Eurorack Reference / modules /doepfer/a-129-2 audit site v0.1 — milestone 3
doepfer/a-129-2

A-129/2

Doepfer

Synthesis section of the A-129 modular vocoder. Takes a carrier signal through a bank of 15 bandpass/lowpass/highpass filters, each with a VCA controlled by CV inputs from the A-129/1 analysis section, producing the classic vocoder effect. Can also be used as a standalone voltage-controlled filter bank.369

Capabilities 3

Fixed Filter Bankfixed-filter-bank
15 filters: 1 lowpass (100 Hz), 13 bandpass (120 Hz–7.5 kHz), 1 highpass (10 kHz). Can be used standalone as a voltage-controlled filter bank.369
VCA Bankvca-bank
Each of the 15 filter bands has a dedicated VCA whose gain is controlled by the corresponding CV input, allowing per-band amplitude modulation from the analysis section.369
Vocodervocoder
Synthesis section of the A-129 modular vocoder. Carrier signal is split into 15 filter bands (13 bandpass + lowpass + highpass); each band's VCA is driven by a corresponding CV input from the A-129/1 analysis section.369

Jacks 17 — 16 in / 1 out

NameSignalVoltageDescription
Inputs (16)
Band 1 (100 Hz LP) CV IncvCV input controlling the VCA on band 1 (100 Hz lowpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 1 envelope-follower output.369
Band 10 (1.6 kHz) CV IncvCV input controlling the VCA on band 10 (1.6 kHz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 10 envelope-follower output.369
Band 11 (2.3 kHz) CV IncvCV input controlling the VCA on band 11 (2.3 kHz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 11 envelope-follower output.369
Band 12 (3.3 kHz) CV IncvCV input controlling the VCA on band 12 (3.3 kHz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 12 envelope-follower output.369
Band 13 (5 kHz) CV IncvCV input controlling the VCA on band 13 (5 kHz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 13 envelope-follower output.369
Band 14 (7.5 kHz) CV IncvCV input controlling the VCA on band 14 (7.5 kHz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 14 envelope-follower output.369
Band 15 (10 kHz HP) CV IncvCV input controlling the VCA on band 15 (10 kHz highpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 15 envelope-follower output.369
Band 2 (120 Hz) CV IncvCV input controlling the VCA on band 2 (120 Hz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 2 envelope-follower output.369
Band 3 (160 Hz) CV IncvCV input controlling the VCA on band 3 (160 Hz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 3 envelope-follower output.369
Band 4 (230 Hz) CV IncvCV input controlling the VCA on band 4 (230 Hz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 4 envelope-follower output.369
Band 5 (330 Hz) CV IncvCV input controlling the VCA on band 5 (330 Hz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 5 envelope-follower output.369
Band 6 (500 Hz) CV IncvCV input controlling the VCA on band 6 (500 Hz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 6 envelope-follower output.369
Band 7 (750 Hz) CV IncvCV input controlling the VCA on band 7 (750 Hz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 7 envelope-follower output.369
Band 8 (1.1 kHz) CV IncvCV input controlling the VCA on band 8 (1.1 kHz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 8 envelope-follower output.369
Band 9 (1.3 kHz) CV IncvCV input controlling the VCA on band 9 (1.3 kHz bandpass) of the synthesis filter bank. In the standard vocoder patch, fed from the A-129/1 Band 9 envelope-follower output.369
Instrument InaudioInput for the carrier signal (instrument). Accepts harmonically-rich audio such as sawtooth waves, noise, or multiple VCOs.369
Outputs (1)
Vocoder OutaudioAudio output for the entire vocoder synthesis section, mixing all filter band VCA outputs.369

Parameters 0

No parameters recorded.

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [369]
    Doepfer A-129/1 + A-129/2 Vocoder Analyzer/Synthesizer Manualmanual
    verified 2026-05-15
  2. [370]
    Doepfer A-129 Vocoder Subsystem product pageproduct_page
    verified 2026-05-15