It's actually a dynamics effect that when abused produces the distortion you hear. I had originally created the combinator to look for usable sweet spots and find a reduced set of parameters (from the 10 the device has) before embarking on this abuse of the effect.
Listening back to it now it's actually not that bad. Would like to get your thoughts on it and if it interests anyone.
It's also used on the master for these two (but used for its intended effect rather than being abused):