Hello. I had a couple of articles on drum synths. Check ftp://ftp.funet.fi/pub/sci/audio/devel/lad/drumsynth/ I built the circuit in a00*.jpg at the time when this article was fresh. The article b00*jpg mentions an earlier article. I will check that out at library. Hmm.. I coded a drum synth for Commodore VIC-20 at the time. VIC provided an audio chip with three oscillators, noise, and a common volume if I remember correctly. What I did was to modulate osc pitch and volume parameters with a fast and accurate (compared to Basic) assembly code. The drum sounds were assigned to the keys. This was about 1984, inspired by Yamaha's digital RX drum synths, not by analog drums. Juhana -- http://music.columbia.edu/mailman/listinfo/linux-graphics-dev for developers of open source graphics software