• Headphone Output:
The headphone monitor output is via a 3.5mm stereo jack socket located at the
bottom right of the circuit board. If a standard stereo headset is connected to this
socket, the output (and hence correct operation of the unit) can be monitored locally
before connecting it to the main amplification system. This would typically be done
during installation or after installing a new memory stick.
A diagram showing the location of the audio output
connectors is shown below:
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Audio Outputs:
The LB-5A has three audio outputs, each designed to suit different requirements;
unbalanced stereo, balanced mono and a headphone monitor.
• Stereo Output:
For ease of connection the stereo output
is via two phono sockets (the left and
right channels), mounted on the main
circuit board. The signals are unbalanced
(standard), requiring good quality audio
grade co-axial cables to connect them to
other equipment. The output signals are
at line level (775mV RMS) and should be
connected into the auxiliary or similarly
configured input on the amplifier or mixer
with which it is to be used. If required, it
is possible by means of the Jumper J10
located on the circuit board, to configure
these outputs to mono, allowing only
a single connection to the amplifier or
alternatively to use each output to feed
separate amplifiers.
• Balanced Mono Output:
The balanced mono output is designed to feed industrial public address systems
requiring a single mono signal and is via two screw terminals mounted on the circuit
board. This output uses a balanced configuration providing good noise immunity
to the signal and wiring in what can be electrically noisy environments. Connection
should be via good quality twin core and screen cable with the two cores being
connected to the two screw terminals.
Being balanced it is not critical which wire goes to which terminal, but it is good
practice to note which colour goes to the positive terminal and which one goes to the
negative, this ensures correct termination of the cable at the other end. The screen
of the cable should only be connected at the amplifier end, thus preventing any
currents flowing through it, which might in turn induce noise into the signal wires. The
output signal is at line level (775mV RMS).
22
Jumper 10
Mono/Stereo Select
