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Atronic A 4275 Operating Manual

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www.altronics.com.au
Operating Manual
A 4275 125W Mixer Amplifier
A 4285 250W Mixer Amplifier

Optional Extras

A 2711 MP3 Module
A 4573 Alert/Evac Board
A 2280B Remote Volume
D 2111 Keyboard USB/PS2
Redback® Proudly Made In Australia
Distributed by Altronic Distributors Pty. Ltd.
Phone: 1300 780 999 Fax: 1300 790 999 Internet: www.altronics.com.au

IMPORTANT NOTE:

Please read these instructions carefully from front to back prior to installation.
They include important setup instructions.
Failure to follow these instructions may prevent the amplifier from working as designed.
User manual revision number: 1.5 29/08/16

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Summary of Contents for Atronic A 4275

  • Page 1: Optional Extras

    Operating Manual A 4275 125W Mixer Amplifier A 4285 250W Mixer Amplifier Optional Extras A 2711 MP3 Module A 4573 Alert/Evac Board A 2280B Remote Volume D 2111 Keyboard USB/PS2 Redback® Proudly Made In Australia Distributed by Altronic Distributors Pty. Ltd.
  • Page 2 REDBACK is a registered trademark of Altronic Distributors Pty Ltd Since 1976 Redback amplifiers have been manufactured in Perth, Western Australia by Altronics. With over 35 years experience in the commercial audio industry, we offer consultants, installers and end users reliable products of high build quality with local product support.

  • Page 3: Table Of Contents

    Contents 1.0 Overview 1.1 Introduction 1.2 Features 1.3 What’s in the box 1.4 Front panel guide 1.5 Rear panel connections 1.6 Led Status Indicators 1.7 Protect Mode 1.8 LCD Status Indicators 1.9 LCD Overview 1.10 Label the input sources, service information and setting up min and max volumes 2.0 Setup 2.1 Setup Guide 2.2 Priorities...

  • Page 4: Overview

    • Optional Alert/Evac tones with voice-over message (via A 4573 module) • Optional MP3 input with remote control (via A 2711 module) 1.3 WHAT’S IN THE BOX A 4275/85 Mixer Amplifier 240V AC IEC C13 Appliance Mains Lead 10A 3 Pin Black Instruction Booklet Redback®...

  • Page 5: Front Panel Guide

    Overview 1.4 FRONT PANEL GUIDE Fig 1.4 shows the layout of the front panel. INPUTS 125W Mixer Ampli er Model : A 4275 Bass Treble Master Volume Music Fault Input Keyboard Power Fig 1.4 Inputs 1-6 volume controls Use these controls to adjust the output volume of inputs 1-6.

  • Page 6: Rear Panel Connections

    Overview 1.5 REAR PANEL CONNECTIONS Fig 1.5 shows the layout of the rear panel. Triggers ALERT - EVAC MODULE DIP 3 DIP 1 Preamp Out CAUTION Priority or VOX muting is only DIP 5 Input 6 Input 5 Input 4 Input 3 Input 2 Input 1...
  • Page 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). Voice Over Volume Use this trimpot adjustment to change the output level of the playback message.

  • Page 8: Output Connections

    Always ensure that the total load of the speakers does not exceed the rated output of the amplifier ie either 4Ω minimum for the 4-16Ω terminals or 80Ω minimum at 100V for the A 4275 (125W) and 40Ω minimum at 100V for the A 4285 (250W).

  • Page 9: Led Status Indicators

    Overview 1.6 LED STATUS INDICATORS There are two led’s on the front panel which indicate when power is available and if there is a fault. The fault led will turn on under the following conditions. Overtemp When the amplifier reaches a dangerous temperature the unit will shutdown, preventing damage. If this occurs, check for short circuits on the speaker line or objects blocking the amplifiers air vents.

  • Page 10: Lcd Overview

    Overview 1.9 LCD OVERVIEW Fig 1.9 shows the layout of the LCD. Voltage Limit Indicator 15 16 If the amplifier goes into an over voltage status this indicator will come on. (see section 1.6 for more details) ZONE LABEL VU Meter SIGNAL C/LIMIT Displays the output of the amplifier in 5dB...

  • Page 11: Label The Input Sources, Service Information And Setting Up Min And Max Volumes

    Overview 1.10 Label the Input Sources, Service Information and setting up Min and Max Volumes A number of options in the A 4275/85 amplifier can be configured through the LCD by connecting a keyboard. • Label Input Sources • Label the Zone •...

  • Page 12: Setup

    2.1 Setup Guide The A 4275 and A 4285 mixer amplifiers have a total of six inputs configurable as either Dual RCA (Line input) or 3 Pin Male XLR (Mic inputs). Each Input includes an individual 4 way dip switch enabling selection of mic or line input operation, adjustable line input sensitivity (100mV or 1V), Priority/VOX muting for inputs 1-3 and phantom power on/off.

  • Page 13: Priorities

    Setup 2.2 Priorities There are 4 levels of priority in the A 4275/85. Level 1 Input 1 has the highest level of priority if the VOX is enabled for this input. (Refer to section 2.3 for DIP switch and VOX sensitivity settings). It will override all other inputs including the optional A 4573 alert/evacuation module (if fitted).

  • Page 14: Dip Switch Settings

    2.3 DIP Switch settings The A 4275/85 range of amplifiers have a set of options which are enabled via the DIP switches 1-5. DIP 1-3 set the input level sensitivity and priorities for inputs 1-6 as outline below and in Fig 2.3A.

  • Page 15: Adjusting Vox Levels

    Setup DIP4 Switch Settings DIP 4 On O Item Fig 2.3B Not Used Not Used Not Used Not Used DIP 4 These are currently not used. DIP 5 This configures the 24V DC switched out status, determines the output of the Preamp Out and sets the phantom power to the inputs.

  • Page 16: Installing The A 4573 Alert/Evac Module

    Setup 2.5 Installing the A 4573 optional Alert/Evac Module The A 4573 module provides a means of adding Alert, Evacuation and chime tones to the amplifier. A voice-over mes- sage can also be recorded and played back during the evacuation tone cycle. All alert and evacuation tones comform to Australian standard AS1607.4.

  • Page 17: Ptt And 24V Dc Switched Out

    Setup 2.6 PTT and 24V DC Switched Output 24V DC is available as a switched output to control external devices like remote volume controls with bypass relays for emergency paging or evacuation strobes (when powered from an external 24V supply). Please note: The 24V DC switched output has a maximum current draw of 1 amp and is internally thermal fuse protected.

  • Page 18: Remote Volume Control

    Setup 2.7 Remote Volume Connection A two way euro block terminal has been provided for the connection of a remote volume control. A potentiometer needs to be wired to these two terminals. **DO NOT LINK OR SHORT THESE TERMINALS** A 1KΩ potentiometer is required for the remote volume to work correctly. The Altronics A 2280B shown below would be suitable.

  • Page 19: Preamp Out, Tape Out, Send And Return

    Setup 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).

  • Page 20: Fitting The Optional A 2711 Mp3 Module

    Setup 2.10 Fitting the Optional A 2711 MP3 Module To install the optional MP3 module, follow these steps. Make sure the amplifier is turned off. Remove the lid from unit. Unscrew the front cover piece from the front panel (keep the screws). Locate the header inside the front of the amplifier.
  • Page 21 Setup A 2711 Controls The MP3 module can be controlled via the supplied remote control or by the buttons on the front of the A 2711. The table below lists the various functions and the means to control them. Keys Explanation Panel Remote...

  • Page 22: Troubleshooting

    Troubleshooting 3.0 TROUBLE SHOOTING If the REDBACK Phase 4 amplifier fails to deliver the rated performance, check the following: No Power, No Lights Make sure amplifier power switch is on. Make sure mains power switch is on at the wall. Check the mains and DC fuse. Replace with only the correct type and rating.

  • Page 23: Specifications

    Power Supply: .....240V AC or 24V DC Line inputs: ....50Hz - 15kHz, -3dB FUSE PROTECTION SENSITIVITY A 4275: .......5A AC , 10A DC Mic inputs: ......3mV balanced A 4285: ......7.5A AC , 20A DC Line inputs:.........100mV-1V Switched 24VDC 1A Internal (both models)
  • Page 24 Warranty 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.

This manual is also suitable for:

A 4285Redback phase 5

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