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REDBACK A 4020A 30 Watt Amplifier
Power output:
...................................... 30 watts RMS
Distortion:
.......................................... < 0.5% @ 1kHz
Output line: .......................................................... 100V
Signal
All volume controls min, typically 72dB below rated out-
put. All inputs display same S/N ratio.
Frequency Response
Mic:
.............................................. 52Hz - 10kHz, -3dB
Line:
............................................ 40Hz - 10kHz, -3dB
Input Sensitivity
Mic input:
.......................................... 2.6mV balanced
Line inputs:
...................................................... 150mV
Controls
Volume 1:
................................ Controls mic 1 / line 1
Volume 2:
............................................ Controls line 2
Bass:
.................................................. ±10dB @ 100Hz
Treble:
.............................................. ±13dB @ 10kHz
Power:
.................................................... On/off switch
Output Connectors
Speakers:
.......................................... Screw terminals
MUTING
VOX only (-79dB)
Input Connectors
Mic input:
...................................... 3 pin XLR balanced
Line inputs:
.............. RCA stereo socket, bridged mono
240V AC power:
........................ IEC power connector
Power supply:
................................................ 240V AC
Indicators:
........................................................ Power
Fuse protection:
........................................ 500mA AC
3A x 2 DC internal
Size:
.................................... 300W x 220D x 74H mm
Weight:
............................................................
≈
4.8kg
Colour:
.............................................................. Black
Specifications
Trouble Shooting
No Power
(Power LED light does not illuminate)
Check mains fuse. Only replace with M205, 240V AC
0.5A rated fuse.
Distorted Output
Check that the speaker type is correct for the output
that you are using. Check for any short circuits on the
speaker line.
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.
Continually Blows fuses
Make sure that the speaker line is not shorted. Check
also speaker types, ratings and if on correct output.
Amplifier Keeps Cutting In and Out
Make sure that there is adequate ventilation around the
amplifier. Check the vent slots on the case are not cov-
ered or blocked. Check also speaker types, ratings
and for any short circuits on the speaker line.
From Microphone
Input
Unbalanced
1
2
3
Signal
Shield
XLR Mic
Input
From Microphone
Input
Balanced
Shield
XLR Mic
Input
Signal
1
2
3
Microphone Connections
Connector Type:
..................XLR 3Pin Female
Pin 1:
.....................................................Earth
Pin 2:
...............................Signal Inphase (hot)
Pin 3:
......................Signal Out of Phase (cold)
Figure 1.
