Amp Envelope — ADSR
Attack, Decay, Sustain, Release. The shape of a note.
ADSR — the shape of every note.
// WHAT IT DOES
An tells the amplifier how loud the note should be over time. The classic shape is : , Decay, , Release.
Attack is the time it takes to climb from silent to full volume after you press the key. Decay is how long it takes to fall from peak to the sustain level. Sustain is the loudness it sits at while you hold the key. Release is how long it takes to fade to silent after you let go.
Different ADSR shapes give you radically different note characters. Short attack + short decay + zero sustain = a pluck. Long attack + high sustain + long release = a pad.
- • ADSR is the universal language of envelopes. Every synth uses it; every drum machine; every .
- • Most 'wrong' patches are wrong because of the envelope, not the oscillator.
- • Tiny envelope changes (5 ms more attack) can turn a sound from harsh to musical.
// SEE & HEAR IT
▸ The envelope opens the filter on attack, settles at sustain, closes on release. Big ENV + short DEC = the classic synth pluck.
▸ HOW IT WORKS
- • Attack longer than ~30 ms removes the percussive 'thwack'.
- • Sustain 0 = note dies on its own; sustain >0 = note holds.
- • Release determines how the note overlaps with the next.
▸ WALKTHROUGH (4 steps)
- 1. DO: Init synth. Set A=0, D=0, S=1.0, R=0.5. Play and hold.▸ LISTEN: Instant on, holds, fades out on release. Organ-like.
- 2. DO: Set A=0, D=0.2, S=0, R=0.2. Play.▸ LISTEN: Pluck — drops to zero even while holding.
- 3. DO: Set A=2 s, D=0, S=1, R=2 s. Play.▸ LISTEN: Slow pad swell in and out.
- 4. DO: Compare 5 ms vs 50 ms attack on a saw lead.▸ LISTEN: 5 ms feels punchy; 50 ms feels rounded.
▸ COMMON MISTAKES
- ✗ Forgetting release is zero on a 'pluck preset' you're trying to use as a pad.
- ✗ Confusing decay and release — decay is held-key dynamics, release is -key-up.