Plug-In Board Dds 3 - Rhythm - Wersi DX 400 Assembly Manual

7.

Plug-in Board DDS 3 - Rhythm

Fig. 14 shows the component layout of plug-in board
DDS 3; refer to Fig. 15, the schematic diagram, for the
following description.
Depending upon the instrument trigger pulses it receives
from the master data bus via 1C20, microprocessor 1C14
reads out percussion instrument sounds digitally stored
in digital sound modules IC23 thru lC26.
AM 334-01-502
These sounds appear at output pins 12 thru 19 of 1C9
as momentary digital data in multiplexed form. The
data is converted into an analog signal in DAC IC1.
The signal then goes to IC4, where its volume can be
controlled. The percussion sounds appear at the output
of 1C2 in the form of a multiplexed analog signal.
Demultiplexer IC5 routes each sounding instrument
to its own audio channel. The composite percussion
sounds are present at the outputs of the two sections
of 1C8 for further stereo processing.
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