$915.00 per ea

Quantity Price
ea $915.00
2+ $829.00
per ea
All prices shown are (inc. GST)


An evolution of our PA mixer series, the A 4427 combines 8 channels of audio with an MP3 based tone generator for alert, evacuation, chime and pre-recorded voice over message alerts. Six audio channels can be selectable for either balanced mic or line. These are connected via stereo RCA (line) or pluggable screw terminals (balanced). Two audio channels are dedicated RCA inputs, plus a 3.5mm jack input on the front panel for connection to local audio/music sources.

Tone Generator Operation.
Tones, chimes and pre-recorded messages are played from the micro SD card which plugs into the rear panel of the mixer. Individual level controls are provided for alert/evac, chime and voice over. All of these can be triggered by closing contacts such as switches, from Fire Indicator Boards (FIB) or any other remote contact source.

Adjustable Input Sensitivities.
On the rear panel a DIP switch allows selection of input sensitivity between 3mV, 100mV and 1V, plus phantom power and VOX muting options for each of the inputs.

The mixer is powered by 24V DC and is provided with a 2.1mm DC jack input and a back up 24V DC power source via screw terminal block for use when mains power fails. A 24V DC output is provided (limited to 120mA current draw) which activates when any of the Alert, Evacuation or Chime triggers are operated. It also activates when VOX circuits or any of the PTT muting is activated.

Box Contents
A 4427 Mixer 8 Channel with MP3 active indicator
24V 1A DC Plugpack
Instruction Booklet


  • Eight input channels
  • Micro SD card message player for audio announcements
  • Individual level, bass and treble control on all inputs
  • Six levels of VOX priority
  • Adjustable VOX sensitivity
  • 3.5mm music input
  • Adjustable input sensitivity on line inputs
  • 24V DC battery back up terminals
  • In built Alert/Evac/Chime functionality
  • 24V DC output
  • MP3 active indicator
  • LED VU meter
  • 10 Year Warranty
  • Australian Designed and Manufactured

100% developed, designed & assembled in Australia.
Since 1976 Redback PA products have been manufactured in Perth, Western Australia by Altronics. With over 40 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.

Information & Downloads


  • Output Level: 0dBm
  • Distortion:0.01%
  • Frequency Response: 140Hz - 20kHz
  • Sensitivity:
  • Mic inputs: 3mV balanced
  • Line inputs: 100mV-1V
  • Output Connectors:
  • Line out: 3 pin XLR balanced or 2 x RCA
  • Switched out: Screw terminals
  • Input Connectors:
  • Inputs: 3 pin XLR balanced or 2 x RCA, 3.5mm stereo jack front panel
  • 24V DC power: Screw terminals
  • 24V DC Power: 2.1mm DC Jack
  • Remote triggers: Screw Terminals
  • Controls:
  • Power: Standby Switch
  • Bass: ±10dB @ 100Hz
  • Treble: ±10dB @ 10kHz
  • Master: Volume
  • Inputs 1-4: Volume
  • Indicators:Power on, MP3 error, MP3 active, Signal Present, VU Meter
  • General:
  • Power Supply: 24V DC
  • Dimensions: 482W x 175D x 44H
  • Weight: 2.1kg
  • Colour: Black
    • *Specifications are subject to change without notice.

Warranty & Returns


We offer 10 years warranty on this product from its date of purchase. This is available from Altronics stores, online purchases or Altronics resellers. In accordance with our full warranty terms we will repair, replace or refund if goods you have purchased from us are defective.


Not withstanding our warranty policy, if you are dissatisfied with our goods or service you may return the goods within 14 days of our despatch date. Simply contact us for a return authorisation number and we will refund your purchase in full, less transport costs on receipt of goods. All returned goods must be in as sold condition including all packaging, instructions, invoices etc.