Doepfer A-132-3 Dual Low Cost VCA
Two linear VCAs for CV and audio level control
8 HP Eurorack module
The Doepfer A-132-3 is a dual voltage controlled amplifier with switchable linear/exponential response. Each VCA features a manual gain control, two summing CV inputs, and DC-coupled signal path suitable for both audio and control voltages. The linear/exponential switch allows each VCA to be optimized for its task: linear mode preserves CV waveform shapes for modulation routing, while exponential mode provides musically natural volume curves for audio. The module has been manufactured with two different ICs over its history: the CEM/AS3360 (which hard-limits gain to unity) and the SSM2164 (which allows gain beyond unity, potentially causing clipping). Input handles up to 16Vpp without distortion. Width: 8HP, current: +30mA/−30mA.
Features
- Two independent voltage controlled amplifiers in one module
- Linear response curve ideal for control voltage level management
- Two CV inputs per VCA whose voltages are summed to determine amplification
- 0V CV input yields zero amplification; 5V CV input yields maximum amplification
- Can be used for audio signal amplitude control in non-critical applications
- Suitable for controlling ADSR amount, vibrato level, and modulation depth
- Can be driven by MIDI-CV velocity output to scale envelope or modulation amount
- Compact dual-channel format with four jacks per channel
Controls & Jacks (20)
- CV 2
- CV 1
- Gain 2
- Gain
- VCA 2 Signal In 1 — Amplified signal output from VCA 1
- VCA 2 CV 1 — Signal input for VCA 1
- VCA 2 CV 2 — Control voltage input 1 for VCA 1
- VCA 2 Signal Out 1 — Control voltage input 2 for VCA 1
- VCA 2 Signal In 2 — Signal input for VCA 2
- VCA 2 Signal Out 2 — Amplified signal output from VCA 2
- Lin 2
- Lin 1
- CV 1 (VCA 1) — Control voltage input 1 for VCA 1
- CV 2 (VCA 1) — Control voltage input 2 for VCA 1
- Sig. In (VCA 1) — Signal input for VCA 1
- Sig. Out (VCA 1) — Amplified signal output from VCA 1
- CV 1 (VCA 2) — Control voltage input 1 for VCA 2
- CV 2 (VCA 2) — Control voltage input 2 for VCA 2
- Sig. In (VCA 2) — Signal input for VCA 2
- Sig. Out (VCA 2) — Amplified signal output from VCA 2
How-To Guides
- Basic CV Level Control
- Velocity-Controlled Envelope Depth
- Voltage-Controlled Vibrato Depth
- AM with Voltage-Controlled Modulation Amount
- Voltage-Controlled Noise Level
- Dual Parallel CV Scaling
- Summed CV Crossfading
- Gate-Controlled CV On/Off
Explore the interactive A-132-3 Dual Low Cost VCA panel on BleepDex — tap any control to learn what it does.
