Envelope

• Dynamics
• Since 0.2.0
• adsr
• gate
• shape
• dynamics

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An envelope shapes how loud a sound is over time. It listens to a gate: when the gate turns on the sound rises, and when it turns off the sound dies away.

What it does#

The envelope multiplies the audio passing through it by a gain that follows an attack, decay, sustain and release shape. A rising edge on Gate starts the envelope. Depending on Type it can be a full ADSR (attack, decay, sustain, release), an AD (attack then decay to zero) or an AR (attack, hold while the gate stays on, release). Curve bends every segment between concave, linear and convex. It can loop for as long as the gate is held.

It is a gain stage for audio, not a control signal: put it on the sound path.

Events#

The done outlet sends an event: it is 1 for one block when the envelope finishes and returns to silence, that is when the release ends after Gate turned off or an AD cycle completes, and 0 otherwise. A looping envelope never finishes, and a Gate that rises during the release restarts it without a done. Cable it into a trigger input, such as Counter or Sample and hold, to advance something each time a note has fully died away.

When to use it#

Use it to turn a continuous source such as Oscillator into notes, to make plucks and swells, or to build rhythmic gating. The Polyphonic instrument already has an envelope for each voice.

Ports#

Parameters#

Attack (attack_ms)#

The time, from 0 to 10000 ms, taken to rise to full gain after the gate turns on.

Decay (decay_ms)#

The time to fall to the sustain level in ADSR, or to zero in AD. It applies to the ADSR and AD types.

Sustain (sustain)#

The held gain while the gate stays on in an ADSR envelope, shown from 0 to 100 % of full gain (stored as a fraction from 0 to 1).

Release (release_ms)#

The time to return to zero after the gate turns off. It applies to the ADSR and AR types.

Gate (gate)#

The trigger, on (1) or off (0). Turning it on starts the envelope and holding it on keeps it running. Bind it to a momentary button or toggle in a Frame, or cable a control signal in: it counts as on from 0.5.

Type (type)#

Chooses ADSR, AD or AR. It is a discrete choice.

Curve (curve)#

Bends the segments, from -1 to 1. Zero is linear; values on either side give concave or convex curvature.

Loop (loop)#

When On, complete envelope cycles repeat while Gate is held.

Retrigger (retrigger)#

On a rising Gate edge, either restart from the current gain (smooth) or reset to zero first.

Loop hold (hold_ms)#

The time the held part lasts in each repeat of a looping ADSR or AR cycle. It is shown only while Loop is on.

Tips#

• A short Attack with a medium Decay and zero Sustain makes a pluck.
• Looping an AD envelope is a quick way to make a repeating sound for testing effects.
• The envelope works on any channel count.
• done is a one-block pulse, like Compare in Trigger mode. Cable it into a trigger input; to sequence notes, let it clock a Counter that picks the next pitch.

See also#

Oscillator, Polyphonic instrument, Compressor.

Help patches

Each help patch is an ordinary Toy that teaches one idea. The diagram shows the Patch; the preview shows its Frame. Open it in TuneToys to play and edit it.

1. Shape a tone with attack and release

beginner Teaches: attack_ms, decay_ms, sustain, release_ms, gate

An ADSR envelope played from a gate button.

Connections as text

• Oscillator audio output connected to Envelope audio input
• Envelope audio output connected to Patch outputs audio input

• Press and hold Gate. The tone rises over Attack, falls to Sustain over Decay, and holds.
• Let go and it fades over Release.

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2. AD and AR shapes, and curve

intermediate Teaches: type, curve

Switch envelope type and bend the segments.

Connections as text

• Oscillator audio output connected to Envelope audio input
• Envelope audio output connected to Patch outputs audio input

• AD ignores Sustain and Release. AR ignores Decay and Sustain.
• Curve bends every segment: negative, zero and positive values give different shapes.

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3. Loop the envelope and retrigger

advanced Teaches: loop, hold_ms, retrigger

A looping envelope that repeats while the gate is held.

Connections as text

• Oscillator audio output connected to Envelope audio input
• Envelope audio output connected to Patch outputs audio input

• With Loop on, the envelope repeats for as long as Gate stays on.
• Loop hold sets how long each repeat stays at full level.

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4. Count finished notes

advanced Teaches: release_ms, control-lanes

A square LFO gates an envelope; each time the release finishes, the done outlet steps a counter that opens a filter one notch further.

Connections as text

• Oscillator audio output connected to Envelope audio input
• Envelope audio output connected to Filter audio input
• Filter audio output connected to Patch outputs audio input
• Control LFO control output connected to Envelope @gate input
• Envelope done output connected to Counter trigger input
• Counter control output connected to Select lanes control input
• Select lanes control output connected to Scale control input
• Scale control output connected to Filter @cutoff input

• The square LFO drives the gate socket: high opens the envelope, low starts the release.
• done is 1 for one block when the release ends; it clocks the counter like a trigger.
• Lane 1 of the counter (count / limit) is scaled and cabled into the filter cutoff, downstream of the envelope.

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Related nodes

• Oscillator Selected waveform kernels, continuous morphing, harmonic shapes and phase/gate control; an optional MIDI input plays notes in the Toy's tuning.
• Polyphonic instrument Eight owned, velocity-sensitive oscillator voices with ADSR, sustain and MPE, played from a MIDI cable in the Toy's tuning.
• Compressor Peak/RMS compression with a sidechain key input, detector filtering, hold, adaptive release and channel linking.