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Redback® A 4275B/85B 125/250W Mixer Amplier

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Redback® A 4275C/85C 125/250W Mixer Amplier

User manual revision number: 1.1 12/08/2022

Operating Manual

A 4275C 125W Mixer Amplier

A 4285C 250W Mixer Amplier

Redback® Proudly Made In Australia

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 amplier from working as designed.

Optional Extras

A 2280B Remote VolumeA 2711 MP3 Module A 4573 Alert/Evac Board D 2111 Keyboard USB/PS2

Summary of content (24 pages)

PAGE 1
Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Operating Manual A 4275C 125W Mixer Amplifier A 4285C 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 IMPORTANT NOTE: Please read these instructions carefully from front to back prior to installation. They include important setup instructions.
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Redback® A 4275C/85C 125/250W Mixer Amplifier You may be surprised to learn that Redback is still manufacturing hundreds of product lines right here in Australia. We have resisted the move offshore by offering our customers better quality products with innovations to save them time and money.
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Contents Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® 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 4 4 4 5 6 8 8 8 8 10 2.0 Setup 2.1 Setup Guide 2.2 Priorities 2.3 DIP Switch Settings 2.4 Adjusting VOX levels 2.
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Redback® A 4275C/85C 125/250W Mixer Amplifier Overview 1.0 OVERVIEW 1.1 INTRODUCTION The REDBACK range of mixer amplifiers are engineered to a very high standard and are packed with a host of features to satisfy a large range of installations. 1.
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Overview 1.4 FRONT PANEL GUIDE Fig 1.4 shows the layout of the front panel. 1 2 3 INPUTS 4 6 4 8 2 0 4 8 0 10 4 4 0 6 8 2 8 Vox 0 10 Model : A 4275C 8 0 10 4 6 0 10 Bass Treble Master Volume 5 6 2 125W Mixer Ampliﬁer 6 2 Vox 10 3 1 2 6 2 Vox 8 2 10 Music Input Fault _ _ + On + Power 6 4 Keyboard 11 10 9 8 7 6 5 4 Fig 1.
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Redback® A 4275C/85C 125/250W Mixer Amplifier Overview 1.5 REAR PANEL CONNECTIONS Fig 1.5 shows the layout of the rear panel.
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Overview 7 Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Input connectors There are 6 sets of inputs which can be either balanced mic or line inputs. The line inputs are dual RCA connectors which are internally mixed to produce a mono input signal. DIP SW 1-3 Inputs 1-6 include an individual 4 way dip switch enabling adjustable input sensitivity (100mV or 1V) and Priority/ VOX muting for inputs 1-3. Priority/VOX muting is not available on inputs 4-6.
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Redback® A 4275C/85C 125/250W Mixer Amplifier 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. 1.
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Overview 1 15 16 1 SIGNAL 2 3 4 5 ZONE LABEL 100% 80% V/LIMIT 7 0dB -5dB H/SINK TEMP PROTECT MODE CURRENT LIMIT EMERG TONES 70% 60% 50% -10dB -15dB 30% 20% 10% 32 -25dB -30dB -35dB -40dB 30 SERVICING/INSTALLER LABEL 11 8 -20dB INPUTS 1) INPUT 1 1) INPUT 2 1) INPUT 3 1) INPUT 4 1) INPUT 5 1) INPUT 6 40% 12 6 MAINS ON 24VDC ON 90% 13 C/LIMIT 9 10 Fig 1.
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Redback® A 4275C/85C 125/250W Mixer Amplifier Overview 1.10 Label the Input Sources, Service Information and setting up Min and Max Volumes A number of options in the A 4275C/85C amplifier can be configured through the LCD by connecting a keyboard.
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Setup 2.0 SETUP 2.1 Setup Guide The A 4275C and A 4285C 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. (Priority/ VOX muting is not available on inputs 4-6).
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Redback® A 4275C/85C 125/250W Mixer Amplifier Setup 2.2 Priorities There are 4 levels of priority in the A 4275C/85C. 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). This input could be used for emergency microphone paging or telephone pag ing etc.
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Setup 2.3 DIP Switch settings The A 4275C/85C 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. (* Priority/VOX muting is only available for inputs 1-3. Inputs 4-6 have no priority levels.) DIP 1 Switch 1 - Sets Input 2 RCA input sensitivity to either 1V or 100mV.
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Redback® A 4275C/85C 125/250W Mixer Amplifier Setup DIP4 Switch Settings DIP 4 SW 1 2 3 4 Item On Oﬀ Not Used Fig 2.3B 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. See Fig 2.3C for details. Switch 1- Sets the switched 24V DC out to ON or OFF.
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® 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 message can also be recorded and played back during the evacuation tone cycle. All alert and evacuation tones comform to Australian standard AS1607.4. NOTE: If the Alert/Evac Tone Module (A 4573) is fitted its VOX will always be enabled.
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Redback® A 4275C/85C 125/250W Mixer Amplifier 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. Fig 2.6 demonstrates the connection of a strobe to the 24V DC output.
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® 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 Redback A 2280B shown below would be suitable. The maximum distance from the amplifier the potentiometer can be connected is 100 metres.
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Redback® A 4275C/85C 125/250W Mixer Amplifier 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). Factory default setting disables the preout. (Refer to section 2.3 DIP switch settings).
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Setup 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 batteries 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.
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Redback® A 4275C/85C 125/250W Mixer Amplifier Setup 2.10 Fitting the Optional A 2711 MP3 Module To install the optional MP3 module, follow these steps. 1. 2. 3. 4. 5. 6. 7. 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. See Fig 2.
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Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® Setup A 2711 Controls The A 2711 MP3 module can be controlled via the supplied remote control or by the buttons on the front of the unit. The table below lists the various functions and the means to control them. Keys Panel Remote PLAY/ PAUSE When this key is pushed during USB/SD stop, play will start after track search. When this key is pushed during USB/SD is playing, then it is changed to pause.
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Redback® A 4275C/85C 125/250W Mixer Amplifier 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. Over rated fuses with invalidate warranty. Distorted Output Check that the speaker type is correct for the output that you are using (ie.
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Specifications Redback® AA 4275C/85C 4275B/85B 125/250W Mixer Amplifier Redback® 4.0 SPECIFICATIONS CONTROLS POWER OUTPUTS Mic inputs:....................50Hz - 12kHz, -3dB Line inputs: ..................50Hz - 15kHz, -3dB Mic inputs: .......................................Volume Line inputs:......................................Volume Bass:..................................±10dB @ 100Hz Treble:................................±10dB @ 10kHz Master: .............................................
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Redback® A 4275C/85C 125/250W Mixer Amplifier 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. 24 Redback® Proudly Made In Australia www.redbackaudio.com.