A-160-2 Clock/Trigger Divider II

The A-160-2 actually does exactly what I always wanted from a clock divider. It splits an incoming clock signal in a “musical” way. What does that mean? A simple clock divider like the old A-160-1 counts the input triggers, so to speak, and always divides them into two equal halves, depending on the division factor. … Read more

A-152 Voltage Addressed Track&Hold / Switch

The A-152 Voltage Addressed Track & Hold / Switch module is by far the most flexible switching module presented here. It offers a bidirectional 8:1 or 1:8 switch that can be addressed via control voltage as well as switched sequentially via trigger signals (or switched back to the first level with a reset trigger). In … Read more

A-101-2 Vactrol Lowpass Gate

A Lowpass Gate (LPG) is an odd device. It uses a vactrol circuit and couples a low pass filter to an amplifier (VCA). Then why not just use a filter and an amplifier separately? The LPG can be switched between VCF, VCA and the combination VCF / VCA! In addition, the module is built with … Read more

A-133-2 Dual VC Polarizer

The A-133-2 is a dual voltage controlled polarizer, meaning its input signals (audio or control voltages) can be amplified like a traditional VCA. With a negative control voltage or a corresponding manual setting, the input signals are amplified in inverted form. An input, a control voltage input, an output, as well as a manual controller … Read more

A-143-4 Quad VCLFO/VCO

The Quad VCLFO is actually almost a “real” VCO: It even has temperature compensation, which allows it to remain in tune even with external temperature fluctuations. Doepfer points out that the A-143-4 is not quite as accurate as the VCOs of the A-110 or A-111 series, but from my point of view it can be … Read more

A-141-4 Quad Poly VCADSR

The A-141-4 is a quadruple ADSR that is only 8 TE wide and is primarily intended for polyphonic applications. Therefore, there is only one set of controls for the envelope’s parameters – attack, decay, sustain and release, which affect all four envelopes equally. In addition, we find four control voltage inputs with bipolar attenuators for … Read more

A-105-4 Quad Poly SSI VCF

The A-105-4 is a polyphonic filter module based on the SSM2024 integrated circuit (or its replica SSI2144). In principle, we have four A-105 filters with a common control in front of us: Cutoff frequency, resonance (called “Q” here) and input level can be set in the same way for all four filters or also controlled … Read more

A-111-4 Quad Precision VCO

The family of A-111 oscillators now includes an impressive 6 variants, all of which use the Curtis chip CEM3340 (or replica) with its triangular core and allow very precise tracking over 10 octaves and more. The A-111-4 is – nomen est omen – designed fourfold and also has a common “master” section, which affects all … Read more