Doepfer A-117 Digital Noise / 808 Source - Manual (Page 5)

doepfer System A - 100 Digital Noise Generator A-117
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Change the band pass for a high pass filter, put the
cut-off to high and the resonance to minimum, and
summon up a hailstorm.
P Experiment with different filter kinds, and
settings for cut-off and resonance. You’ll
find all sorts of combinations of settings and
filter types that produce well usable percus-
sion sounds.
The A-117 as noise generator
At higher pulse rates, digital noise is available at
output !. For example, you can add this unfiltered to
other sounds. In Fig. 3, a patch for an 808-like bass
drum sound uses a VCA, two ADSRs (one with a very
short envelope) and a band-pass filter, to create a
burst of bass energy. This standard bass drum sound
benefits from filter ringing - see above.
P Again, this basic patch will work well with
other filter types, and cut-off and resonance
settings, to produce different sounds like tom
and snare drums.
Fig. 3: Producing bass drum sounds
"Playable" noise
If you patch a VCO’s square wave output into the
external clock input, the frequency of the digital noise
follows the pitch of the VCO, to produce a sort of
pitched noise. Best for this is the High End VCO
A-111, which has a greater usable frequency range
than the standard VCO A-110.
A-117
Gate
VCA
ADSR 1
A-138 RND
A-121
Band
ADSR 2