I built a little single transistor distorion curcuit. Pretty easy. The schematics are on my blog here:
http://blog.jonnay.net/archives/504-Tha ... Crew!.html
The devilfish has 2 different kinds of distortion, overdriving the input to the VCF, and what is called a 'muffler'. THe muffler according
to the devilfish site is a soft-clip distortion effect, with 2 settings, (including off).
Doing this soft clip distortion (or at least one similar way to do it) would be to put 2 diodes before the volume pot, one of them reverse biased, and set to ground. I'll post some schematics to the wiki.