JDM
®
6 Zone Public Address Amplifiers
4
REAR PANEL CONTROLS:
1. MIC PRIORITY SWITCH:
These are the priority-setting switches for microphone inputs 1, 2
and 3. To change priority ranking from No.3 to No.2 turn switch
lever to the right.
2. P.T.T PAGING CONSOLE INPUTS (RJ45 JACKS):
Not used (Note: Do not plug A4353 into these sockets).
3. MIC/LINE INPUT:
Inputs1-3 allow you to connect balanced microphone (XLR) or
line (TRS) sound sources. The GAIN knob varies the input signal
from -10dB to -50dB, depending on the type of source plugged
in. If the MASTER volume output LED meter flashes red, this
indicates clipping. Adjust the GAIN control to a level so that
clipping ceases.
The XLR and 6.35mm phono combo socket has been redesigned
for MIC/LINE input, and can supply phantom power to a
condenser mic connected via the XLR connection. Pin 1 on the
XLR and the sleeve on the phone jack are grounded.
IMPORTANT:
Turn the volume control on the front panel anti-
clockwise to decrease the level when you are using phantom
power, so as to avoid damaging the speakers.
4. LINE IN 4-5:
Inputs 4 and 5 are used for the connection of line-level
equipment such as a cassette deck or a CD-player. The stereo
signal of the connected sound sources is internally converted into
a mono signal.
5. REC:
Recording output has been installed using two unbalanced RCA
jacks. All signals can be recorded but recording output level (0
dB gain) cannot be adjusted by master volume, since it is wired
to be pre-fader. This output could be connected to a logging
recorder of some type.
6. AMP IN / PRE OUT:
A. AMP IN:
This unbalanced input is for a direct signal input from external
equipment (+4dB level). It is controlled by the Master volume
control on the front panel. A signal processor receiving a
signal from the PRE OUT can ‘return’ the processed signal to
the AMP IN.
B. PRE OUT:
This 6.35mm jack is for connecting an unbalanced line level
output signals to an external amplifier or a signal processor
such as an equalizer. The signal is pre-fader with respect to
the Master volume.
IMPORTANT:
The output impedance should be 600ohm for
pre-amp operation.
7. SPEAKER ZONES & ATT. OUTPUT:
Pushing a speaker zone selector button (front panel no.8) will
assign the Master Volume output signal to the selected zone. If
the ALL CALL button is pressed, the zone selector of remote
controller (A4353) is activated, and the selected zone output is
reset to 100v/70v output.
8. LOW/HIGH IMPEDANCE OUTPUT:
These spring terminals provide connections for either low
impedance (4ohm) or high impedance (100V) speaker output
in conjunction with A.T.T (Attentuator) control knobs for each
zone on the front panel. Only one or the other, not both
simultaneously. See Fig. 3.
9. TELEPHONE:
NIGHT RINGER:
Connect this terminal to telephone line so that you can hear
the telephone ring via speakers in other offices.
PAGING IN:
Connect this terminal to the telephone exchanger so that the
paging call can be heard through the telephone speakers.
10. MESSAGE FIRST PRIORITY:
This feature is currently unsupported.
11. DC POWER:
This terminal is for a battery connection to provide emergency
power to the unit. The battery connection cable has to be three
millimetres in diameter and should not be any longer than seven
meters. The fuse is located on the internal amp PCB at FU3.
AC POWER REMOTE:
Wiring these terminals enables the amplifier to be turned on
or off by remote control.
12. AC POWER INPUT:
Connect power plug and then switch the main power button to
ON position to begin operating the unit. Reverse the procedure
to remove unit from the wall socket. Remember to disconnect
the power cord to replace a blown power fuse, which is located
internally on the power PCB at FU1.
Figure 2:
Rear Panel Controls
