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www.redbackaudio.com.au

Redback® Proudly Made In Australia 15

Redback® A 4270/80

 Four Zone Paging PA Amplifier

Unit will not play MP3 files.

Make sure all MP3 files are not “Read Only”. See page 13

MP3 files should have the following specifications for optimum performance. 128kbps, 44.1kHz, 32bit, VBR or
CBR, Stereo (even better as mono).

.

20.0 SPECIFICATIONS 

 
POWER OUTPUTS 

Power: .......................................... A 4377 -125 watts RMS 
 

.........................................A 4387 - 250 watts RMS

Distortion:..................................................< 0.5%, @ 1kHz 
Output line: ............................................................... 100V  

FREQUENCY RESPONSE 

Mic inputs :...........................................50Hz - 12kHz, -3dB 
Line inputs: ...........................................50Hz - 15kHz, -3dB 

MIC SENSITIVITY 

Mic inputs: ................................................................. 3mV 
Line inputs:.....................................................................1V
Music input: ............................................................500mV

SIGNAL TO NOISE RATIO 

Mic inputs: .............................. > 75dB below rated output 

LINE OUTPUT 

.................. 600Ω balanced, 0dB , 3 Pin XLR

OUTPUT CONNECTORS

Speakers: ...................................................Screw terminals 

INPUT CONNECTORS 

Inputs: .................................3 pin XLR balanced or 2 x RCA 
24V DC power: ..........................................Screw terminals 
240V AC power: ............................... IEC power connector 

MUTING

:..................... PTT via microphone switch contacts 

 

........................................ VOX muting (inputs 1-2) 

CONTROLS 

Mic/Line/Music inputs: ............................................ Volume 
Power: ...........................................................On/off switch 
Indicators:......................Power, signal present, output peak 
limiting, overtemp ,Overload Protect, Half Power, 24V DC

POWER SUPPLY:

 ................................240V AC or 24V DC

FUSE PROTECTION

: ......................125W - 5A AC ,10A DC 

 

 

       ...................250W - 7.5A AC ,20A DC 

DIMENSIONS 

...................................≈483W x 300D x 88H

 

* Specifications subject to change without notice

All Australian made Redback products are covered by a 10 year warranty. 

Should a product become faulty please contact us to obtain a return authorisation number. Please ensure you have all the 
relevant documentation on hand. We do not accept unauthorised returns. Proof of purchase is required so please retain 
your invoice.

Summary of Contents for A 4270

Page 1: ...se read these instructions carefully from front to back prior to installation They include important setup instructions Failure to follow these instructions may prevent the unit from working as design...

Page 2: ...users reliable products of high build quality with local product support We believe there is significant added value for customers when purchasing an Australian made Redback amplifier or PA product Lo...

Page 3: ...Thermal overload overcurrent and overload protection circuitry and fuses on both AC and DC provide excellent fault condition protection and robust performance The amplifier also utilises a half power...

Page 4: ...tes when the input signal is clipping 11 OverLoad Indicator This LED indicates when the output is drawing too much current from the amplifier The output will be disconnected until the current draw is...

Page 5: ...ore details 7 Inputs 1 3 These inputs can be either a balanced XLR input with sensitivities of 500mV or dual RCA line inputs with a 1V input sensitivity The line input dual RCA connectors are internal...

Page 6: ...one inputs have DIP switch selectable phantom power When enabled 15V DC will be connected to the Hot and Cold pins of the corresponding XLR To access the DIP switches first disconnect power from the u...

Page 7: ...of connecting speakers in parallel and cable losses The amplifier generally has an output voltage of 100 volts 70 volts is typically used in North America however operation is similar In this configu...

Page 8: ...ging consoles can be connected as shown The paging consoles provide paging to all four output zones and will override the background music to those zones refer to section 13 0 for more details Fig 6 R...

Page 9: ...from the amplifier 2 RJ45 connector For connection back to the A 4270 or A 4280 Either port can be used 3 DIP switch options These switches set the pre announcement chime and set the ID number 4 BGM B...

Page 10: ...o the 3 5mm input jack on the rear of the paging microphone as shown in Figure 10 This provides a local source of background music To activate the background music first make sure the Push to Talk PTT...

Page 11: ...hown in figure 11 The messages have to be recordered in MP3 format using any readily available PC software or other means and then transferred to these folders Activating the Voice Over Message Voice...

Page 12: ...ts of the SD Card include a Library folder of sample MP3 files and five folders for the MP3 files associated with the various triggers There should be default MP3 files included in each folder These w...

Page 13: ...e MP3 file NOTE the new MP3 file cannot be Read only To check this right click on the MP3 file and scroll down and select Properties you will get a window that looks like figure 15 Make sure the Read...

Page 14: ...lifier and insert it into your PC Follow the steps on page 11 to open the SD card 3 Extract the contents of the Zip file to the root folder of the SD Card 4 Rename the extracted BIN file to update BIN...

Page 15: ...Pin XLR OUTPUT CONNECTORS Speakers Screw terminals INPUT CONNECTORS Inputs 3 pin XLR balanced or 2 x RCA 24V DC power Screw terminals 240V AC power IEC power connector MUTING PTT via microphone switc...

Page 16: ...r Amplifier The Redback A 4395A is a 500 Watt Mixer amplifier for installations requiring a high power zone amplifier The amplifier has two audio inputs with input 1 either a balanced XLR input or dua...

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