The InstrumentOutput module is used in instruments, to send the left/right audio data computed by the modules within the instrument out of the instrument network.

The other function of the InstrumentOutput is that it signals when a note has been played completely, and its voice doesn't need to be computed any longer (and can thus be reused for new notes later on). This signalling is done by passing an 1.0 signal to the "Synth Done" channel if the note is complete, 0.0 otherwise. An AdsrEnvelope? is usually used to get this signal computed correctly.