105
20.5
Backup Amplifier
Any amplifier may be designated as a backup amplifier when backup is required. It should be
installed in any audio cabinet and in the right-most slot position of a QMB-5000B backplane.
Figure 65
QAA-5160-70/25 Amplifier (Backup Application)
Any amplifier may be
designated as the backup
amplifier and this backup
amplifier must have the MD-
789 molex connector
placed in the bottom left-
hand corner of the board as
shown in the adjacent
figure. The QAA-5160-70/
25 as backup amplifier is
inserted into the
motherboard. No
connections are made to
the backup amplifier's
terminals except for end-of-
line resistors which are to
be placed directly on the
terminals in the audio
cabinet.
Once the Backup Amplifier
is installed, it must be
properly configured. Refer
to the Audio Configuration
for details.
The number of backup
amplifiers is limited to one
per node. Only the first
failed amplifier gets the
backup. The distance from
the farthest audio cabinet to
the audio cabinet (which
has the backup amplifier)
cannot be greater than four
cable lengths
(approximately 208 inches
or 17 feet).
MO
THERBO
ARD
C
ONNECT
OR
CAPACITORS
XMFR
HEAT SINK
HEAT SINK
XMFR
SPEAKER
TERMINALS
RELAYS
MOLEX CONNECTOR
MD-789 MUST BE CONNECTED
ON BOARD HERE TO USE
AMPLIFIER AS A BACKUP