A-190-5 Polyphonic USB/Midi-to-CV/Gate Interface

The A-190-5 is a Midi-to-CV/Gate interface primarily intended for polyphonic applications. This means that up to four modular synthesizer voices can be controlled via any midi keyboard. Polyphony is still a rather exotic “fringe phenomenon” in the modular area. Effort, cost and complexity to control such a system appear relatively high compared to modern analog … Read more

A-121-2 12 dB Multimode Filter

Like its predecessor A-121, the A-121-2 filter is a multimode filter with 12dB slope that offers separate outputs for highpass, lowpass, bandpass and notch (bandstop). Technically, the filter is a direct offshoot of the “Dark Energy II” synthesizer, which basically uses the same circuitry. How does it sound? Fine, round, pleasant and in terms of … Read more

A-120 24dB Low Pass Filter

The A-120 module is – the name “Low Pass 1” suggests it – something like the “mother of all Doepfer filters” (from a historical perspective, not from a technical perspective). The circuit is based on the famous 24 dB Moog transistor cascade (“ladder” filter). And this is actually the official mother of all synthesizer filters. … Read more

A-111-5 Mini Synthesizer Voice

The A-111-5 is not an oscillator in the traditional sense, but a complete mini synthesizer with VCO, VCF, VCA, ADSR and two LFOs. A “Dark Energy” (first generation) for the modular system! A lot of things here are patchable, but upon closer inspection you’ll see that some signal paths are exclusively internal. For example, there … Read more

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-111-3 Micro Precision VCO / VCLFO

An almost ideal VCO for small, portable module systems: The A-111-3 measures just 4 TE! At its core, it is the same VCO as the A-111-2 High End VCO II, which, however, is much more luxuriously equipped. So, again, we’re dealing with a highly tuning stable oscillator that offers pretty perfect tracking of 1V/octave over … 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-118-2 Noise / Random / T&H / S&H

The “Slim Line” module is a version of the classic analogue noise generator A-118-1 reduced to half the width (only 4HP). As with the other “Slim Line” modules, slightly smaller buttons and sockets with narrow, round nuts are also used here. The controls are at the top and the sockets are at the bottom, which … Read more

A-115 Audio Divider

The A-115 audio divider is a simple frequency divider that outputs square wave signals of 1/2, 1/4, 1/8 and 1/16 the frequency of the input signal. This corresponds to a tone 1, 2, 3 and 4 octaves below the input signal. User interface Inputs: Outputs: Controls: Suboscillator The A-115 Audio Divider can be used very … Read more