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Redback® Proudly Made In Australia 19
2.8 Pre-Amp Out, Tape Out, Send & Return
Pre-Amp Out
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).
Tape Out
Dual RCA’s are provided for the “Tape Out” connection for recording purposes. This level is post master volume so it is
affected by the master volume.
Send and Return
RCA connectors are provided for the send and return audio paths. 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 (this is factory fitted). The amplifier will not work without this link. Only when an
external effects unit is used can it be removed.
Fig 2.8 illustrates the connections required for a slave amplifier, a recording unit and an effects unit.
2.9 Backup Battery Charging
If the amplifier is connected to backup batteries the amplifier
is provided with a trickle charge circuit to maintain the batter-
ies 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. (Refer to fig 2.9 for connection details)
Fig 2.8
Setup
4 -16Ω
70V
100V
OUTPUTS
L
R
24V DC IN
Balanced Mic
+_
PTT
(short to
activate)
Power Fail
(Contacts
close on
power fail)
Send
Return
Tape Out
Preamp Out
Link To Charge
Backup battery
Input 1
Input 3
Input 2
Input 4
Input 5
Input 6
ALERT - EVAC MODULE
Output Levels
Voice Chime Alert
Over
& Evac
EV
COM
CAN
CH
AL
Triggers
L
R
+ –
Rem. Vol
Connect
to 1K
Ω
Pot
+
–
+
–
+
–
Line
24V DC
Switched
Output
DIP 5
Interface
DIP 4
DIP 1
DIP 2
DIP 3
Balanced Mic
Line
Balanced Mic
Line
Balanced Mic
Line
Balanced Mic
Line
Balanced Mic
Line
Balanced Line
L
R
L
R
L
R
L
R
L
2
1
3
2
1
3
2
1
3
2
1
3
2
1
3
2
1
3
2
1
3
1 2
3
4 5
6
7 8
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
230V AC @ 50Hz
w
w
w
.altr
onics
.com.au
RESETTABLE
DC FUSE
Made in Australia
by Altronic
Distributors
Pty Ltd
DIP 5
DIP 4
IMPORTANT NOTE
Ensure power is switched OFF when
adjusting DIP switches. New
settings will be effective when
power is switched back on.
DIP 3
SW
Item
On
Off
1
2
Input 6 Level 1V
100mV
3
Not USed
4 Input 5 Level 1V
100mV
Not USed
1
2
3
4
DIP 2
SW
Item
On
Off
Input 4 Level
1V 100mV
Not USed
Input 3 Level
1V 100mV
Input 3 Priority
On Off
*
DIP 1
SW
Item
On
Off
1
2
Input 2 Level
1V 100mV
3
Input 2 Priority
On Off
4 Input 1 Level
1V 100mV
Input 1 Priority
On Off
**
SW
Item
On Off
1
2
3
4
Not Used
Not Used
Not Used
Not Used
DIP 4
DIP 1
DIP 2
DIP 3
SW
Item
On Off
Switched 24VDC Out
On Off
Phantom Power Input 6
On Off
On Off
1
2
3
4
Phantom Power Input 5
On Off
5
Phantom Power Input 4
On Off
6
Phantom Power Input 3
On Off
7
Phantom Power Input 2
On Off
8
Phantom Power Input 1
Preamp Out
†
Post
Pre
†
Sets the Preamplifier output to
Pre or Post Master.
DIP 5
Priority or VOX muting is only
functional on inputs 1-3. When
VOX is enabled on input 1 it will
override all other inputs includ-
ing the Alert/Evac Module. VOX
enabled on input 2 will override
inputs 3-6. VOX enabled on input
3 will override inputs 4-6.
If the Alert/Evac module is fitted
it will override inputs 2-6.
*
Model 125W
5A
AC Fuse
250W
7.5A
AC Fuse Ratings
RISK OF ELECTRIC SHOCK
OPEN BY QUALIFIED
PERSONNEL ONLY
!
CAUTION
POWER
REDBACK
A 4270 125W
Public Address Amplifie
PHASE
5
SLAVE AMPLIFIER
EFFECTS UNIT
RECORDER
LINK THESE TERMINALS
+
-
24V DC IN
+_
PTT
(short to
activate)
Power Fail
(Contacts
close on
power fail)
Send
Return
Tape Out
Preamp Out
Link To Charge
Backup battery
ALERT - EVAC MODULE
Output Levels
Voice Chime Alert
Over
& Evac
EV
COM
CAN
CH
AL
Triggers
L
R
+ –
Rem. Vol
Connect
to 1K
Ω
Pot
24V DC
Switched
Output
DIP 5
Interface
Balanced Line
2
1
3
1 2
3
4 5
6
7 8
1
2
3
4
DIP 5
DIP 4
Fig 2.9
