Altronics redback A 4140 2 x 100W User manual

A 4140 2 x 100W
A 4150 2 x 200W
Phase 4 Stereo Amplifiers
®
www.altronics.com.au
Proudly Assembled in Australia
O
OPERA
PERATING TING
I
INSTRUCTIONS
NSTRUCTIONS
Distributed by Altronic Distributors Pty. Ltd. Perth. Western Australia.
Phone: [phone] Fax: [phone]
Internet: www.altronics.com.au

REDBACK Stereo Amplifiers
Page 2
Overview:
These compact, stylish, high performance, high fidelity
amplifiers can function as individual stand alone
amplifiers or a high performance stereo amplifier. Both
channels can be configured to operate in “bridge
mode”(mono) providing a massive 550W RMS power to
an 8 ohm load (model A 4150).
Incorporates a multi-staged thermally cued fan forced
cooling system. Output stages are continually thermally
monitored enabling automatic operation of a long life
computer style cooling fan to “off” , “low” or “high” air
flow through the custom designed tunnel heatsink. In
quiescent and low level operation the fans are inoperative.
Over temperature sensing is employed to shut down the
amplifiers in high temperature conditions, eg extreme
overload and/or overdrive mis-use. Re-start is automatic
once normal temperatures are attained.
The circuitry employed in the design protects the integrity
of the amplifiers under the following conditions: over
temperature, overload. The circuit even protects itself
under short circuit conditions. Each channel includes its
own front mounted volume control, recessed treble & bass
control and VU metering. On the rear, each channel
includes combination XLR / 6.35mm phono jacks for
inputs, heavy duty binding posts and Speakon®style
speaker connectors. In bridge mode operation, only one
volume control remains active.
Visual indication for each channel includes power on,
fault, clip, signal presence and output VU. The speaker
outputs are relay to prevent damage to the connected
speakers in case of a catastrophic failure. The relays
provide silent operation when amplifier is powered on or
off.
Features:
• Bridge mode capability
• Independent treble, bass and volume for each channel
• Silent de-thump start up and shut down
• Multi-Stage thermally cued cooling
• LED Bargraph VU meter
• Input signal presence indicator
• 2U 19" rack mount
• Thermal, overload and short circuit protection
• Australian designed and assembled
• 2 Year warranty
Operation:
Using RCA input: Plug the selected source (eg: DVD, CD,
Tuner) directly into the RCA sockets. Ensure the input
selection switch is set to RCA position.
Adjust front panel volume controls to desired level. Adjust
treble and bass for each channel as desired.
Using XLR/6.5mm input: Plug the selected source directly
into the XLR/6.5mm jack sockets. Ensure the input
selection switch is set to correct position.
Adjust front panel volume controls to desired level. Adjust
treble and bass for each channel as desired.
Once signal is applied the “signal present” LED will
illuminate on the front panel.
Speakers: Connect appropriately rated speakers to either
the binding post output or the speaker connector for each
channel. Speaker load should be between 4-8Ω. The output
will operate into 2 ohms but if the amplifier is driven hard,
the overload protection is likley to activate.
BCD I J KE F G H
LEGEND
1. IEC 240V Mains Connection ( with built in fuse)
2. Output channel 2 (speaker connector)
3. Output channel 2 (binding post)
4. Output channel 1 (binding post)
5. Output channel 1 (speaker connector)
6. Input selector (RCA or XLR)
7. Input channel 2 (XLR/6.5mm combination socket)
8. Bridged mode switch (on/off)
9. Input channel 1 (XLR/6.5mm combination socket)
10. RCA inputs (channel 1 & 2)
Channel 1 Channel 2
Channel 2 Channel 1

REDBACK Stereo Amplifiers
Page 3
Bridge mode: When operating in bridge mode connect the
speakers across the two positive terminals of the binding
post or between pins 1+ of the speaker connectors (See
wiring diagram). Ensure that the bridge mode switch on
the rear panel is set to ON position. In bridged mode only
the channel 1 volume control is active. The bridge mode
LED will illuminate on the front panel.
Protection: In the case of over temperature or severe
overload the amplifier unit will go into fault condition. In
this condition the speakers are disconnected to prevent
damage to the amplifier or speakers. Once the fault
condition is removed the amplifier will reset to normal
operation.
NOTE: Ensure that the amplifier is not continually
driven into clipping. Prolonged use in the clip mode
could cause permanent damage to connected speakers.
Volume controls should be adjusted so the “clip” LED’s
rarely illuminate.
TROUBLE SHOOTING
If the REDBACK amplifier fails to deliver the rated per-
formance, check the following:
NO POWER
(Power LED light does not illuminate)
Check mains fuse. Only replace with M205, 240V AC 5A
(A 4140) or 10A (A 4150) rated fuse.
DISTORTED OUTPUT
Check that the speaker type is correct for the output that
you are using. Measure speaker line impedance.
DO NOT CONNECT 100V LINE SPEAKERS
TO THESE AMPLIFIERS
VERY LOW OUTPUT
Make sure that the input is the correct level (check for
shorted connectors). Check for any short circuits on the
speaker line.
AMPLIFIER KEEPS ON CUTTING IN & OUT
Make sure that there is adequate ventilation around the
amplifier. Check the vent slots on the case are not covered
or blocked. Check also speaker types, ratings and for any
short circuits on the speaker line.
FAULT LED LIGHT ILLUMINATES
Make sure that there is adequate ventilation around the
amplifier. Check that the vent slots on the case are not
covered or blocked. Check also for any shorts on the
speaker line.
POWER OUTPUTS
A 4140:.............100 watts RMS into 8Ω, 150 watts RMS into 4Ω
Bridge mode 250 watts RMS into 8Ω
A 4150:.............200 watts RMS into 8Ω, 300 watts RMS into 4Ω
Bridge mode 550 watts RMS into 8Ω
Distortion:........................................................< 0.01%, @ 1kHz
Frequency response:..................................20Hz - 20kHz, -3dB
Speaker outputs:...............................................................4 - 8Ω
Sensitivity: .......................................................................500mV
Signal to noise ratio:....................................................> 100 dB
OUTPUT CONNECTORS
Speakers:..........Binding posts, 4 pin Speakon®style connectors
INPUT CONNECTORS
Inputs: ..............................Combination 3 pin XLR /6.35mm jack
240V AC power:.......................................IEC power connectors
CONTROLS
Master:.............................................................................Volume
Power:.....................................................................On/off switch
Treble & bass:.................................± 10 dB @ 100 Hz & 10kHz
Indicators: .........................................................................Power
Fault
VU meter
Clip
Signal present
Bridged mode
Power supply:...............................................................240V AC
FUSE PROTECTION
A 4140:.............................................5A AC, Internal 3A DC(4 of)
A 4150:..........................................10A AC, Internal 5A DC (4 of)
WEIGHT / DIMENSIONS
A 4140: ...........................................................................≈12.5kg
A 4150: ..............................................................................≈15kg
Dimensions:.............................................≈483W x 330D x 88H
Colour: ................................................................................Black
*Specifications subject to change without notice
SPECIFICATIONS

Page 4
++
+
8ΩMin
Bridged
(Binding Post)
++
+
8ΩMin
Pin 1+ Pin 1+
Bridged
(Speaker Connector)
Bridged mode wiring: Connect to binding post or speaker connectors as
desired. Bridge mode wiring must be to the positive terminals.
Load must be 8Ω.
++
+
4ΩMin
Stereo
(Binding Post)
+
4ΩMin
Channel 1 Channel 2
++
+
4ΩMin
Pin 1+
Stereo
(Speaker Connector)
Pin 1-
+
Pin 1+
Pin 1-
4ΩMin
Channel 1 Channel 2
Stereo mode wiring: Connect to binding post or speaker connectors as
desired. Ensure load is correct. 4Ωminimum.
3 pin XLR input connector
1
2
3
Front view
Audio
“Cold”
Audio
“Hot” Audio
Shield
INPUT AND OUTPUT CONNECTION WIRING DETAILS
HOT COLD EARTH
6.35mm Input Connector
RCA Input Connector
EARTH
SIGNAL