Eurorack Reference / modules /doepfer/a-126-2 audit site v0.1 — milestone 3
doepfer/a-126-2

A-126-2

Doepfer

Capabilities 1

Frequency Shifterfrequency-shifter
363

Jacks 9 — 6 in / 3 out

NameSignalVoltageDescription
Inputs (6)
Audio InaudioAudio input with attenuator (Level knob). Typical input level 1Vpp. Adjust Level so overload LED just begins to light; full LED = clipping, permanently off = level too low.363
Cos (input)audioExternal cosine input for an external quadrature VCO. Normalled to the internal quadrature VCO. Expected level ~10Vpp (8–10Vpp OK), must be zero-symmetrical.363
FCV IncvCV input with attenuator for external voltage control of the shifting frequency.363
Mix CV IncvCV input with attenuator for external voltage control of the up/down shift mixing ratio.363
Sin (input)audioExternal sine input for an external quadrature VCO. Normalled to the internal quadrature VCO. Expected level ~10Vpp (8–10Vpp OK), must be zero-symmetrical.363
VCA ext. CVcvExternal CV input to control the output VCA, bypassing the internal squelch. Normalled to squelch control signal. From about +8V the VCA is fully open.363
Outputs (3)
Audio OutaudioAudio output of the frequency shifter; output of the up/down mixing unit.363
Cos (output)audio-6V to 6VCosine output of the internal quadrature VCO, approximately 12Vpp (+6V/-6V).363
Sin (output)audio-6V to 6VSine output of the internal quadrature VCO, approximately 12Vpp (+6V/-6V).363

Parameters 7

NameTypeRangeBehavior
FCVknobAttenuator for the FCV In jack; controls the amount of external CV applied to the shifting frequency.363
Frequ. 1knob20Hz – 5000HzFirst manual control of the shifting frequency. Factory default is coarse setting (about 20Hz–5kHz). Can be swapped to fine via internal jumper JP15.363
Frequ. 2knobSecond manual control of the shifting frequency. Factory default is fine setting. The coarse-to-fine ratio is about 25:1 (approx. 8 octaves to 1/3 octave). Can be swapped to coarse via internal jumper JP16.363
LevelknobAttenuator for the audio input. Adjust so overload LED just begins to light; full LED = clipping/distortion, permanently off = level too low (degrades SNR). Typical input level 1Vpp.363
MixknobControls the ratio of up-shift to down-shift signal at the audio output. Fully CCW = down shift only; fully CW = up shift only; in between = blend of both.363
Mix CVknobAttenuator for the Mix CV In jack; controls the amount of external CV applied to the up/down mixing ratio.363
SquelchknobControls squelch function. Fully CCW: output VCA follows the envelope derived from the audio input (mutes when no signal). Fully CW: VCA permanently open, squelch disabled. In between: continuously adjustable squelch intensity.363

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [363]
    Doepfer A-126-2 Voltage Controlled Frequency Shifter II Manualmanual
    verified 2026-05-15
  2. [364]
    Doepfer A-126-2 product pageproduct_page
    verified 2026-05-15