Designed in conjunction with Australia’s leading PA professionals to cater for the needs of multi-source installations. This redesigned unit offers the ability to monitor amplifier status via the colour LCD screen, plus custom labelling of inputs. The A 2711 optional USB & SD card module provides music playback when fitted.

Engineered for professional PA installations, the A 4275C conservatively delivers 125W RMS power. Frequency response extends from 50Hz to 15kHz ±3dB at a total harmonic distortion (THD) of less than 0.5% @ 1kHz. Voice/Vox muting, including three levels of input priority, bass and treble controls and phantom powering capability enable unparalleled flexibility for a wide scope of applications such as schools, shopping centres, workshops, mine sites and office buildings. Operates from 240V ac mains or 24V dc permitting battery backup operation during mains power failure. Output can be 100V line, 70V line or low impedance (4 - 16 Ohm) loads. The circuit includes thermal overload shutdown, over current and overload protection plus fuses on both ac and dc supply rails.

LCD: Indicates input and output levels, amplifier status; including heatsink temperature, overload and over current conditions. 240V ac or 24V dc operation. Also allows custom labelling of input sources via USB keyboard.

Input configuration: Each input can be configured for either balanced microphone or line use. A dip switch is supplied for each input providing the following features: Phantom power on/off, Mic or line, 100mV or 1V, Vox muting on/off (priority)

Three levels of priority: Priority selection is by a dip switch on the rear panel: Input 1 over 2-6, input 2 over 3-6 and input 3 over 4-6.

Overload protection: In the event of an overload, the output current is limited by the internal circuitry, thus reducing the output voltage at the speaker terminals.

Input Limiting: Limits the output to 110V regardless of input level. This prevents dangerously high voltages from damaging the loudspeaker.

A 4573 Alert/evac option board: Generates pre chime, bell, alert and evacuation tones. The alert tone can function continuously, or switch to evac tone after a preset time delay (adjustable 30 seconds to 4.5 minutes). Simply connects to the amplifier internally via the cable provided.

A 2280B Remote volume wall plate: Connects via figure 8 cable to the “remote volume” terminals of the amplifier. Enabling overall volume to be adjusted as required. Features a PCB jumper to reverse the volume control direction. Maximum cable length 100m.

Features

• Very low noise and distortion
• Thermal overload protection
• Thermally cued forced fan cooling
• Protect Mode
• 4 levels of priority/Vox muting
• LCD display of amplifier status
• Minimum and Maximum Master Volume Over-ride
• Minimum and Maximum Remote Volume Over-ride
• USB keyboard interface for labelling of inputs and installer contact details. • 6 inputs configurable as balanced microphone or line
• Music Input on front panel
• Adjustable line level sensitivity
• 70V, 100V and 4-16ohm outputs
• 240V AC or 24V DC operation
• 300mA Backup Battery charging
• Phantom power (on microphone inputs)
• Tape out (Dual RCA)
• Pre-amp send and return connections (RCA)
• Balanced line output (3 pin male XLR)
• Remote Volume option
• 24V switched output via PTT microphone (not supplied)
• 19” Rack Mount (2 unit).
• Optional Alert/Evac tones with voice-over message (via A 4573 module)
• Optional MP3 input with remote control (via A 2711 module)

100% developed, designed & assembled in Australia.
Since 1974 Redback PA products have been manufactured in Perth, Western Australia by Altronics. With over 50 years experience in the commercial audio industry, we offer consultants, installers and end users reliable products of high build quality with local product support. Read more about our Australian Made products

Backed by an industry leading 10 Year Manufacturer Warranty.
Our Redback products have a long tried and tested history of bulletproof reliability. Altronics offers a 10 Year Warranty on all Australian Made Redback products. Our local in-house service department has all the know how to answer technical queries and provide timely service. Read more about our industry leading warranty.

• Altronics Code: A4275C
• I/N: 17555
• Barcode: 9321758246733
• Shipping Weight: 13.00000Kg
• Packaging Sizes
• EACH: 1
• Printed Catalogue Page 49
• Large Image 1
• Large Image 2
• Brochure
• Instructions

• Power Outputs
• 125 watts RMS
• Distortion: < 0.5%, @ 1kHz
• Output line: 70V, 100V or 4 - 16Ω
• Line output: 600 Ohm balanced, 0dBV
• Frequency Response
• Mic inputs: 50Hz - 12kHz, -3dB
• Line inputs: 50Hz - 15kHz, -3dB
• Sensitivity
• Mic inputs: 3mV balanced
• Line inputs: 100mV-1V
• Signal To Noise Ratio (Limiting by-passed)
• Mic inputs: > 75dB below rated output
• Line inputs: > 81dB below rated output
• Output Connectors
• Speakers: Screw terminals
• Line out: 3 pin XLR, Tape out RCA / send & return RCA
• 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 or VOX muting
• Controls
• Mic inputs: Volume
• Line inputs: Volume
• Bass: ±10dB @ 100Hz
• Treble: ±10dB @ 10kHz
• Master: Volume
• Power: On/off switch
• Indicators: Power, fault, all other indicators on LCD
• Power Supply: 240V AC or 24V DC
• General
• Weight: ≈14.5kg
• Colour: Black
• Fuse Protection: 5A AC , 10A DC
• Dimensions: ≈483W x 330D x 88H

*Specifications are subject to change without notice.