DOEPFER A-100 Series Manual

Browse online or download pdf Manual for Control Unit DOEPFER A-100 Series. DOEPFER A-100 Series 8 pages. Analog modular system, connecting the breakout module to the main module
Also for DOEPFER A-100 Series: Operating Instructions Manual (8 pages), Manual (16 pages), User Manual (12 pages), Assembly And Wiring Manual (6 pages), Manual (8 pages), Manual (6 pages), Connecting (8 pages)

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doepfer

Level

Audio

FCV 1

FCV 2

QCV

Audio

Out

System A - 100

A-122

VCF 3

Frequency

Resonance

1. Introduction

The modules A-105 and A-122 are voltage-

controlled low-pass filters, which filter out the higher

parts of the sound spectrum, and lets lower frequen-

cies pass through.

The cut-off frequency determines the point at which

filtering takes effect. You can control this manually, or

by voltage control (filter modulation, for instance by

an LFO). Two CV inputs are available. The cut-off

slope is -24 dB/octave.

Voltage controlled resonance: for both A-105 and

A-122, resonance can be controlled not just manually,

but by voltages as well, right up to self-oscillation. In

this case, the filter behaves like a sine wave oscillator.

The A-105 is based on the special circuit SSM2044,

that was used in several devices of the companies

Korg (Polysix,

Mono-Poly),

(Prophets, Pro-One), PPG, Fairlight, Emu and Kawai.

The circuitry of the A-122 uses a chip of Curtis Elec-

tromusic (CEM), and is very similar to the classic

Oberheim filter sound. Because of the different cir-

cuits the A-105 and A-122 have considerably different

sounds and even sound different compared to the

other filters (e.g. A-120 Moog low pass, A-102 Diode

Low Pass or A-103 18dB low pass, A-124 Wasp filter).

As the functions and controls are the same for both

modules they are a combined in one manual.

A-105 / A-122

Sequential

Circuits