A-117 Digital Noise / Random Clock / 808 Sound Source

The Digital Noise Generator A-117 creates random, short impulses. The frequency of these pulses can basically be controlled, namely via the “Rate” controller or alternatively via an externally applied clock. In contrast to an oscillator, the respective occurrence is “yes or no” as well as the length of such a pulse is random (technically “pseudo-random” … Read more

A-118-1 Noise + Random Volt.

Like the A-117 Digital Noise, the A-118-1 is a random noise generator. However, it does not work with feedback shift registers, but with the “natural” noise of transistors and thus generates a very typical “synthesizer” noise. Dieter Döpfer once explained to me that due to the component tolerances of these transistors, each A-118-1 sounds a … Read more

A-149-1 Quantized/Stored Random Voltages

The A-149-1 Quantized / Stored Random Voltages is a lavishly equipped random generator that is based on the Buchla modules 265 and 266. There are two different sub-modules: Quantized Random Voltages provides random voltages whose level is within a “grid”, a quantization. These are then distances of 1 V at output “n+1” and distances of … Read more

A-110-6 Trapezoid Quadrature Thru Zero VCO

Compared to the A-110-4 Quadrature Thru Zero VCO, the A-110-6 has one more thing on top: We are not dealing with a sine core, but with a trapezoid core. This is a unique design that first creates a trapezoidal waveform, as well as a 90 degree phase-shifted trapezoid (the equivalents of the A-110-4‘s sine and … Read more

A-188-1 BBD Module

Unfortunately, only the BBD building blocks for 1024 and 2048 steps are still being produced, so that at some point the other BBDs will no longer be available. The BBDs with 256 and 512 steps are currently phased out models. Status: January 2023 BBDs – “Bucket Brigade Devices” are based on (analogue) storage components for … Read more

A-110-4 Quadrature Thru Zero VCO

First of all: Wow, what a pompous name! “Quadrature Thru Zero VCO”! That sounds at least like Warp 11, quantum flux compensators and things like that, doesn’t it? The name is actually only topped by the A-110-6 “Trapezoid Thru Zero Quadrature VCO” – we’ll talk about that in a later blog post in this hyperspace … 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-143-9 Voltage Controlled Quadrature LFO/VCO

The A-143-9 Voltage Controlled Quadrature LFO / VCO is a voltage controlled sine wave generator that produces a very clean sine wave signal. With approx. 3 kHz, the LFO reaches into the audio range, with an additional control voltage it can even be used as a VCO up to approx. 20 kHz. Compared to “real” … 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-110-1 Standard VCO

The A-110-1 is Doepfer’s “standard” oscillator. The “standard” sounds a bit disrespectful, is that something like a “cheap VCO with economy sound”? In terms of sound, the A-110-1 does not have to hide, not even from significantly more expensive oscillators! First of all, the waveforms on the oscilloscope don’t all look “exactly mathematical”, especially the … Read more