doepfer-a-135-2

Doepfer A-135-2 Quad VCA / VC Mixer

Four linear VCAs plus a VC mixer in 8 HP — DC coupled, jumper-configurable.

8 HP Eurorack module

Doepfer's A-135-2 packs four linear VCAs and a voltage-controlled mixer into 8 HP. Each VCA has a manual Level knob (L1–L4), a CV input with attenuator (CV1–CV4), a signal input, and an individual signal output. The four VCA outputs are summed internally to two mix jacks: Selected (only the VCAs whose individual outputs are unpatched) and All (always all four). Inputs and outputs are DC-coupled, so the module handles audio and control signals equally. Internal jumpers (JP4–JP10) rewire CV routing for stereo VCA, quad-VCA, and chain-normalled signal distribution modes.

Features

  • Four linear VCAs in 8 HP
  • DC-coupled audio + CV path
  • Per-channel manual Level knob plus CV input with attenuator
  • Per-channel individual signal output
  • Two mix outputs: Selected (unpatched channels only) and All (always all four)
  • Maximum mixer gain 0.6× to avoid clipping
  • Internal jumper-configurable CV routing (independent / stereo / quad-from-one-CV)
  • Optional jumper-normalled signal distribution chain (1 In → 2 In → 3 In → 4 In)
  • Skiff-friendly 45 mm depth
  • Small format makes it easy to dedicate one VCA per voice
  • Doepfer A-100 system standard build quality

Controls & Jacks (22)

  • L1
  • L2
  • L3
  • L4
  • CV1 Attenuator
  • CV2 Attenuator
  • CV4 Attenuator
  • CV3 Attenuator
  • 3 CV In
  • 1 CV In
  • 2 CV In
  • 4 CV In
  • 1 In
  • 2 In
  • 3 In
  • 4 In
  • 1 Out
  • 2 Out
  • 3 Out
  • 4 Out
  • Selected
  • All

How-To Guides

  • Quad VCA for four voices
  • Voltage-controlled four-channel mixer
  • One source → four levels (with internal JP8–JP10 jumpers)
  • Stereo VC amplifier (with JP7 jumper)
  • Compare Selected vs All mix taps

Explore the interactive A-135-2 Quad VCA / VC Mixer panel on BleepDex — tap any control to learn what it does.

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