DOEPFER A-100 Manual

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Fig. 1: A-188-2 Controls and In/Outputs
System A-100
1. Introduction
Module A-188-2 based on a so-called Bucket Brigade
Device (abbr. BBD). In contrast to the A-188-1 the A-188-
2 uses a tapped BBD circuit, i.e. the circuit has available
six different outputs at the BBD stages 396, 662, 1194,
1726, 2790 and 3328. Each of the taps is available as a
single output but the module features also two mixing
sub-units. For both mixers the levels and polarities of
each BBD output can be adjusted to obtain two different
mixtures. Each mixer has a wet/dry control that allows
choosing between the original signal, the BBD mix or
anything in between. The outputs can be treated as
stereo outputs but that's not . Due to the six taps even six
different feedback types are possible. The feedback input
socket is normalled to the "396" output. But by patching
the feedback socket to any of the single output sockets
another BBD tap can be used for positive or negative
feedback to obtain different sounds. Even external
feedback processing is possible. The A-188-2 uses a
high speed VCO to generate the BBD clock. The clock
and consequently the delay time can be controlled
manually and by the two control voltage inputs CV1 and
CV2. CV2 is equipped with a polarizer. The module has a
clock output available that is normalled to the clock input
socket. These sockets can be used to link different BBD
modules and to run them with the same clock. A voltage
composed of the manual delay control, CV1 and CV2 is
available at the CV out socket, e.g. to control an external
clock suppression filter as the A-188-2 is not equipped
with such a filter.
BBD Module A-188-2
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