This is the Schematic for a DS7, a drum synthesizer module. basically, when you activate a trigger, it makes very basic noises- all analog. The Papareil Synth Labs page has some more info, but basically someone took apart the original commercial version, figured out how to rebuild it, then made the information public. I just got all the parts on Wednesday, and hopefully, with the help of the fine folks at Hive76, I'll be making noises in no time.
