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Redback® Proudly Made In Australia
7
Overview
The A 4275/85 range of mixer amplifiers have provison to plug in an optional Alert/Evacuation module (A 4573). The
controls are listed below (see section 2.5 for more details).
2
Voice Over Volume
Use this trimpot adjustment to change the output level of the playback message.
3
Chime Volume
Use this trimpot adjustment to change the output level of the chime volume.
4
Alert and Evacuation Volume
Use this trimpot adjustment to change the output level of the alert and evacuation tone.
5
Alert, Evacuation, chime and cancel contacts
Use these contacts to trigger the chime tones, the alert tone, the evacuation tone and to cancel any
of the tones once triggered. All tones & cancel function are operated by a closing contact to ground.
This could be triggered via building fire indicator board, break glass alarm etc.
6
Preamp Out (Balanced Line Output)
A 3 pin 600ohm 1V balanced XLR output is provided for passing the audio signal on to other slave amplifiers
or to record the output of the amplifier. This output can be set up to be effected (post master volume) by the
master volume control or unaffected (pre master volume). Factory default setting disables the preout. (Refer to
section 2.3 DIP switch settings).
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Input connectors
There are 6 sets of inputs which can be either balanced mic or line inputs. The line inputs are dual RCA
connectors which are internally mixed to produce a mono input signal.
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DIP SW 1-3
Inputs 1-6 include an individual 4 way dip switch enabling adjustable input sensitivity (100mV or 1V) and Priority/
VOX muting for inputs 1-3.
Priority/VOX muting is not available on inputs 4-6.
Note, when the Priority/VOX muting function is selected (inputs 1-3) it will operate with the input set for either
microphone or line operation. (see section 2.3 for DIP Switch settings)
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Pre - amp send and return
This allows external effects units, ie Graphic EQ’S , companders or signal processors to be connected to the
amplifier. When not using this feature the send and return outputs must be linked externally (factory fitted). The
amplifier will not work without this link. Only when an external effects unit is used can it be removed.
(see section 2.8 for more details)
10
Tape Out
Dual RCA’s provided for recording purposes. This level is post master volume. (see section 2.8 for more details)
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DIP SW 5
These DIP switches set the 24VDC switched output status, determine the Preamp output as pre master volume
or post master volume and also set the phantom power to the balanced inputs. (see section 2.3 settings)
12
DIP SW 4
Not currently used.
13
RJ45 Interface
This is for future expansion of product.
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Battery Charging
The amplifier is provided with a trickle charge circuit to maintain the batteries in a charged condition. The charge
rate is approximately 300mA. Simply link the terminals marked “link to charge backup battery” on the rear of
the amplifier. A flat battery will generally take overnight to charge, or even longer depending on the battery
capacity. (see section 2.9 for more details)
