doepfer
CV A
CV D
CV S
CV R
Gate
VCADSR
Retrig.
CV A
CV D
CV S
CV R
Output
A-141
Attack
Decay
Sustain
Release
System A - 100
1. Introduction
Module A-141 (VCADSR) is a voltage controlled
envelope generator.
Whenever a
gate input, an adjustable sequence of voltages is
triggered - the envelope. You can then use these
envelopes to modulate a VCO, VCF and/or VCA, and
alter the input and output voltages of all sorts of
modules.
The shape of the envelope is governed by four parameters: Attack, Decay, Sustain and Release (see Fig.
1 on page 3). On the A-141, these parameters can be
controlled by hand, or by voltage control, via the
dedicated CV inputs (each with an attenuator).
The A-141 VCADSR also has a retrigger facility:
while the gate is open, a trigger pulse received at the
retrigger socket will
beginning of its attack phase (see Fig. 2 on page 5).
gate signal
re-start the envelope
VCADSR A-141
is sensed at the VCADSR’s
from the
1
A-141
VCADSR
System A - 100
doepfer
2. VCADSR - Overview
A-141
Voltage Controll. Envelope Generator
CV A
➊
0
CV D
➋
0
CV S
➌
0
CV R
➍
0
➎
Gate Retrig. Out
10
10
10
10
VCADSR
0
0
0
0
Controls and indicators:
A : Attack time control
1
2 D : Decay time control
S : Sustain level control
3
R : Release time control
A
10
➀
➄
D
10
➁
➅
S
10
➂
➆
R
10
➃
➇
➈
4
... 8 : Attenuators for CV inputs ! to
5
9 LED : Envelope state indicator
In- / Outputs:
!
CV D : Decay voltage control input
"
§
CV R : Release voltage control input
$
% Gate: Gate signal input
&
Output: Envelope voltage output
/
: Attack voltage control input
CV A
: Sustain voltage control input
CV S
Retrig.
: Retrigger signal input
$
➏➐
2
doepfer
➨
System A - 100
VCADSR A-141
3. Controls and indicators
As soon as a gate signal is sensed at the VCADSR
gate input 5, the VCADSR puts out a varying voltage,
changing in time, known as an envelope. See Fig. 1.
Attack
Time
ca. +8 V
On
: ADSR envelope and its parameters
Fig. 1
The parameters A, D, S and R can be adjusted by
hand with controls 1 to 4, or can be controlled by the
voltages patched into CV inputs ! to $. These control
voltages and the voltages set by hand are summed.
Decay
Time
Sustain
Level
Release
Time
Time
+3 ... +12 V
Off
0 V
1 A
This controls the Attack time of the envelope.
Whenever the VCADSR is triggered - by a key being
pressed on your controller keyboard, or by an external
gate being sensed at the gate input 5 - the control
voltage at output 7 rises to the maximum, in a time
determined by the setting of this knob, and any voltage
patched into its Attack CV input.
D
2
This controls the Decay time of the envelope. After
the attack phase is finished, the voltage falls to the
level set by the sustain knob and CV, in a time
determined by the setting of this knob, and its CV
input.
3 S
This controls the Sustain level of the envelope. After
the decay phase, the voltage stays at this level until
the gate is released.
4 R
This controls the
signal finishes, for instance when the key on the
controller keyboard is released (Note Off in MIDI), the
voltage at the output falls to its minimum, in a time
determined by this knob and the Release CV.
Release time
. As soon as the gate
3
A-141
VCADSR
System A - 100
doepfer
5 CV A ... 8 CV R
Attenuators 5 to 8 set the level of voltage control
for inputs ! to $.
LED
9
The LED indicates the level of the envelope’s voltage.
4. In- / Outputs
! CV A ... $ CV R
CV inputs ! to $ are where the voltages you want to
use to control the envelope parameters are patched.
% Gate
Socket % is the VCADSR’s gate input.
& Retrig.
Socket & is the VCADSR's
where you patch in a voltage to re-trigger the envelope. If, for instance, you patch an LFO in, then while
the gate is open, the envelope is re-triggered every
time an LFO pulse is received (see Fig. 2).
retrigger input.
This is
Output
Gate
Retrig.
Fig. 2: Envelope re-triggering
/ Output
Output socket / is where the envelope determined
by the A, D, S, and R parameters is available, every
time the VCADSR is triggered (see Fig. 1).
4
doepfer
System A - 100
VCADSR A-141
5. User examples
Basically, the envelope generated by the VCADSR
can be used for any number of types of modulation:
• VCADSR - VCA
Complex amplitude changes over time
• VCADSR - VCA for voltage control
Time-dependent control of all sorts of modulation
voltages to and from other modules
VCADSR - VCF
•
Modulation of the filter cut-off frequency for constantly evolving
• VCADSR - VCO (PWM)
Time control of
for evolving timbres
• VCADSR - VCO (FM)
Pitch modulation as notes progress (and timbral
change with very short envelope settings).
Look in the individual manuals for further examples
and notes.
The VCADSR in a MIDI system
In contrast with the A-140 standard ADSR, the A-141’s
parameters can be voltage controlled. One particular
possibility is to control the changes in parameters with
sound spectra
Pulse Width Modulation
changes
a MIDI sequencer and MIDI-CV interface (for instance, the A-191) by simply sending MIDI controller
messages.
That actually makes the ADSR parameters program-
, and also means that you can change them as
mable
you play, in real time (for instance by using velocity to
control the Decay parameter).
Using the VCADSR with a sequencer
Used in conjunction with a sequencer like the MAQ
16/3, you can get some interesting results - for instance programming a different VCF or VCA decay
time for each note in a sequence. You simply
connect the second CV output of the MAQ 16/3 to
input " (CV D) on the A-141 which is patched into the
VCF or VCA.
Controlling the release time
A common VCADSR application is shown in the patch
in Fig. 3, where the higher the note played, the shor-
ter the release time. This mimics the natural behaviour of most acoustic instruments.
The A-175 Voltage Inverter simply inverts the pitch CV
and sends it to the release CV input $ (CV R). You
control the intensity of this effect with control 8.
5
A-141
VCADSR
System A - 100
doepfer
CV
Gate
A-175
VCO
VCA
A-141
VC R
Fig. 3: Controlling release time
The same basic system can be used, eg, to shorten
the attack phase the higher the velocity sensed;
playing hard produces a short attack, and playing
more gently a slower attack to the note. Simply patch
the relevant velocity output of a MIDI-CV interface,
(for instance output CV2 on an A-190) to the A-175
Voltage Inverter's input, and the A-175’s output to the
CV input ! (CV A) of the VCADSR.
Random/cyclical parameter changes
You can get some interesting results by modulating
ADSR parameters either at random, with the random
output from an
A-118 module,
or
cyclically
, by using
an LFO such as the A-145, A-146 or A-147.
This is where creativity and love of experimentation
get to be really important - but one suggestion at least
is that the Decay parameter is a good one to start with.
In the patch in Fig. 4, each new note has a different
(random) decay.
CV
Gate
A-118
VCO
Random
Out
VCA
A-141
CV D
A-148
Trig In
Fig. 4: Random decay with each new note
6
doepfer
System A - 100
VCADSR A-141
7
A-141
VCADSR
6. Patch-Sheet
System A - 100
doepfer
The following diagrams of the module can help
you recall your own Patches. They’re designed so
that a complete 19” rack of modules will fit onto an
A4 sheet of paper.
Photocopy this page, and cut out the pictures of
this and your other modules. You can then stick
them onto another piece of paper, and create a
diagram of your own system.
Make multiple copies of your composite diagram,
and use them for remembering good patches and
set-ups.
P • Draw in patchleads with colored
pens.
• Draw or write control settings in the
little white circles.
A-141
Voltage Controll. Envelope Generator
CV A
0
CV D
0
CV S
0
CV R
0
Gate Retrig. Out
10
10
10
10
VCADSR
0
0
0
0
A-141
Voltage Controll. Envelope Generator
CV A
A
10
D
10
S
10
R
10
0
CV D
0
CV S
0
CV R
0
Gate Retrig. Out
10
10
10
10
VCADSR
10
0
10
0
10
0
10
0
A
D
S
R
8
Loading...