Read JBL LC-A 304 (serv.man2) User Guide / Operation Manual online
Wiring the Input-Signal Connections
Connect a pair of signal cables with RCA-type ends between the connectors
on the amplifier and the RCA-type signal connectors on the source unit. If
your radio has only speaker-level outputs, you must purchase a speaker-
level-to-line-level adapter, commonly sold as an accessory.
System Setup and Adjustment
Refer to figures 1–4 for location of adjustment switches and controls.
Electronic Crossover (for LC-A752 and LC-A504)
The electronic crossover can be selected as a 12dB/oct high-pass filter
(HPF), 12dB/oct low-pass filter (LPF) or it can be defeated (FLAT). The
crossover frequency can be set at any frequency between 32Hz and 320Hz.
Setting Input Level
Initially, turn the input-sensitivity LEVEL control to its maximum
(counterclockwise) position. Turn on the source unit and increase the
volume control until it is approximately three-quarters of maximum-
output level. Slowly increase the input LEVEL control (clockwise) while
listening to the quality of the reproduced sound. When you hear distor-
tion on the music peaks, turn the LEVEL control back slightly. This is
the maximum undistorted output level of your system. Turning the
LEVEL control up farther WILL NOT INCREASE THE OUTPUT
POWER OF YOUR AMP! It will only decrease the amount of volume
control rotation before the amp is at full output power. It will also
increase the amount of extraneous noise present in your system.
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Figure 3
Figure 1
Model No. LC-A502
Model No. LC-A752
Model No. LC-A304
Model No. LC-A504
Figure 4
Figure 2
REM
BATT(+)
FUSE
20 AMP
GND (-)
POWER
POWER
FRONT PANEL
REAR PANEL
FRONT PANEL
REAR PANEL
FRONT PANEL
REAR PANEL
FRONT PANEL
REAR PANEL
OUTPUT
LINE INPUT
INPUT
LEVEL
LEVEL
LEFT
LEFT
BRIDGED
RIGHT
RIGHT
4V 250mV
REM
BATT(+)
FUSE
20 AMP
GND (-)
POWER
POWER
REAR
OUTPUT
LINE INPUT
FRONT
REAR
LINE INPUT
INPUT
LEVEL
LEVEL
INPUT
LEVEL
LEVEL
LEFT
LEFT
LEFT
BRIDGED
RIGHT
FRONT
OUTPUT
LEFT
BRIDGED
RIGHT
RIGHT
RIGHT
4V 250mV
4V 250mV
REM
BATT(+)
FUSE
20 AMP
FUSE
20 AMP
GND (-)
POWER
REAR
OUTPUT
LEFT
BRIDGED
RIGHT
FRONT
OUTPUT
LEFT
LEFT
LEFT
BRIDGED
RIGHT
RIGHT
RIGHT
LINE INPUT
LINE INPUT
CROSS
OVER
CROSS
OVER
FRONT
REAR
INPUT
LEVEL
4V 250mV
4V 250mV
INPUT
LEVEL
POWER
LPF
HPF
FLAT
LPF
HPF
FLAT
32Hz 320Hz
FREQUENCY
32Hz 320Hz
FREQUENCY
LEFT
RIGHT
LINE INPUT
CROSS
OVER
INPUT
LEVEL
4V 250mV
POWER
LPF
HPF
FLAT
32Hz 320Hz
FREQUENCY
REM
BATT(+)
FUSE
25 AMP
GND (-)
POWER
OUTPUT
LEFT
BRIDGED
RIGHT
LC-Amplifier OM 3/4/99 10:55 AM Page 4
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