doepfer-a-140-1

Doepfer A-140-1 ADSR

Four-stage envelope generator with retrigger and inverse output

8 HP Eurorack module

The A-140 ADSR is a classic four-stage envelope generator that outputs a time-varying control voltage with Attack, Decay, Sustain, and Release stages. It is a fundamental modulation source in a modular system, capable of shaping loudness, filter brightness, pitch, timbre, and phase over the duration of a note, with both normal and inverted outputs for expressive bipolar modulation.

Features

  • Four-stage ADSR envelope generator
  • Attack, Decay, Sustain, Release controls with range 0-10
  • Three-position Time Range switch: High (up to minutes), Medium (standard), Low (less than 100 microseconds)
  • Normal output reaches approximately +8V peak
  • Inverted output with negative voltages (approximately -8V peak)
  • Two identical normal outputs (Output 3 and Output 4)
  • Retrigger input for re-starting envelope from scratch while gate is still open
  • Gate input normalled to INT.GATE system bus
  • Normalling can be permanently removed via jumper on circuit board
  • ADSR Control LED provides visual indication of envelope voltage at output
  • Can be triggered by internal gate, MIDI/CV interface note-on, or external gate signal
  • Envelope suitable for modulating VCO, VCF, VCA, VCP, VCLFO, and other modules

Controls & Jacks (11)

  • Release— Sets the release time, controlling how fast the output falls to zero after the gate closes.
  • Decay— Sets the decay time, controlling how fast the output falls from peak to the sustain level.
  • Sustain— Sets the sustain level, the steady-state voltage after decay phase while the gate remains open.
  • Attack— Sets how long the envelope takes to rise from zero to its maximum voltage (~8V) after a gate signal is received.
  • Output 2— Secondary envelope output, identical to the main output.
  • Output— Main envelope output carrying the control voltage shaped by Attack, Decay, Sustain, and Release parameters.
  • Inverse Output— Inverted envelope output carrying the negative of the envelope voltage.
  • Time Range— Three-position rotary switch selecting the time range: H (high, up to minutes), M (medium, standard mid-range), or L (low, down to less than
  • Retrig— Re-trigger input; allows the envelope to restart each time a pulse is received while the gate is open.
  • ADSR Control— LED that gives a visual indication of the envelope voltage currently being output. Brightness reflects the current envelope level.
  • Gate— Input jack that receives a gate voltage to trigger the envelope. When voltage is present, the ADSR starts its attack phase; when voltage dro

How-To Guides

  • Classic Amplitude Envelope
  • Dynamic Filter Brightness
  • Percussive Pluck Envelope
  • Slow Pad Swell
  • LFO Retrigger Tremolo
  • Inverse Envelope Ducking
  • Pitch Envelope for Tonal Punch
  • Envelope-Controlled Pulse Width Timbre
  • Envelope-Modulated LFO Speed
  • Dual Destination Layered Envelope

Explore the interactive A-140-1 ADSR panel on BleepDex — tap any control to learn what it does.

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