Altec Lansing 9441A - Manual (Page 8)

Operating and Service Instructions for the Altec Lansing 9441A Power Amplifier
function of the output signal vol­
tage. As a result, the amplifier can
deliver the rated currents into
rated
loads but substantially
limits the current into low imped­
ance or shorted loads (shorted
output terminals). Once the short
is removed, however, the amplifier
will resume normal operation.
The heatsink is conventionally
cooled.
Slioxild the heatsink
temperature of a channel remain
excessively high, both chamiels
will .shut down automatically.
Wien the output devices cool to a
safe operating temperature, the
channels will automatically re­
sume normal operation.
5.3 Protect Indicator
I'he “PROTECT” LED
illuminates when either channel
enters thermal protection. If a
shutdown does occur, the chan­
nels will resume normal operation
as soon as its devices have cooled
to an acceptable temperature.
If the protection LED illuminates
and there is no indication of ex­
cessive temperature, one, or both,
of the channels is in an internal
fault mode. If this occurs, refer to
the service instructions on page
12 .
G OPERATION
G.l D u a l M o d e o f
Operation
In the dual mode of opera­
tion, the channels may be
operated independently. After in­
stallation and hookup, verify that
the mode switch, located on the
rear panel, is in the “DUAL” posi­
tion and rotate the level controls
fully counterclockwise (full atten­
uation). Input a 0 dBu (0.775 V
rms) nominal signal level and
apply power. Slowly increase the
level controls until the desired
output power is obtained. If either
“CLIP” LED illuminates, reduce
the outjnit with the channel level
control or reduce the input signal
level at its source.
WARNING: Never attempt to con­
nect the outputs of the two chan­
nels in parallel.
6.2 B r i d g e M o d e o f
Operation
After installation and
hookup, verify that the mode
switch, located on the rear panel,
is in the “BRIDGE” position.
Rotate both levels controls fully
counterclockwise (full attenua­
tion). Input a 0 dBu (0.775 V rms)
nominal signal level into channel
1 only and apply power. Slowly in­
crease the level control of channel
1 until the desired output power
is obtained. If either “CLIP” LED
illuminates, reduce the output
level with the level control or re­
duce the input signal level at its
soiirce.
CAUTION: Be sure that no input
connections are made to channel 2
and that its level control is fully
counterclockwise (OFF).
WARNING: The bridged output
mode provides a true halariced-to-
ground output. Do not use any test
equipment to test or evaluate tins
amplifier which does not have
floating grounds.
items:
1 .
2.
3.
4.
In Case of Problems
Please check the following
Verify that tlie amplifier
is properly coimected to
an ac power source and
that the source is active.
Verify that the input
connections are properly
made. Refer to Figure 3.
Verify that the output
comiections are properly
made. Refer to Figure 4.
Check the input and out­
put cables for proper
‘ wiring and continuity,
5. Check the signal source
and the load.
6. Ensure that the two
jumpers for each octal
socket are properly in­
stalled (if not using op­
tional plug-in modides).
7. Ensure that any aece.ssory
modules installed do not
draw more than i'u ma
DC of current.
8. Check that the mode
switch is in tin; •' :ured
position.
NOTICE: Repairs performed, by
other than authorized wananiy
stations (Dealers) or q: 'ified
personnel shall void the ivm—anty
period of this unit. To avoid loss
of warranty, see your neare;-; Altec
Lansing authorized dealer, or call
Altec Lansing Customer e-ervice
directly at (405) 324-531' Fc\X
(405) 324-8981, or write:
Altcc Lansing Customei
Sciwice/Repair
10500 W. Reno
Oklahoma City, OK 73128
U.S.A.
AIAEC LANSING^ CORPORATION o o Mark T\^ Company