Doepfer A-130-2 Dual VCA

Dual-mode VCA for audio shaping and CV control

4 HP Eurorack module

The A-130/A-131 are voltage-controlled amplifiers that provide voltage-controlled amplification of audio or CV signals. The A-130 uses a linear response curve while the A-131 uses an exponential (logarithmic) response, making the A-130 ideal for CV processing and the A-131 ideal for natural-sounding audio amplitude control.

Features

• Linear response curve (A-130) or exponential/logarithmic response curve (A-131)
• Two audio inputs each with individual attenuator knobs
• Two CV inputs: CV 1 (direct) and CV 2 (with attenuator)
• Gain knob sets overall amplification offset, shifting entire VCA response curve upward
• Output attenuator for total volume control of combined audio output
• Effective CV range: 0V (no amplification) to +5V (maximum amplification)
• CV 1 and CV 2 voltages are combined to determine amplification
• Suitable for audio signals (A-131) or control voltage processing (A-130)
• Can produce tremolo when modulated by LFO in sub-audio range (1 Hz to 15 Hz)
• Supports keyboard tracking via CV input from keyboard controller
• Supports inverted keyboard tracking via Voltage-Inverter A-175
• Patch sheet included for documenting user patches

Controls & Jacks (16)

• VCA 1 CV 2— CV attenuator for VCA 1 CV 2 input, controls the amount of effect the CV has on amplification
• VCA 1 Audio In 1— Audio input attenuator for VCA 1 input 1
• VCA 1 Audio In 1— First audio input for VCA 1
• VCA 1 Gain— Overall gain control for VCA 1, determining amplification amount from 0 (no amplification) to maximum
• VCA 1 CV 1 1— Second control voltage input for VCA 1 with attenuation
• VCA 1 Audio Out— Audio output from VCA 1
• VCA 2 Gain— Overall gain control for VCA 2, determining amplification amount from 0 (no amplification) to maximum
• VCA 1 CV 1 2— Control voltage input for VCA 1
• VCA 1 Audio In 2— Second audio input for VCA 1
• VCA 2 CV 1— Control voltage input for VCA 2
• VCA 1 Out— Output level control for VCA 1, attenuates the combined amplified signal
• VCA 2 CV 2— CV attenuator for VCA 2 CV 2 input, controls the amount of effect the CV has on amplification for VCA 2
• VCA 2 Audio In 1— Audio input attenuator for VCA 2 input 1
• VCA 2 Audio In 2— Audio input attenuator for VCA 2 input 2
• VCA 2 Out— Output level attenuator for VCA 2
• VCA 2 Audio Out— Audio output from VCA 2

How-To Guides

• Classic ADSR Amplitude Shaping
• Tremolo via LFO Amplitude Modulation
• Keyboard Tracking — Louder with Higher Notes
• Inverted Keyboard Tracking — Louder with Lower Notes
• Noise Burst Percussion Shaping
• CV Signal Gating and Scaling
• Two-Source Audio Mixing Through Single VCA
• AM Synthesis with Audio-Rate LFO
• Voltage-Controlled Tremolo Depth

Explore the interactive A-130-2 Dual VCA panel on BleepDex — tap any control to learn what it does.