Tiptop Audio RS909 is an analog drum module for the modular synthesizer. The module is the TR-909 Rimshot Generator in Eurorack format.

original T-Bridge oscillator circuit of the TR-909

The sound comes from three T-bridge oscillators, which generate damped sine waves, whereby the pitch of two oscillators can be adjusted manually. The mix of the oscillators is controlled by a VCA, whose gain is controlled by an envelope generator, which also provides the typical attack sound.

Trigger/Gate & Accent Input

RS909 can be triggered via the gate input with trigger/gate signals from the step sequencer, clock divider or any other pulse/clock source. Accent In is a versatile connector that processes both CV and gate signals for continuously changing dynamics.