A-140

Doepfer 8HP
ENVELOPE FUNCTION UTILITY

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Classic ADSR envelope generator. Gate input triggers envelope; Retrig re-opens attack while gate held. Two identical positive outputs (~0 to +8V) plus an inverted output (~0 to -8V). 3-position time range switch spans <100µs to minutes.

Patch Ideas · 5

★ Classic voice envelope
Gate → Gate · Output → VCA CV · Inverse Output → VCF CV for sweep-down
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: A-140, Keyboard, VCA, VCF. Signals: 2 cv, 1 gate.A-140KeyboardVCAVCFA: fast · D: med · S: 6 · R: med · Time Range: MGategateOutputcvInverse OutputcvGategateCVcvCVcv11. filter closes as envelope openscvgate
Retrig-driven tremolo envelope
LFO square → Retrig repeats A/D bursts while key held · Output → VCA
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: A-140, Keyboard, LFO, VCA. Signals: 1 cv, 1 gate, 1 trigger.A-140KeyboardLFOVCAA: fast · D: slow · S: 0 · R: med · Time Range: LGategateRetrigtrigOutputcvGategateSqrtrigCVcv11. percussive bursts inside each notecvgatetrigger
Dual destination from twin outputs
Both positive outputs drive independent targets without a mult — one to VCA, one to pitch FM
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: A-140, Gate Source, VCA, VCO. Signals: 2 cv, 1 gate.A-140Gate SourceVCAVCOA: slow · D: med · S: 4 · R: slowGategateOutputcvGategateCVcvExp FMcv11. small pitch rise on attackcvgate
★ Ducking sidechain
Drum gate → Gate · Inverse Output → VCA CV on pad voice for rhythmic duck
▸ Show diagram
Patch diagramPatch diagram with 4 modules and 3 connections. Modules: A-140, Drum, Pad Voice, VCA. Signals: 1 audio, 1 cv, 1 gate.A-140DrumPad VoiceVCAA: very fast · D: med · S: 0 · R: medGategateInverse OutputcvGategateAudioaudioInaudioCVcv11. VCA dips on each hitaudiocvgate
★ Slow drone morph
Time Range H for minute-long sweeps · Output → filter cutoff for slowly evolving timbre
▸ Show diagram
Patch diagramPatch diagram with 3 modules and 2 connections. Modules: A-140, Manual Gate, VCF. Signals: 1 cv, 1 gate.A-140Manual GateVCFA: 10 · D: 10 · S: 5 · R: 10 · Time Range: HGategateOutputcvGategateCutoffcv11. multi-minute openingcvgate

Behaviors

Standard ADSR shape gate high

On gate rising edge, output rises to peak over A time, falls to S level over D time, holds at S until gate off, then falls to 0V over R time.

Gate-length release short gate during A or D

If gate falls before sustain is reached, envelope begins R from the current voltage level, producing shortened percussive shapes.

Re-triggering pulse → Retrig while gate high

Each Retrig pulse restarts A→D from current envelope value without requiring gate to cycle. Driving Retrig from an LFO produces repeating envelopes locked to the gate duration.

System bus gate normalling no cable in Gate

Gate jack is normalled to the A-100 system bus INT.GATE line, so MIDI-CV or keyboard gates reach all A-140 modules without patching. Insert a cable to break the bus normal.

Bipolar modulation from Inverse Out Output + Inverse Output summed

Inverse Output carries the same shape mirrored to negative voltages, useful for simultaneous opening/closing of paired VCAs or crossfader duck patches.

Controls

Envelope A Attack time — rise from 0V to peak (~+8V) after gate on.
L: sub-ms · M: standard · H: up to minutes (set by Time Range)
Envelope D Decay time — fall from peak to sustain level.
L: sub-ms · M: standard · H: up to minutes (set by Time Range)
Envelope S Sustain level — steady voltage held while gate remains high.
0 to ~+8V
Envelope R Release time — fall from sustain to 0V after gate off.
L: sub-ms · M: standard · H: up to minutes (set by Time Range)
Envelope Time Range 3-position range switch scales all four time stages (A, D, R).
L: <100µs–fast · M: standard mid-range · H: up to minutes
Indicator ADSR Control LED tracks envelope output voltage for visual feedback.
brightness ∝ output

I/O

IN · 2

  • Gate +3 to +12V GATE
    Gate input. Rising edge starts A→D→S phase; falling edge starts R phase.
    NORM → A-100 bus INT.GATE line (disable via internal red jumper)
  • Retrig trigger/gate GATE
    Re-trigger input. Pulse restarts envelope from current level while Gate is still high.

OUT · 3

  • Output ~0 to +8V ENV
    Positive envelope output.
  • Output ~0 to +8V ENV
    Second identical positive envelope output (hard-wired copy, no buffer).
  • Inverse Output ~0 to -8V ENV
    Inverted envelope — mirrored around 0V.