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

A-116 VC Waveform Processor

“Processor” here does not mean a processor in a computer, but simply an (analog) circuit that can change waveforms. Here the input signal is processed by two parallel circuits, the results of which are then mixed together: a clipper, which cuts the input signal sharply above a threshold, and a polarizer/attenuator, which can both attenuate … Read more

A-114 Ring Modulator

From a mathematical point of view, a ring modulator forms the product of two signals and then subtracts the sum of the signals from it: a * b – (a + b) Unfortunately, this great formula does not make us any smarter in terms of sound. Actually, this is “only” amplitude modulation, which, in contrast … Read more

A-112 VC Sampler / Wavetable Osc.

The A-112 is a small digital module that can record, store and play back transposed audio material – a sampler in small format. In addition, the module can also be used for simple wavetable synthesis and as an effects device. The module has two small memory banks (each 64 kbytes in size) to store audio … Read more

A-189-1 Voltage Controlled Bit Modifier / Bit Cruncher

The Bit Modifier / Bit Cruncher is one of the digital modules that can be modulated with analog control voltages. The module is based on a 12-bit converter, which fits quite well for the intended “Lo-Fi” effects. Simply put, the module performs some purely mathematical operations after converting the audio signals into digital information and … Read more

A-144 Morphing Controller

The module is no longer in production. The A-144 Morphing Controller generates control voltages that are used, for example, to regulate four linear VCAs of a voltage-controlled mixer in such a way that the four input signals of the mixer are morphed one after the other. The A-135-1 or A-135-2 Voltage Controlled Mixer and the … Read more

A-113 Subharmonic Generator

The Subharmonic Oscillator is a very unusual module that originated in Doepfer’s Trautonium project. Doepfer had implemented the necessary components of a Trautonium (a historical forerunner of today’s analog synthesizer by Friedrich Trautwein, 1888-1956) within the A-100 system. Unlike most other frequency dividers that output square wave signals, the A-113 produces sawtooth signals whose frequency … Read more

A-126 Voltage Controlled Frequency Shifter

The module is no longer in production. Unfortunately, the VC Frequency Shifter is no longer available because one of the components used is no longer manufactured. In principle, however, the task of the missing component could be taken over by an A-143-9 Quadrature LFO or an A-110-4 Quadrature Thru Zero VCO, so that this particular … Read more

A-168-1 PWM Generator

The A-168-1 is a small auxiliary module that generates a square or pulse oscillation that can be modulated in width for LFOs or VCOs without a square/pulse. This is an interesting feature for LFOs in particular, since almost all LFOs can generate a fixed, symmetrical square wave (at least the A-146 is capable of manually … Read more

A-167 Analog Comparator / Subtractor / Offset Generator

The module is no longer in production. The A-167 Analog Comparator can compare voltages with each other and generate a gate signal. There are many possibilities: comparison of two external voltages, comparison of a voltage (normal or inverted) with a positive or negative threshold value, comparison of the difference between two external voltages with a … Read more