaper. The 3 wave shapers are linked but can be used separately.
A description of the history of the circuit can be found here.
The schematic clearly shows that the triple wave shaper consists of a repetition of 3 wave shaping circuits which can either be chained using the “JOIN” switches or via patch cables.
Each shaper folds the input wave and thus creates harmonics. It is left up to the user to externally mix those with the original signal. I’ve found that the more sections you cascade the less low frequencies you tend to hear as a result of the wave shaping. Mixing in a dry signal will give back the bottom end of the spectrum.
It could be a useful extension to this module to add a simple mixing stage that allows you to mix the input and 3 outputs (maybe make this a mixer with a stereo output and pan out the 4 parts a bit). But this can of course be achieved with an external mixer.
The circuit uses only a positive power supply. Control signals need to be 0V or positive and are therefore rectified via the diodes (1m4148 will do nicely). A rising CV1 input will increase the shaping effect, a rising CV2 input signal will decrease the shaping effect.
I 3D-printed the module’s front panel and some supports for the circuit board. I initially thought I could cram the electronics all on one small board but had to add an extra daughter board.
B.t.w. this is where the power of a 3D printer comes to bear. Once you get the hang of using one, it is dead easy to then design and print some simple support structure you need, in this case, to hold that extra daughter board. And yes, to keep things in place I’ve used some hot glue.
A short demo of the wave shaper can be seen and heard on youtube:
Note: the audio was recorded via my telephone’s microphone. It sounds a lot better coming directly from my monitor speakers.