Modulation
ADSR
Envelope generator — shapes how a note rises and falls over time.
Learn about it in Envelopes & VCAs: how notes start and stop
How it works
When the GATE input goes high (a key is pressed), the output rises to 1 over the Attack time, falls to the Sustain level over the Decay time, and stays there while the gate is held. When the gate goes low (key released) it falls to 0 over the Release time. The graph shows the current shape.
Inputs
| GATE | Note on/off. Anything above ~0.3 counts as “on”. Patch Keyboard GATE, Sequencer GATE, Quantizer TRIG, a Clock output… |
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Outputs
| OUT | The envelope, 0 to 1. Patch into VCA CV to make notes, and Filter CV to make them “bloom”. |
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| INV | Upside-down copy (0 to −1) — for things that should dip when a note plays (ducking). |
Knobs and switches
| A | Time to rise from 0 to full. |
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| D | Time to fall from full down to sustain. |
| S | Level held while the gate stays high. 0 = a plucky note that fades even when held. |
| R | Time to fade to 0 after the gate goes low. |
Lessons that use the ADSR
Each one opens as a working patch in the synth.
- 02 · Envelopes
- 03 · Subtractive Synthesis
- 05 · Mixer: Fat Sounds
- 07 · Clock & Sequencer
- 10 · Space: Delay & Reverb
- 11 · Noise: Wind & Hats
- 12 · FM: Audio-Rate Modulation
- 14 · Bitcrusher: Lo-Fi
- 15 · Vowel: Make It Talk
- 16 · Chorus, Phaser, Flanger
- 17 · Wavetable & PWM
- 21 · Generative Melodies
- 24 · Scale/Offset: Signal Surgery
- 25 · Chords & Arpeggios
- 26 · Polyphony: Play Chords
- 29 · Switch: A New Melody Every Bar
- 31 · Turing Machine
- 37 · XY Pad: Play by Touch
- 41 · Gamepad & Phone Tilt
Words to know
- Envelope — A one-shot shape that rises and falls each time a note is played.
- ADSR — Attack, Decay, Sustain, Release: the four stages of the most common envelope.
- Modulation — Using one signal to change another over time.