Redback PHASE 5 A 4395A User manual

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.au Redback® Proudly Made In Australia 1
Operating Manual
A 4395A 500 Watt Mixer Amplier
User manual revision number: 1.0 22/09/2021
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.

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.auRedback® Proudly Made In Australia
2
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 ampliers 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 signicant added value for customers when purchasing an Australian made
Redback amplier 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.
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 bullet-
proof reliability. We’ve heard PA contractors tell us they still see the original Redford amplier 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.
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.
It’s not only the assembly team at Redback who are employed as adirect result of your purchase, but hundreds more at
local companies used in the supply chain.

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.au Redback® Proudly Made In Australia 3
OVERVIEW
The Redback A 4395A is a 500 Watt Mixer amplier for installations requiring a high power zone amplier. Ideally suited
for use in shopping centres, pedestrian precincts, public transport facilities and convention centres.
The amplier has two audio inputs, with input 1 either a balanced XLR input or dual RCA line input, and input 2 a dual
RCA. There is also a music input on the front of the amplier for connection of portable devices. This input when
connected, over-rides the rear input 2 audio source and is adjusted via the volume 2 level control.
A VOX circuit with front panel sensitivity adjustment, allows input 1 to mute input 2. Phantom power (15 volts) is available
at the 3 pin XLR on input 1 and both inputs 1 and 2 have adjustable input sensitivies.
The amplier has a host of protection circuitry including over current, over voltage and short circuit protection.
FEATURES
• Robust design incorporating latest Mosfet technology
• Very Low noise and distortion
• 70V, 100V and 4-16Ω outputs
• 240V AC or 24V DC operation
• 24V DC @ 1 Amp output for external devices
• 300mA battery trickle charge
• Adjustable input level sensitivities
• Bass and Treble controls
• Phantom power on microphone input (XLR Input 1)
• Multi stage thermally cued fan cooling
• Output Peak Limited
• Thermal Overload protected
• Signal Presence Indicators
• Fault Indicators
• Power Status Indicators
• Rack Mountable (suits 19 inch racks)

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.auRedback® Proudly Made In Australia
4
Fig 1 shows the layout of the front panel.
Fig 1
1 Input 1 volume control
Use this control to adjust the output volume of input 1.
2 Vox level control
Use this control to adjust the vox sensitivity of input 1.
3 Input 2 volume control
Use this control to adjust the output volume of input 2.
4 Music Input
Use this input to connect a portable music player. This input over-rides the rear input 2 and is adjusted via the
volume 2 control.
5 Bass and Treble Controls
Use these controls to adjust the bass and treble.
6 Signal Presence Indicator
This LED indicates when an input signal is present.
7 Peak Limit Indicator
This LED indicates when the input signal is clipping.
8 VOX Active Indicator
This led indicates when the VOX muting is active.
9 Over Temp Indicator
This LED indicates when the amplier is overheating. The output will be disconnected until the amplier is once
again cool enough to operate.
10 Current Limit Indicator
This LED indicates when the output is drawing too much current from the amplier. The output will be
disconnected until the current draw is reduced.
11 Shut Down Indicator
This LED indicates when the amplier has an over temp occurrence or if the internal circuitry has a fault.
12 24V DC Indicator
This LED indicates when the amplier is being powered from the 24V input.
13 Mains Indicator
This LED indicates when the amplier is being powered from the mains (230V AC).
14 On Indicator
This LED indicates the unit has power.
15 Power Switch
Use this to turn the unit on.
15
0
2
46
8
10
0
2
46
8
10
1 2
34 5 6 7 8 9 10 11 12 13 14
Mains On Power 24V DC
Power StatusSignal Status
Present
Fault Status
Over
Limit Limit
Current
Temp
Peak
Down
Shut
Model : A 4395A
500W Public Address Mixer
TrebleBass
Music
Input
VOX
Sens.
Volume 1
Volume 2
Active
VOX

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.au Redback® Proudly Made In Australia 5
Fig 2 shows the layout of the rear panel.
Fig 2
1 Output Connections
Speakers with total impedance of 4 to 16 ohms, or speakers tted with a 70V/100V line transformer may be
connected. Always ensure that the total load of the speakers does not exceed the rated output of the amplier
ie either 4Ω minimum for the 4-16Ω terminals or 20Ω minimum at 100V for 500W. 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.
2 24V 1A output
A constant 24V output terminal has been provided to power ancilliary 24V devices.
3 DC Resettable fuses
These fuses protect the internal power supply. If the fuses are tripped they are easily reset by pressing the small
buttons on the fuses.
4 24V Backup battery charging
The A 4395A amplier includes a charging circuit so that a backup battery connected to the ampliers 24V DC
Input can be trickle charged. The battery charger is connected to the battery internally when the link is tted to
this connector (see Fig 5 for more details). The battery will be charged at approximately 300mA.
5 24VDC IN
Battery Backup: Provision has been provided to run the amplier 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)
6 Input 1
This input can be either a balanced XLR input or dual RCA line input with adjustable input sensitivities of 100mV
or 1V. The line input dual RCA connectors are internally mixed to produce a mono input signal.
7 Input 2
This input is a dual RCA line input with adjustable input sensitivities of 100mV or 1V. The line input dual RCA
connector is internally mixed to produce a mono input signal.
8 DIP Switches
These DIP switches set the input sensitivities of inputs 1 & 2, enable the VOX muting and enable the phantom
power to the XLR input (see Fig 6 for more detail).
4 -16Ω
70V
230V AC @ 50Hz
(Fuse 10A M205)
100V
12
3
1 • Shield
2 • Hot
3 • Cold
Input 1
Made in Australia by
Altronic Distributors Pty Ltd
www.altronics.com.au
INPUT
24V DC
+
–
RISK OF ELECTRIC SHOCK
OPEN BY QUALIFIED
PERSONNEL ONLY !
CAUTION
OUTPUTS
+
–
+
–
+
–
+_
24V DC
OUT
(1A Max)
LINK TO
CHARGE
BACKUP
BATTERY
RESETTABLE
FUSE 20 AMP
RESETTABLE
FUSE 20 AMP Input 2
Balanced Mic
Line
L
L R
R
Line
DIP Switches
1 2 3 4
DIP Switch Settings
SW Item On O
1
2
Input 1 Sensitivity 1V
3
VOX Enable
4
0.1V
Phantom Power Mic
Input 2 Sensitivity 1V 0.1V
On O
On O
Balanced
Mic Wiring
1 2 3 4
2 1
3
1234567 8

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.auRedback® Proudly Made In Australia
6
SPEAKER CONNECTIONS
Speakers with a total impedance or 4-16Ω may be connected to the terminals marked 4-16Ω on the rear of the amplifier.
Speakers fitted with line transformers (either 70V or 100V) may be connected to the corresponding 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 500 watts) 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 500 watts using 100V line transformer
fitted speakers, the impedance of the speaker load should be 20Ω.
Fig 3
AUDIO CONNECTIONS
The amplier has two audio inputs, with input 1 either a balanced XLR input or dual RCA line input which is internally
mixed to create a mono signal. Input 2 is a dual RCA which is internally mixed to create a mono signal. Both inputs have
adjustable input sensitivities of 100mV or 1V set by the DIP switches on the rear of the unit.
A music input on the front of the amplier is also provided for connection of portable devices. This input when
connected, over-rides the rear input 2 audio source and is adjusted via the volume 2 level control.
A VOX function is also included which when enabled will allow input 1 to mute input 2.
Fig 4 shows a typical install where the A 4395A has a balanced microphone connected to input 1 and a Line level source
connected to input 2. If DIP switch 2 is set to “ON”, the microphone will VOX mute the CD player connected to input 2.
Fig 4
i
Wiring speakers in parallel for 70/100V line: Where several speakers are to
be used at one time, on one circuit, it becomes necessary to use speakers fitted
with line-matching transformers. This is to overcome the effects of connecting
speakers in parallel and cable losses. The amplifier generally has an output
voltage of 100 volts (70 volts is typically used in North America, however
operation is similar). In this configuration the total wattage load on the amplifier
is derived from adding all the line transformer primary tap ratings together. For
example, 70 one watt speakers will have a total speaker load of 70 watts. Or
alternatively, it is conceivable to connect 100 one watt speakers to a 100 watt,
100 volt line amplifier.
Measuring 70/100V Line Speaker Impedance: To measure amplifier system
load, you must use an impedance meter in order to measure the ac resistance
of the connected speaker network. Impedance cannot be measured with a
standard multimeter, as this measures the dc resistance.
About 70V & 100V Line Speaker Systems
Load 70V 100V
0.5W 9.4kΩ 20kΩ
0.66W 7.12kΩ 15kΩ
1W 4.7kΩ 10kΩ
1.25W 3.76kΩ 8kΩ
2W 2.35kΩ 5kΩ
2.5W 1.88kΩ 4kΩ
3W 1.56kΩ 3.3kΩ
5W 940Ω 2kΩ
7.5W 626Ω 1.3kΩ
10W 470Ω 1kΩ
15W 313Ω 666Ω
20W 235Ω 500Ω
30W 156Ω 333Ω
40W 117Ω 250Ω
60W 78Ω 166Ω
100W 47Ω 100Ω
125W 37Ω 80Ω
250W 19Ω 40Ω
500W 9.4Ω 20Ω
Redback Q 2004
Speakers tted with
100V line transformers.
4 -16Ω
70V
230V AC @ 50Hz
(Fuse 10A M205)
100V
12
3
1 • Shield
2 • Hot
3 • Cold
Input 1
Made in Australia by
Altronic Distributors Pty Ltd
www.altronics.com.au
INPUT
24V DC
+
–
RISK OF ELECTRIC SHOCK
OPEN BY QUALIFIED
PERSONNEL ONLY !
CAUTION
OUTPUTS
+
–
+
–
+
–
+_
24V DC
OUT
(1A Max)
LINK TO
CHARGE
BACKUP
BATTERY
RESETTABLE
FUSE 20 AMP
RESETTABLE
FUSE 20 AMP Input 2
Balanced Mic
Line
L
L R
R
Line
DIP Switches
1 2 3 4
DIP Switch Settings
SW Item On O
1
2
Input 1 Sensitivity 1V
3
VOX Enable
4
0.1V
Phantom Power Mic
Input 2 Sensitivity 1V 0.1V
On O
On O
Balanced
Mic Wiring
1 2 3 4
2 1
3
CD
REDBACK

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.au Redback® Proudly Made In Australia 7
POWER SUPPLY
The amplier operates on 230V AC or 24V DC primarily for battery backup operation. 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 conrm the capacity of the DC power supply used.
24V DC OUTPUT
A constant 24V output terminal has been provided to power ancilliary 24V devices. The output has a maximum current
draw of 1 amp. If more than 1 amp is drawn from the output, internal polyswitches will disconnect the output. These will
reset once the current draw is reduced.
24V BACKUP BATTERY CHARGING
The A 4395A amplier includes a charging circuit so that a backup battery connected to the ampliers 24V DC Input can
be trickle charged. The battery charger is connected to the battery internally when the link is tted to the charging link
connector (see Fig 5 for more details). The battery will be charged at approximately 300mA.
Fig 5
DIP Switch settings
The A 4395A amplier has a set of options which are enabled via the DIP switches 1-4. See Fig 6.
DIP 1 sets the input level sensitivity for input 1 (either the balanced 3 pin XLR or Dual RCA’s).
DIP 2 enables the VOX muting. When the VOX is active input 1 will mute input 2.
DIP 3 enables the phantom power to the XLR connector on input 1.
DIP 4 sets the input level sensitivity for input 2.
Fig 6
Speakers tted with
100V line transformers.
LINK THESE TERMINALS
TO CHARGE BACKUP BATTERY
+-
4 -16Ω
70V
230V AC @ 50Hz
(Fuse 10A M205)
100V
12
3
1 • Shield
2 • Hot
3 • Cold
Input 1
Made in Australia by
Altronic Distributors Pty Ltd
www.altronics.com.au
INPUT
24V DC
+
–
RISK OF ELECTRIC SHOCK
OPEN BY QUALIFIED
PERSONNEL ONLY !
CAUTION
OUTPUTS
+
–
+
–
+
–
+_
24V DC
OUT
(1A Max)
LINK TO
CHARGE
BACKUP
BATTERY
RESETTABLE
FUSE 20 AMP
RESETTABLE
FUSE 20 AMP Input 2
Balanced Mic
Line
L
L R
R
Line
DIP Switches
1 2 3 4
DIP Switch Settings
SW Item On O
1
2
Input 1 Sensitivity 1V
3
VOX Enable
4
0.1V
Phantom Power Mic
Input 2 Sensitivity 1V 0.1V
On O
On O
Balanced
Mic Wiring
1 2 3 4
2 1
3
DIP Switch Settings
SW Item On O
1
2
Input 1 Sensitivity 1V
3
VOX Enable
4
0.1V
Phantom Power Mic
Input 2 Sensitivity 1V 0.1V
On O
On O

Redback® A 4395A 500W Mixer Amplier
www.redbackaudio.com.auRedback® Proudly Made In Australia
8
*Specications subject to change without notice
TROUBLE SHOOTING
If the REDBACK Phase 4 amplier fails to deliver the rated performance, check the following:
No Power, No Lights
Make sure amplier 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 will invalidate warranty.
Distorted Output
Check that the speaker type is correct for the output that you are using (ie. 4-16Ω, 70V or 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.
Amplier Keeps on Cutting In & Out
Make sure that there is adequate ventilation around the amplier. 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.
Backup Battery Not Charging
Make sure the link is tted to the charging link connector
No Output From 24V DC
Make sure the 24V DC Out connector is wired correctly.
SPECIFICATIONS
POWER OUTPUTS
A 4395A: ...................................................500 watts RMS
Distortion:................................................ < 0.5%, @ 1kHz
Output line: ......................................70V, 100V or 4 - 16Ω
FREQUENCY RESPONSE
Mic input:.............................................50Hz - 12kHz, -3dB
Line inputs: ..........................................50Hz - 15kHz, -3dB
SENSITIVITY
Mic inputs: ....................................................100mV or 1V
Line inputs:....................................................100mV or 1V
SIGNAL TO NOISE RATIO
Mic inputs: ..............................> 75dB below rated output
Line inputs:...............................> 81dB below rated output
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
CONTROLS
Mic inputs: .............................................................Volume
Line inputs:.............................................................Volume
Bass:..........................................................±10dB @ 100Hz
Treble:........................................................±10dB @ 10kHz
Power: ..........................................................On/off switch
Indicators:.....................Power, signal present, output peak
limiting, overtemp ,current limit, shutdown, VOX active,
24V DC, Mains
Power Supply: ....................................240V AC or 24V DC
FUSE PROTECTION
AC Fuse .................................................................10A AC
DC Fuse ................................................................ 20A DC
DIMENSIONS
.........................................................≈483W x 410D x 88H