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.
