Doepfer A-100(~ 40 MB) - Manual (Page 246)

A-117 Digital Noise Generator System A - 100 doepfer
4
5. User examples
Module A-117 is an inexhaustible source of scraping,
lip-smacking, bell or other untuned percussion sounds,
so the following examples should be taken just as
starting points for further experimentation.
Random clock pulses
With low pulse rate settings, the A-117’s output ! is a
source of randomly sequenced clicks or clocks. You
can use these for modulating a variety of things - for
instance the final ADSR in a patch, to produce sudden
sharp peaks in the filter cut-off point.
Alternatively, you can use the clock pulses to control
the voltage controlled switches A-150 and A-151, or
the clock divider / sequencer A-160/161. Relevant
patches can be found in the manual sections fo r the
respective modules.
The patch in Fig. 2 shows another application, where
the clock pulses are used with a filter for sound
creation.
It uses the ability of a filter to ‘ring’: if you patch a pulse
with a steep rising edge into a filter, it can set the filter
into a brief burst of resonance. Depending on the filter
type, different settings of the cut-off point and reso-
nance amount can lengthen a click into bell-like
sounds.
For example, if you use the 12dB band pass filter
output on the A-121, with the cut-off set at around 5,
and resonance set just below self-oscillation, you can
create effective dripping sounds. A slow LFO (c. 5
Hz) modulating the filter cut-off point, makes each drip
sound different.
Fig. 2: random production of dripping sounds
Use the filter’s resonance control to adjust the nature
of the sound, from a drier, cracking / clicking type of
sound (with little resonance) to a wetter, tinkly / bell-
like sound (with the resonance set high, just below
self-oscillation).
A-117
RND
ADSR A-121
6
LFO
FCV