doepfer
System A - 100
Sequencer Controller
A-154
1
1. Introduction
Module A-154 is a
supplement
to the
Analog/Trigger
Sequencer A-155
. It offers a lot of new features that are
not available in the basic control unit of the A-155. The
A-154 is used to replace the control unit of
one or two
A-155
, i.e. the section marked "Control" with Start / Stop
/ Step / Reset buttons and inputs in the upper left corner
of the A-155 front panel. If the A-154 is used to control
the A-155 the control section of the A-155 is put out of
action.
These are the most important features of the A-154:
•
5 different running modes
: forward, backward, pen-
dulum, random, CV controlled step adressing. All
modes are available as
loop
or
one-shot
•
Manual and
voltage controlled selection
(with at-
tenuator) of the
running mode
•
5+1 LED display
for the 5 different current modes
and one LED for loop/one-shot display
•
Manual
and
voltage controlled selection
(with at-
tenuator) of
first and last step
of the sequence
•
In the "
CV Controlled Step Address"
mode the First
Step section is used to determine the active sequen-
cer step (in this mode the first/last step feature is not
available). Consequently manual and
voltage con-
trolled selection
of the active step
is possible
•
Internal
voltage controlled clock generator
with
manual and
voltage controlled
(with attenuator)
clock rate
, enables variable time length for each
step, e.g. controlled by one of the analog rows of the
A-155
•
Skipping
of steps, e.g. the gate row of the A-155 can
be used to control the skipping of steps
•
LED display
of the clock signal
•
Manual and
voltage controlled
(with attenuator)
pulse length
of the clock signal. This features enab-
les
different gate length
(at the same clock rate)
for
each step
, e.g. one of the CV outputs of the A-155
can be used to control the PW
•
One or two A-155
can be
controlled
from the A-154
•
8/16 step
mode: In combination with
two A-155
one
can select between
parallel (8 steps)
or
serial ope-
ration (16 steps)
. The serial operation requires addi-
tional
voltage controlled switches
(e.g A-150)
•
Manual and voltage controlled selection
between
"old" control unit of the A-155 and A-154 control
(
A-154 Master
on/off function)
•
With the
One-Shot modes
the A-155/A-154 combi-
nation can be used e.g. as a
complex envelope
generator.
One analog row determines the levels of
the envelope. The second analog row can be used to
adjust the time length for each step
•
The A-154 requires
at least one A-155