Next, see an actual circuit diagram (with other parts of the circuit masked out, and annotations labeling the output and trigger input): Above is a block diagram of the Snare Drum circuit.
The TR-808 Service Notes show several versions of the Snare Drum schematic. Of course, numerous TR-808 sample packs and recordings (none of which seem worth mentioning in particular) which incorporate the Snare Drum sound are extant online (&c.). It is informative to study another top-down modeling approach (built with FM synthesis in Ableton’s Operator synth ), the built-in Ableton Kit-808 drum rack. Sound on Sound’s “ Practical Snare Drum Synthesis” article shows an alternative top-down approach to modeling the 808 Snare Drum and also offers helpful commentary and insight on the behavior of the original circuit. Eric Archer’s TR-808 snare drum clone is very interesting and well-documented, and has lots of practical information for building a real circuit clone. The TR-808 service notes (Hosted by Eric Archer) contain a block diagram of the Snare Drum sound generator, the actual circuit, a discussion of its operation, and lots of supporting information. There are numerous resources out there that are worth studying and referring to, to understand how the 808 Snare Drum works. I’ll mention the resources I draw upon and some previous work on the topic, discuss the circuit, explain and evaluate my model, and mention further refinements that might improve my model. Here is my introductory work on modeling the Roland TR-808 Snare Drum in ChucK. ChucK TR-808 Emulator / Snare Drum (SD) emulation