Sustained (ADSR/ASR) envelopes require a gate argument: gate=1 opens the envelope, gate=0 triggers release

Fixed-duration envelopes (Env.perc, Env.triangle) have a known total time. Sustained envelopes (Env.adsr, Env.asr) do not — they hold at the sustain level until a gate message signals release. The synth must declare a gate argument (default gate=1 so it starts immediately). Sending synth.set(\gate, 0) or synth.release triggers the release stage. After release completes, doneAction:2 frees the synth. The four ADSR parameters: attackTime (silence to peak), decayTime (peak to sustain amplitude), sustainLevel (fraction 0–1), releaseTime (sustain to silence).

Examples

x = {arg gate=1,freq=440; SinOsc.ar(freq)*Env.adsr(0.01,0.4,0.7,2).kr(2,gate)}.play; x.set(\gate,0); // or x.release

Assessment

Build a simple ADSR synth with gate control. Trigger it on and hold for 3 seconds, then release. Verify it frees itself.