The Waveulator: Two VCA-based Clipper Saturators

[mediatechnology]

Waveulator Boards and kits with THAT ICs are now available: https://ka-electronics.com/shop/index.p ... waveulator

[capacitor]

Bump (while wrapping my head around how this works) with a minor question:

Is it possible to get a little bit of even order distortion by slighly imbalancing the signals that go into EC- and EC+?

In other words, could a simple voltage divider/trimpot at either one of those inputs add even order distortion?

I know it's likely not musically useful on a mix, but curious whether or not it's possible and how it could be done.

[mediatechnology]

Bump (while wrapping my head around how this works) with a minor question:

Is it possible to get a little bit of even order distortion by slighly imbalancing the signals that go into EC- and EC+?

In other words, could a simple voltage divider/trimpot at either one of those inputs add even order distortion?

I know it's likely not musically useful on a mix, but curious whether or not it's possible and how it could be done.

Thanks for visiting us!

You can make second/even-order and I've tried it. There are some samples in this thread.

Not sure changing the EC+ EC- will do it though: I would alter the gain of IC3B and IC4B which will affect the negative portion of the modulation waveform. Increasing the gain will provide more saturation on the bottom half than the top. https://proaudiodesignforum.com/forum/p ... php?t=1331

[capacitor]

Thank you! I was posting tired and of course that is the better way to do it.

I have a used THAT2180-DEMO to play with, which gives me a single channel to run individual tracks/instruments through. I plan to breadboard the remaining modulation portion and will give that a shot.

Thank you for this very cool circuit.

[mediatechnology]

You're welcome.

I think that scaling Ec+ relative to Ec- will affect the control scale factor but not introduce even-order harmonics.

The reason why I used differential drive was to minimize AC feed-through since the modulation waveform is half-wave rectified at twice the input frequency. I admit to never testing for this but at the cost of a single op amp per channel it seemed like a good idea.

Though not related to the Waveulator another reason for differential drive are conventional VCA applications when deep attenuation is needed where a single Ec (+ or -) approaches approximately 600 mV for -100 dB attenuation. Differential drive reduces the Ec requirement for -100 dB to 300 mV per port.

[capacitor]

Nothing to add substantively, except I wish the forum software had a thumbs-up button!