Doepfer A-100(~ 40 MB) - Manual (Page 15)

doepfer System A - 100 3. A-100 signal flow
9
Trigger or Gate Signals, which start a process or
function, are typically from 0 V to +5V or 0V to +12 V,
with the trigger occurring as the
leading edge of the
waveform shoots up from 0 V to +5V/12 V. The A-100
modules usually output +12V, but the corresponding
inputs of A-100 modules (e.g. Gate, Clock, Reset) will
also work with lower levels (typ. +5V).
These definitions of the various signals, and the di-
stinctions between them - sound sources and modula-
tion sources - are right in principle, but a modular
system like the A-100 often makes a mockery of them.
In a modular set-up, all of the modules produce volta-
ges, and can be used as control voltages or triggers,
thus blurring the distinction between the various types.
For example, the output from an LFO can be used as
an audio signal, as a control voltage for a VCF or VCA,
or as a trigger signals for a sequence.
It’s just about true to say that anything can be modula-
ted by anything else, so that a modular system gives
the musician extraordinary flexibility and individuality.
3.3 The System Bus in the A-100
The A-100’s
System Bus supplies power to the modu-
les. It also carries the internal control system
(
INT.GATE and INT.CV), which some of the modules
(such as the VCO A-110, or ADSR A-140) can tap into.
You can choose whether these modules receive these
signals, by altering an internal jumper.
Fig. 7: The A-100 system bus
If you use a MIDI/USB-to-CV-Interface in your system,
when you press a key on your MIDI keyboard, the gate
and CV signals from the interface can be sent via the
INT.GATE and INT.CV to all modules on the bus
when the jumpers of the affected modules are installed
in the right way.
The INT.GATE and INT.CV signal busses can be
split
into two equal halves by removing jumpers J1 and
J2 (see Fig. 7), so that for each whole bus, you can
have two separate
CV/GATE subsystems.
INT. Gate
INT. CV
+5 V
+12 V
GND
-12 V
1 7 8 14
J1
J2