The Wave Folder is a diode-based waveshaper with voltage-controllable gain and a 10-volt offset range.
Unlike other things that call themselves “wave folders”, this one has a glassy, almost FM-like timbre due to its origins as a sine converter. Coincidentally, this is the best sine converter available for modular synthesizers. Just plug a triangle into it with the gain at zero and you can only get something smoother from a resonant filter. However crank the gain up and you will get what can only be described as a “ruffled potato chip” wave, and then when you twist the Fold Mix control, things get pretty wild and harmonics poke out you didn’t even know existed.
This module is skiff-friendly, with a depth of only 1.5 inches.