Doepfer — A-140
Doepfer A-140 ADSR Manual (PDF)
Doepfer A-140 ADSR Cheat Sheet
The Doepfer A-140 ADSR is a classic envelope generator for the Eurorack modular system. It outputs a voltage envelope shaped by Attack, Decay, Sustain, and Release (ADSR) stages, and is a modulation source for VCAs, VCFs, VCOs, and more.
Quick Operation
- Connect a Gate (from sequencer, keyboard, LFO, etc.) to the Gate ( ! ) input or use internal INT.GATE.
- Set A, D, S, R knobs to your desired envelope shape.
- Patch Output ( § or $ ) to the destination to modulate (VCA, VCF, etc.).
- (Optional) Use Retrig ( " ) to re-trigger the envelope while the gate is high (great with LFOs/clocks).
- Select envelope time range (H, M, L) with the 3-way switch.
Panel Control Reference
| # |
Control/Input |
Type |
Description |
Range / Details |
| 1 |
A (Attack) |
Knob |
Sets the attack time |
0~10; ms to minutes (L-H range) |
| 2 |
D (Decay) |
Knob |
Sets the decay time |
0~10; ms to minutes (L-H range) |
| 3 |
S (Sustain) |
Knob |
Sets the sustain level (hold voltage) |
0~10; 0V to max (approx. +8V) |
| 4 |
R (Release) |
Knob |
Sets the release time |
0~10; ms to minutes (L-H range) |
| 5 |
ADSR Control |
LED |
Visual indicator of envelope activity |
- |
| 6 |
Time Range |
3-way Switch |
Sets overall envelope time scale |
H (hours), M (mid), L (<100 µs) |
Inputs & Outputs
| Symbol |
Jack Name |
Type |
Description |
Typical Range |
| ! |
Gate |
Input |
Starts envelope on rising edge |
Threshold: +0.8V / > 2V |
| " |
Retrig |
Input |
Retriggers attack while gate is high |
>+2V pulse recommended |
| §, $ |
Output |
Output |
Normal (positive) envelope voltage |
0V (rest) to +8V typ, up to +12V |
| % |
Inverse Output |
Output |
Inverted envelope voltage |
0V (rest) to -8V typ |
Each output simultaneously provides the same envelope. Both outputs ( §, $ ) are available for patch flexibility.
Voltage Ranges
- Envelope Out/Inverted Out:
- Normal: 0V (rest) up to approx. +8V (max, up to +12V)
- Inverse: 0V (rest) down to approx. -8V (min)
- Gate/Trig Inputs:
- Triggered at +0.8V ("gate on" >+2V safe)
- Retrig: >+2V pulse recommended
User Examples
- ADSR → VCA: Volume envelope for dynamic articulation.
- ADSR → VCF: Moving filter envelope for sweeps.
- ADSR → VCO PWM: Modulates pulse width, giving timbral movement.
- ADSR → VCO Pitch: Creates pitch swoops/attack transient effects.
- ADSR → Effects (Phase, LFO freq): Modulates FX or LFO for evolving patches.
Patch Notes
- Gate input is normalled to INT.GATE (from system bus/keyboard) unless a cable is inserted.
- Retrig re-triggers attack phase on each pulse received, while gate is high.
- Use the three time ranges to fit applications from percussive plucks (L), standard synth envelopes (M), to very slow pads (H).
- Inverse output can be used for complementary modulation.
Reference: Doepfer A-140 ADSR Manual (PDF)
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