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Installation
The NJS400 must be installed by a competent electrician in accordance with the
current IEE wiring regulations.
Connect the NJS400 to the mains supply (nominally 230V AC).
The NJS400 must be earthed. NEVER disconnect the earth, even in an attempt
to prevent „hum‟. If the earth were disconnected, it could result in equipment
connected to the input (even indirectly through a mixer), such as microphones,
becoming live in the event of a fault (such as a liquid spillage into the amplifier).
Install the NJS400 away from sources of moisture; avoid areas where drinks can
be spilled onto the amplifier as this may cause serious damage.
Avoid using microphone leads longer than 5 m. If longer microphone cable runs
are required, then an amplifier with balanced-line microphone inputs is required.
For connection of 100 V line loudspeakers, two-core 0.75mm
2
cable, such as
E548AC should be used. Loudspeaker cables may not be run in the same
conduit as mains cabled.
100 Volt line loudspeakers.
The 100V line system was developed to allow a long distance between
loudspeakers and the amplifier, and to allow a large number of speakers to be
connected to each amplifier.
In order to do this, the audio is transmitted at a much higher voltage (100V rms)
than with a conventional low-impedance amplifier, such as a hi-fi or disco
amplifier.
Each loudspeaker is coupled to the amplifier by an inbuilt transformer. The
transformer is generally fitted with a switch or a set of terminals that can be used
to select the power supplied to the speaker. Thus, every loudspeaker connected
to the 100V line can be set to the most appropriate power level.
Inputs
Microphones:
Connect the main microphone to the socket on the front panel. Use a mono
6.3mm jack plug. If the microphone has a screened two-core cable, connect one
core to the screen.
Connect any auxiliary microphones to the MIC2 and MIC3 sockets on the rear
panel.
Line inputs:
Connect any line inputs (such as radio, CD player, MP3 player) to the LINE1,
LINE2 and LINE3 inputs on the rear panel using RCA phono plugs. These are
generally used for background music.