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-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-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-138f Dual 3-Way Crossfader

The A-138f is a small, dual, three-way crossfader. “Three-way” here means that we have three possible input signals and one output signal. You will look in vain for the extremely sophisticated options of the A-138e, which unfortunately is no longer manufactured. The A-138f simply fades between two signals “A” and “B” and then (from the … Read more

A-149-4 Quad Random Voltage Source

The A-149-4 module is now the third member of the “A-149 family”. All three modules are about generating random voltages or trigger signals that go well beyond the possibilities of the random/noise modules A-118-1, A-118-2 or A-117. The A-149-1, which is based on the Buchla module 266, already has quantized voltages available that can be … Read more

A-101-6 Opto FET Filter/Phaser

The Opto FET filter uses optical field effect transistors. That’s a statement you have to let sink in first. Maybe meditate on it too, it certainly won’t do any harm. Until then, very quietly, the question arises as to what on earth an optical field effect transistor could be and why you need something like … Read more

A-123-2 6/12/18/24 dB Highpass

After the Curtis chip CEM3320 was no longer available, Doepfer had to stop production of the A-123 24 dB highpass filter. It’s a pity, because there were simply no other 24 dB high-pass filters on the market! In the meantime, however, a replica is available with the AS3320, so that there is now a 24 … Read more