Purpose

Envelope is a control-signal AHDSR envelope generator: attack, hold, decay, sustain, release, rendered at sample rate as a control stream. It is not audio DSP; wire its output into any parameter that should follow a gate — filter cutoff, effect depth, a visual. Retrigger laws, looping, and ping-pong extend it from a note envelope into a cyclic modulation source.

Use

Wire a gate or trigger source into the gate or trigger input and the value output into the parameter to modulate. Set the AHDSR stage times, choose a Retrigger law for overlapping gates, and turn Loop on to cycle the envelope while the gate is held.

Inputs and outputs

• Input 0: rate — control stream that scales stage times. Optional.
• Input 1: phase — external phase input. Optional.
• Input 2: trigger — fires the envelope on a rising edge. Optional.
• Input 3: gate — holds the envelope at sustain while high, releases when it falls. Optional.
• Output 0: value — the envelope level.
• Output 1: phase — progress through the envelope.
• Output 2: cycle — running cycle count when looping.
• Output 3: pulse — fires when the envelope ends a pass.
• Output 4: active — whether the envelope is running.

Controls

• Attack, Hold, Decay, Sustain, Release — the AHDSR stages. Times in seconds up to 60; Sustain is a level.
• Amount — output scale, bipolar so an envelope can also pull a value down.
• Curve — segment curvature, from snappy exponential to slow-starting shapes.
• Retrigger — what a new trigger does mid-flight: restart from zero, legato (ignore while running), or from_current (restart from the present level).
• Loop — cycle the envelope instead of resting at sustain.
• Pingpong — alternate direction when looping.

Notes

• from_current avoids clicks when triggers arrive faster than the release finishes.
• Loop with short stage times is an alternative LFO with an envelope’s shape vocabulary.
• The pulse output can chain into another control op’s trigger input to build multi-stage modulation.

Ports

Inputs

• rate row
  control_f32_v1
• phase row
  control_f32_v1
• trigger row
  control_f32_v1
• gate row
  control_f32_v1

Outputs

• value row
  control_f32_v1
• phase row
  control_f32_v1
• cycle row
  control_f32_v1
• pulse row
  control_f32_v1
• active row
  control_f32_v1

Parameters

Attack (Attack) Float op('envelope').par.Attack

Default:

0.01

Range:

0 to 60

Hold (Hold) Float op('envelope').par.Hold

Default:

0

Range:

0 to 60

Decay (Decay) Float op('envelope').par.Decay

Default:

0.2

Range:

0 to 60

Sustain (Sustain) Float op('envelope').par.Sustain

Default:

0.7

Range:

0 to 1

Release (Release) Float op('envelope').par.Release

Default:

0.4

Range:

0 to 60

Amount (Amount) Float op('envelope').par.Amount

Default:

1

Range:

-16 to 16

Curve (Curve) Float op('envelope').par.Curve

Default:

1

Range:

0.05 to 8

Retrigger (Retrigger) Menu op('envelope').par.Retrigger

Default:

2

Options:

restart, legato, from_current

Loop (Loop) Toggle op('envelope').par.Loop

Default:

Off

Options:

Off, On

Pingpong (Pingpong) Toggle op('envelope').par.Pingpong

Default:

Off

Options:

Off, On