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Doepfer 1

The Five-way VC slew limiter / offset generator / attenuators (A-129 /3) and Slew controllers (A-129/4) are
particularly designed for this purpose. Module A-129 /3 includes 5-way Attenuators, 5-way Offset Generators,
and a Slew Limiter (which works on all the voltages at the five CV inputs simultaneously). Using the A-129 /3
just on its own, two functions are available:
  • Attenuator: whatever signal is patched into the CV input can be attenuated by your chosen amount

  • before being sent to the CV output. The attenuation is set with a control knob.

  • Offset Generator: whatever signal is patched into the CV input will have an offset voltage added to it

  • before being sent to the output. The offset is variable with a control knob.

The Slew Limiter function is only available if the Slew Control Input of the module A-129/3 is controlled by

the Slew Limiter Controller A-129/4 (see below).

For the maximum extension of the vocoder three modules A-129/3 are required as the A-129/3 contains only

5 units but the complete vocoder has 15 frequency bands. Usually, the A-129/3 is patched between the CV

outputs of the analysis section A-129/1 and the CV inputs of the synthesis section A-129/2. You can also

use module A-129 /3, particularly in combination with A-129/4, for other purposes. For example, using the

A-129/2 synthesis section only, you can make a filterbank.

Module A-129/3 can also be used out of a vocoder to attenuate any signal in the A-100 and to add a fixed

offset voltage (e.g. to expand the features of the dual low cost VCA A-132, the Quantizer A-156 or the

Sampler A-112). 

Module A-129/3 is suitable only for the processing of control voltage signals. It cannot be used to process

audio signals.

For more detailed information please look at the English user's manual of A-129/3 and /4: A1293man.pdf

A special MIDI-interface for the vocoder system is planned. The basic functions are a 16-way CV-to-MIDI interface and a 16-way MIDI-to-CV interface (way 16 will be used for other functions like controlling slew-rate or voiced/unvoiced). The CV-to-MIDI section converts the CV outputs of vocoder analysis into MIDI controllers which may be recorded by a computer sequencer. The MIDI-to-CV section converts incoming MIDI controller information into CV's for the vocoder synthesis section. Additionally we plan to store some factory and user definable 'vocals' in the MIDI interface so that you may call up complete vocals (like 'a', 'e', 'o', 's', 'sh' and so on) by MIDI program change events (may be we use another MIDI event type for this purpose). Thus the vocoder system will become a universal MIDI controlled filter system not limited to the standard vocoder features.

A suggestion for a complete vocoder systems is described in the A-100 System Examples. Other system combinations be planned  with the A100 planner (MS Excel required).

Overview: Prices / Width / Depth / Current of all A-129-x modules:


Price [Euro]
with red LEDs

Price [Euro]
with blue LEDs

Width [HP / mm]

Depth [mm]

Current [mA]




20 + 12 HP = 32 HP / 101.3 + 60.6 mm

60 mm

180 mA


(has no LEDs)

(has no LEDs)

16 HP / 80.9 mm

60 mm

40 mA




8 HP / 40.3 mm

40 mm

30 mA




8 HP / 40.3 mm

45 mm

30 mA

The price in US$ depends upon the exchange rate between Euro and US$ at the payment day. Free currency converter:
All specifications and prices are subject to change.

A-129/1 und /2 are available only together. 
The additional price for each blue LED is Euro 2.00.
The maximum extension of the vocoder requires these modules: 1xA-129/1+2, 3xA-129/3, 1xA-129/4 und 1xA-129/5.