Envelopes: shaping a note in time
ADSR — the four-stage contour that turns a steady drone into a pluck, a stab, or a pad.
Everything so far was frozen in time — but no real instrument holds still. A piano note slams in and fades; a bowed string swells. What changes is (mostly) loudness over the life of one note, and the tool that draws that contour is the envelope. Trigger a note and the envelope runs its course; on nearly every synth since the 1970s it has four stages — ADSR.
The four stages
- Attack — time from silence to full level after the note starts. Instant = percussive hit; slow = a swell.
- Decay — time to fall from that peak down to the sustain level.
- Sustain — a level, not a time: where the sound sits for as long as you hold the note. The only stage measured in loudness.
- Release — time to fade from the sustain level to silence after you let go.
Hold the note button — attack, decay, then it parks at sustain until you let go. Drag the handles (or use the sliders) and hold again. The two presets are the two archetypes: every sound you will ever design sits somewhere between the pluck and the pad.
Pluck vs pad: the two archetypes
A pluck is instant attack, quick decay, zero sustain — all the energy up front, like everything struck or plucked in nature. A pad is the opposite: slow attack, high sustain, long release — no transient at all. When a sound feels wrong in a track, the envelope is the first suspect: the same oscillator reads as bass stab, key, or string wash purely from this contour.
Every device in this catalog carries this exact lesson on its AMP page — the amplitude envelope. The knobs are literally labeled with the four stages (plus HOLD, an extra stage between attack and decay that Elektron favors for drums). Open ATK on your machine and you are holding this lesson: