instruo/ceis2

cèis[2]

Instruō

A fully analogue voltage-controlled ADSR envelope generator with per-segment gate outputs, CV control over all four stages, retriggerable attack, hold mode for slew limiting, and variable linear-to-exponential envelope shape.902

Capabilities 2

ADSRadsr
Classic four-stage Attack-Decay-Sustain-Release envelope with fader and bipolar CV control over each stage.902
Envelope Generatorenvelope-generator
Four-stage ADSR with CV control over all segments, per-segment gate outputs, retriggerable attack, and hold mode for slew-limiting use.902

Jacks 12 (6 in / 6 out)

NameSignalVoltageDescription
Inputs (6)
Attack CV InputcvBipolar CV input summed with the Attack slider to modulate attack time; with negative CV the minimum time reduces to approximately 0.8 ms.902
Decay CV InputcvBipolar CV input summed with the Decay slider to modulate decay time; with negative CV the minimum time reduces to approximately 0.8 ms.902
Gate/Trig InputgateAccepts gate or trigger signals to initiate envelope generation; behavior depends on the Gate/Trig Toggle mode setting.902
Release CV InputcvBipolar CV input summed with the Release slider to modulate release time.902
Retrigger InputtriggerRetriggers the attack stage from the envelope's current position without waiting for a new gate signal.902
Sustain CV Inputcv-10V to 10VBipolar CV input summed with the Sustain slider; in Hold Mode it becomes a signal input whose level is slewed by the attack and decay parameters.902
Outputs (6)
Attack Gate Outputgate≤10VOutputs a 10 V gate signal held high for the entire duration of the attack stage.902
CV Outputcv0V to 10VBipolar CV output carrying the envelope signal (0–10 V during envelope generation) or slewed throughput voltage (−10 to +10 V in CV-through mode).902
Combined Trigger Outputtrigger≤10VFires a 10 V trigger pulse at the start of each envelope stage transition.902
Decay Gate Outputgate≤10VOutputs a 10 V gate signal held high for the entire duration of the decay stage.902
Release Gate Outputgate≤10VOutputs a 10 V gate signal held high for the entire duration of the release stage.902
Sustain Gate Outputgate≤10VOutputs a 10 V gate signal held high for the entire duration of the sustain stage.902

Parameters 7

NameTypeRangeBehavior
Attack Sliderfader0.003s – 10sSets the attack stage duration; moving upward increases attack time. With negative CV at the Attack CV Input, the minimum time can be reduced to approximately 0.8 ms.902
Decay Sliderfader0.003s – 12sSets the decay stage duration — the time to fall from peak to sustain level. Moving upward increases duration; with negative CV the minimum reduces to approximately 0.8 ms. In Hold Mode, defines slew time for descending voltages.902
Gate/Trig ButtonbuttonManually triggers the envelope when pressed; the LED illuminates proportionally to the output CV amplitude, providing visual feedback of envelope level.902
Gate/Trig ToggleswitchThree-position toggle selecting Gate Mode, Trig Mode, or Hold Mode, which determines how the module responds to incoming gate and trigger signals.902
Release Sliderfader0.003s – 12sSets the release stage duration — the time for the envelope to decay from the sustain level to 0 V after the gate signal drops low.902
Shape KnobknobSmoothly morphs envelope contour from fully linear (fully anticlockwise) to logarithmic attack with exponential decay and release (fully clockwise), as in classic East Coast ADSR circuits.902
Sustain Sliderfader0V – 10VSets the sustained voltage level held after the decay stage completes. In Hold Mode, adds a positive DC offset to the slewed input signal.902

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [902]
    Instruō cèis[2] User Manualmanual
    verified 2026-05-24
  2. [903]
    Instruō cèis[2] product pageproduct_page
    verified 2026-05-24