redback A 4037/43/47 Four Input PA Amplifier Instruction Manual
- June 3, 2024
- redback
Table of Contents
redback A 4037/43/47 Four Input PA Amplifier
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 unit from working as
designed.
REDBACK is a registered trademark of Altronic Distributors Pty Ltd
You may be surprised to learn that Altronics 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.
Our Balcatta production facility manufactures/assembles:
Redback public address products
One-shot speaker & grill combinations
Zip-Rack 19 inch rack frame products
We strive to support local suppliers wherever possible in our supply chain,
helping to support Australia’s manufacturing industry.
Redback Audio Products
100% developed, designed & assembled in Australia.
Since 1976 we have been manufacturing Redback amplifiers in Perth, Western
Australia. 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. We believe there is significant added
value for customers when purchasing an Australian made Redback amplifier or PA
product.
Local support & feedback.
Our best product features come as a direct result of feedback from our
customers, and when you call us, you speak to a real person – no recorded
messages, call centres or automated push button options.
It’s not only the assembly team at Altronics who are employed as a direct
result of your purchase, but hundreds more at local companies used in the
supply chain.
Industry-leading 10 year warranty.
There’s a reason we have the industry leading DECADE warranty. It’s because of
a long tried and tested history of bulletproof reliability. We’ve heard PA
contractors tell us they still see the original Redford amplifier still in
service in schools.
We offer this comprehensive parts & labour warranty on almost every Australian
Made Redback public address product.
This offers both installers and end users peace of mind that they will receive
prompt local servicing in the rare event of any problems.
OVERVIEW
The Redback A 4037 40 Watt, A 4043 60 Watt and A 4047 100 Watt 4 channel mixer amplifiers are specifically designed for applications requiring up to three microphone inputs, without compromising output power and overall performance.
The amplifiers feature three inputs which can be configured for either
microphone or line level operation.
The A 4037 conservatively delivers 40W RMS power, while the A 4043 delivers
60W RMS and the A 4047 delivers 100W RMS. Frequency response extends from 50Hz
to 15kHz ±3dB at a total harmonic distortion (THD) of less than 0.5% @ 1kHz.
Vox muting is provided on inputs one and two, which, when activated,
automatically mutes the other inputs. Bass and treble controls and phantom
powering capability enable unparalleled flexibility for a wide scope of
applications such as factories, workshops, mine sites, sports clubs and office
buildings.
The amplifiers operate from 240V AC mains or 24V DC permitting battery backup
operation during mains power failure.
The output comes standard suitable for a 100V line load, but this can be
configured internally to 70V line or low impedance (4 – 16Ω) loads.
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 mode which enables the
amplifier to continue to run at a reduced output level if it is being over
driven.
Tape output sockets are provided for recording purposes or feeding into
additional power amplifiers.
Remote volume available when A 4373 Digital volume control module fitted
internally and external A 2280B wall plate or 1KΩ potentiometer connected.
Alert and Evacuation tones (conforming to AS1607.4) along with chime tones and
voice over message option available when optional A 4573 fitted.
FEATURES
- 3 Balanced microphone inputs / 3 Aux inputs / 1 Music input
- Robust design incorporating latest Mosfet technology
- Very Low noise and distortion
- 100V standard with optional 70V and 4-16Ω outputs
- 240V AC or 24V DC operation
- VOX muting on inputs 1 and 2 (Switch selectable internally)
- Adjustable VOX level sensitivities
- Bass and Treble controls
- Tape Output
- Phantom power on microphone inputs (DIP switch selectable internally)
- Multi stage thermally cued fan cooling
- Output Peak Limited
- Thermal Overload protected
- Signal Presence Indicator
- Half power mode when overdriven
- Fault Indicators
- 24V DC Power Status Indicator
- Optional Alert/Evac module with voice over message for emergency tones (A 4573)
- Optional remote volume (With A 4373 Digital volume control module fitted and external A 2280B wall plate)
- Rack Mountable (suits 19 inch racks) with optional A 4376 rack ears
Figure 1 shows the layout of the front panel
-
Inputs 1-4 volume controls
Use these controls to adjust the output volume of inputs 1-4 (volume 3 is used to adjust the volume of input 4 the music input. -
Master volume Control
Use this control to adjust the master volume. -
Bass and Treble Controls
Use these controls to adjust the bass and treble. -
OverTemp/ Half Power Indicator
When this LED is red it indicates when the amplifier is overheating. The output will be disconnected until the amplifier is once again cool enough to operate. If this LED is orange the amplifier has gone into half power mode.
This mode lets the amplifier continue to run at a lower output rather than shutdown completely. This mode might be initiated from the amplifier being overdriven or overloaded. -
Power Switch
Use this to turn the unit on. -
On Indicator
This led indicates the unit has power. -
24V DC Indicator
This LED indicates when the amplifier is being powered from the 24V input. -
Fault Indicator
This led indicates when the amplifier has a fault. -
Peak Limit Indicator
This LED indicates when the input signal is clipping. -
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 reduced. -
Protect Indicator
This LED indicates when the amplifier module has an internal circuitry fault. -
Signal Presence Indicator
This LED indicates when an input signal is present. -
Music Input
Use this input to connect a portable music player. This input over-rides the rear input 3 and is adjusted via the
volume 3 pot. -
Vox level controls
Use these controls to adjust the vox sensitivities of inputs 1-2.
Figure 2 shows the layout of the rear panel.
-
240V AC power socket (Australian standard)
Connects to 240V AC mains power with the included IEC lead. The internal fuse is an M205 1 Amp for the
A 4037 40 Watt amplifier, M205 2 Amp for the A 4043 60 Watt amplifier and an M205 4 Amp for the A 4047
100 Watt amplifier. -
Output Connections
Speakers fitted with a 100V line transformer may be connected to these terminals. Always ensure that the total load of the speakers does not exceed the rated output of the amplifier i.e. 250Ω minimum at 100V for 40W,166Ω minimum at 100V for 60 Watts and 100Ω minimum at 100V for 100 Watts. Otherwise either the DC or
mains fuse could blow or the fault led activate and the amp will shut down. Always be careful to avoid short circuits and connection to the wrong terminals. -
Optional Alert/Evacuation Tone Generator with Voice Over Message
When fitted this card provides standard Alert and Evacuation tones which conform to AS1607.4. A voice over message can be recorded to the card and various chime tones are included. -
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 internally mixed to produce a mono input signal. -
Tape Out
Dual RCA’s provided for recording purposes. This is a line level output. -
Optional Plugin
This connection is to be used when the optional A 4373 Digital Volume Board if fitted inside the amplifer. This
provides remote volume when used in conjunction with a 1K potentiometer wired to these terminals.
7 24VDC IN
Battery Backup: Provision has been provided to run the amplifier from a suitably rated 24V battery system in the
event of a mains failure. Using appropriately rated cable, connect the battery to the “24V DC In” terminals.
Observe correct polarity when connecting. (see Fig 5 for more details)
8 DC fuses
This fuse protects the internal power supply. If the resettable fuse is tripped in the 60W and 100W models it
is easily reset by pressing the small button on the fuse. If the fuse blows in the 40W model it will need to be
replaced.
SPEAKER CONNECTIONS
Speakers fitted with 100V line transformers may be connected to the output terminals on the rear of the amplifer. Always ensure the total load of the fitted speakers does not exceed the rated output of the amplifier (ie 40 watts for the A 4037 60 watts for the A 4043 and 100 watts for the A 4047 amplifier) otherwise damage may result. When fitting speakers with line transformers the impedance of the load cannot be measured using a standard multimeter. An impedance meter is required. Fig 3 lists the impedance at certain loads of speakers fitted with 70V and 100V line transformers. So for a total load of 40 watts using 100V line transformer fitted speakers, the impedance of the speaker load should be 250Ω.
AUDIO CONNECTIONS
The amplifier has three balanced XLR audio inputs, three dual RCA line inputs
which are internally mixed to create mono signals and a front mounted Music
Input for portable devices. This input when connected,over-rides the rear
channel 3 audio sources and is adjusted via the volume 3 level control. A VOX
function is also included which when enabled will allow input 1 to mute inputs
2 and 3, or input 2 to mute input 3. The VOX circuitry is selected by internal
switches as shown in figure 5. The VOX1 switch when set to ON will allow input
1 to mute inputs 2 & 3. The VOX2 switch when set to ON will allow input 2 to
mute input 3. The VOX sensitivity is adjusted by the trimpots located on the
front of the amplifier.
Fig 4 shows a typical install where the A 4037 has a balanced microphone connected to input 1 and a Line level source connected to input 2. If the VOX1 switch is set to “ON”, the microphone will VOX mute the CD player connected to input 2.
PHANTOM POWER
All three microphone 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 unit and then
remove the lid. The location of the DIP switches is shown in figure 5.
The Phantom power DIP switch settings are:
- DIP 1 enables the phantom power to the XLR connector on input 1.
- DIP 2 enables the phantom power to the XLR connector on input 2.
- DIP 3 enables the phantom power to the XLR connector on input 3.
- DIP 4 is not used.
VOX MUTING
Vox muting is provided on inputs one and two, which, when activated,
automatically mutes the other inputs.
The VOX1 switch when set to ON will allow input 1 to mute inputs 2 & 3. The
VOX2 switch when set to ON will allow input 2 to mute input 3.
The VOX sensitivity is adjusted by the trimpots located on the front of the
amplifier (see figure 1).
REMOTE VOLUME (Optional)
It is possible to control the master volume with the addition of the A 4373
Digital Remote volume board and a 1kΩ potentiometer (or Altronics A 2280B wall
plate) fitted across the terminals labelled “Optional Plugin” on the rear of
the amplifier. The plugin board is fitted inside the amplifier in the location
shown in figure 5.
NOTE: Take special care with the orientation of the board and remove
power from the amplifier before fitting.
POWER SUPPLY
The amplifier operates on 230V AC or primarily for battery backup operation a
24V DC supply. Ensure power is switched OFF at the front panel before
connecting either mains power to the IEC socket or 24V DC to the screw
terminal input. As high currents may be drawn when operating from a 24V DC
supply confirm the capacity of the DC power supply used.
TROUBLESHOOTING
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.
100V line). Check for any short circuits on the speaker line.
Very Low Output Volume
Make sure that the input is the correct level (check for shorted connectors).
Check for any short circuits on the speaker line.
Check if signal LED on the front panel is lit to indicate there is signal. If
it is not lit there is no signal present.
Continually Blows Fuses
Make sure that the speaker line is not shorted. Check speaker types, ratings
and if on correct output.
Amplifier Keeps on Cutting In & Out
Make sure that there is adequate ventilation around the amplifier. Check the
vent slots on the front,top and sides are not covered or blocked and the fan
on the rear is functioning correctly. Check also speaker types, ratings and
for any short circuits on the speaker line.
SPECIFICATIONS
POWER OUTPUTS
-
Power: …………………………………… A 4037 – 40 Watts RMS
………………………………….. A 4043 – 60 Watts RMS
………………………………… A 4047 – 100 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: ……………………. 40W – 1A AC ,4A DC
……………………. 60W – 2A AC ,5A DC
……………….. 100W – 4A AC ,7.5A DC -
DIMENSIONS ……………………………..≈483W x 250D 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.
Redback® Proudly Made In Australia
www.redbackaudio.com.au