A-121s Stereo Multimode VCF

Does this sound familiar? A new module enters the market and your first thought is: Oh, I know that one, I already have one of these, two in one housing – so what… I’ll take another look anyway: Oh, morphing between filter types, even via CV. Lots of control inputs, common for both filters, separate … Read more

A-171-4 Quad VC Slew Limiter

The A-171-4 Quad Slew Limiter is the youngest member of Doepfer’s family of polyphonic modules. What they all have in common is a four-fold layout of the functionality. All of these are influenced by common controllers and/or common control voltages. In addition, all Poly modules (at least in current production) have the option of internal … Read more

A-129 / 5 Voiced/Unvoiced Detector

The module is no longer in production. The principle of the vocoder has problems with unvoiced modulator signals: For example, the hissing and explosive sounds when speaking (s, sh, t, p, etc.). If they are processed like vowels, the speech intelligibility of the result is usually not particularly high. That’s why vocoders often have modules … Read more

A-129 / 1 Vocoder Analysis & A-129 / 2 Vocoder Synthesis Section

The vocoder modules are no longer manufactured. The Doepfer vocoder consists – sorry, consisted – of several modules. The two basic modules A-129/1 (analysis unit) and A-129/2 (synthesis unit or filter) were only available together. In the A-129 / 1 Analysis Section, the audio input signal is routed in parallel through 13 (steep) bandpass filters, … Read more

A-121 Multimode Filter

The module is no longer in production. The A-121 is an early but very neat filter design by Doepfer. Unfortunately, the Curtis module CEM 3320 used is no longer available, so the module is no longer commercially available. It’s a shame because it has a very unique sound character and some interesting technical features. From … Read more

A-111-6 Miniature Synthesizer Voice

I often used my A-111-5 as a “stopgap” when I quickly needed another simple synthesizer voice and maybe was just too lazy to patch extra VCO, VCF, VCA, ADSR and LFOs for such a secondary voice . I was often plagued by the “guilty conscience of the modularist” when I ignored the far-reaching possibilities of … Read more

A-107 Multitype Morphing Filter

The module is no longer in production. The A-107 was basically an Xpander filter (A-106-6) with greatly expanded filter modes (36 instead of “only” 16) and a digital control for morphing between different filter modes. The filter itself is of course purely analog. The A-107 works with “filter chains”: Such a chain consists of a … Read more