Manual

DOEPFER System A-100 Synthesizer Voice A-111-5
17
16 ADSR Range Switch
17 ADSR Attack Time
18 ADSR Decay Time
19 ADSR Sustain Level
20 ADSR Release Time
This group of elements is responsible for the adjustment of
envelope generator (ADSR).
Switch 16 is used to select the time range:
upper position: low ~ 0.1s ... 100s
center position: high ~ 200us ... 0.2s
lower position: medium ~ 2ms ... 2s
The times are specified for Attack. The Decay and Release
times are about 3-5 times more because of their asymptotic
character. E.g. in the Release state the envelope
approaches the zero level in an asymptotic curve and it's
difficult to define the release time (see picture on the right
side).
The lower position is the standard time range. The center
position is mainly for very short and percussive sounds,
where the overall envelope time may be even shorter than
one period of the VCO signal (e.g. a 200Hz VCO signal has
a period of 2 ms, the shortest envelope time in the "high"
range is about 400us which is only 20% of the VCO period).
The low range is intended for very long envelopes up to
several minutes.
As the time ranges overlap certain envelope times can be
generated in two ways (e.g. 50ms is covered by high and
medium range).
The following picture shows the typical envelope curve of an
ADSR signal:
The picture shows the curve for medium settings of A, D, S
and R. As the values of the four parameters can vary over a
wide range the actual envelope may look totally different.
A more detailed description of the ADSR envelope can be
found in the user manuals of other A-100 envelope
generators (e.g. A-140, A-141 or A-143-2).
Attack
Decay Release
Sustain