confusedmachines

http://www.confusedmachines.com/

"This site will one day detail modifications (mods) to all sorts of electronic instruments. For now however, it documents mods of my Roland TR-606, turning it into a Roland TR-666. The TR-666 is a beast that is part 606, part 808 and part devil.

Basically, as you can see from my pictures, I've added 19 new knobs (one is internal), and a switch to a Roland TR-606 to allow for some pretty smooth or freaky sound control. The new controls are:

BD. Tune, Tone, Decay, Pitch. (also internal max. decay limit)
SD. Tune, Snappy, Decay
HT. Tune
LT. Tune, Pitch
HH (common). LPF, BPF
OHH. Decay
CHH. Decay
CY. BPF (common to HH also), BPF (separate), Decay
System Noise Amount.
Tempo Fine Tune"

Title link takes you to more info including samples and a close-up of the knob box.
via mc in the comments of this post.