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System a - 100, A-109, Controls – Doepfer A-109 Voltage Controlled Audio Signal Processor User Manual

Page 5: Doepfer

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doepfer

System A - 100

VC Signal Processor

A-109

5

3. Controls

1

Level

Use this attenuator to control the amount of signal
entering the filter input "Audio In 1".

H

If the filter distorts, turn this control down, unless
you deliberately want the distorted sound as a
special effect. The audio input is very sensitive
so that distortion is possible even with normal
A-100 levels. Distortion appears about from po-
sition 5 with normal A-100 audio levels.

2

Frq.

Control 2 is used to adjust the filter frequency manu-
ally, i.e. the cut-off frequency f

C

of the filter.

In the maximum position of this control the low pass
filter is open. The more you turn down this control, the
more the high frequencies are filtered. The sound
becomes mellower and less bright (see Fig. 2) until at
0 the filter is completely shut, and there will be no
output signal at all.

The actual filter frequency results from the sum of the
manual control 2 and the external control inputs CVF1
and CVF2.

Fig. 2: Frequency response of the filter

3

CVF1

For voltage control or modulation of the cut-off fre-
quency
, use the frequency CV inputs ". Use attenua-
tor 3 to adjust the control voltage level of the fre-
quency CV input CVF1.

Frq. / CVF

Freq.

Res. / CVQ

Out

f

C