Another good way to mess up your audio (and CV signals) is with the A-116 VC Waveform Processor module.
After the input amplifier, the signal goes through two parallel processors: a clipping circuit, and an asymmetrical amplifier.
In a way you could see this module as a cut-down version of the A-137-1 that i reviewed in an earlier post.
Cut-down, but still very effective...
The processed signals are added together and sent to the output.
Clipping-Level and Symmetry amounts are manually controllable, but can also be modulated by control voltages like ADSR's, LFO's, Noise, etcetera.
It is a fun module to experiment with, although i haven't used it in a while.
Take a look at the video by Hawklord2112 that gives a nice impression of what this module can do.
Video: A-116 Demo
" basic functions of the A116 VC Waveform Processor from Doepfer. "
Find more of his videos at http://www.youtube.com/hawklord2112