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

A-129/1

Doepfer

Vocoder analyzer section. Splits a speech/voice signal through a bank of 13 bandpass filters plus 1 lowpass and 1 highpass filter, with an envelope follower per band producing 15 CV outputs that track the spectral envelope of the input signal.367

Capabilities 3

Bandpass Filterbandpass-filter
367
Envelope Followerenvelope-follower
Each of the 15 filter bands (1 lowpass, 13 bandpass, 1 highpass) has a dedicated envelope follower whose output voltage is available on a separate CV output jack with an LED indicator.367
Vocodervocoder
A-129/1 is the analysis section of a modular vocoder; it extracts the spectral envelope of a speech signal via 15 filter-envelope-follower pairs and outputs 15 CVs.367

Jacks 17 — 1 in / 16 out

NameSignalVoltageDescription
Inputs (1)
Speech InaudioInput for the speech/voice signal to be analyzed. Must be at A-100 internal signal level; use an A-119 External Input module for microphone signals.367
Outputs (16)
Band 1 (100 Hz LP) Env OutcvEnvelope follower CV output for band 1 (100 Hz lowpass). Tracks per-band amplitude of the analyzed speech signal. Front-panel control LED indicates current level.367
Band 10 (1.6 kHz) Env OutcvEnvelope follower CV output for band 10 (1.6 kHz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 11 (2.3 kHz) Env OutcvEnvelope follower CV output for band 11 (2.3 kHz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 12 (3.3 kHz) Env OutcvEnvelope follower CV output for band 12 (3.3 kHz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 13 (5 kHz) Env OutcvEnvelope follower CV output for band 13 (5 kHz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 14 (7.5 kHz) Env OutcvEnvelope follower CV output for band 14 (7.5 kHz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 15 (10 kHz HP) Env OutcvEnvelope follower CV output for band 15 (10 kHz highpass). Tracks per-band amplitude of the analyzed speech signal. Front-panel control LED indicates current level.367
Band 2 (120 Hz) Env OutcvEnvelope follower CV output for band 2 (120 Hz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 3 (160 Hz) Env OutcvEnvelope follower CV output for band 3 (160 Hz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 4 (230 Hz) Env OutcvEnvelope follower CV output for band 4 (230 Hz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 5 (330 Hz) Env OutcvEnvelope follower CV output for band 5 (330 Hz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 6 (500 Hz) Env OutcvEnvelope follower CV output for band 6 (500 Hz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 7 (750 Hz) Env OutcvEnvelope follower CV output for band 7 (750 Hz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 8 (1.1 kHz) Env OutcvEnvelope follower CV output for band 8 (1.1 kHz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
Band 9 (1.3 kHz) Env OutcvEnvelope follower CV output for band 9 (1.3 kHz bandpass). Tracks per-band amplitude of the analyzed speech signal.367
High Pass OutputaudioAudio output of the 10 kHz high pass filter stage. Carries the high-frequency content of the speech signal; typically mixed into the vocoder output to improve speech intelligibility.367

Parameters 0

No parameters recorded.

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [367]
    Doepfer A-129/1 + A-129/2 Vocoder Analyzer/Synthesizer Manualmanual
    verified 2026-05-15
  2. [368]
    Doepfer A-129 Vocoder Subsystem product pageproduct_page
    verified 2026-05-15