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Martin Audio – MA1.3 Power Amplifier

E

NGLISH

8

MAX OUTPUT POWER

MAINS INPUT POWER

Power

Full Power

1/3 Power

1/8 Power

Idle

sine wave

note 1

note 2

MA1.3

8 ohms

2X

350

1300

700

400

140

4 ohms

2X

650

2300

1300

800

140

2 ohms

2X

900

3600

1900

1100

140

note 1 Average power with music as program  

note 2 Normal music power with 9dB headroom,

source. The amplifier driven to clip level.

IEC standard power rating.

Table 1.

The current draw can be calculated by dividing the mains input power by
the mains voltage.  We recommend that you design the power distribution
for at least the current at 1/8 power or 1/3 power for heavy duty demand
like discos etc.

The heat power can be calculated as the following example:
If we consider a headroom of at least 9dB and a 4 ohm load on an amplifier
producing 650 watts per channel. The 1/8 power per channel is then; 
650 ÷ 8 = 81 watts, total output; 2 x 81 = 162 watts.
The power consumption according to the chart above is then 800 watts.

The heat power produced is the difference between the power
consumption and power output; 800 - 162 = 638 watts per amplifier.

5.6

Input connections

Both inputs are balanced on 3 pin XLR type connectors and wired pin 2
hot, pin 3 cold, pin 1 ground/shield:

PIN 1

-

SIG. GROUND/SHIELD

PIN 2

-

HOT (+) 

PIN 3

-

COLD (-)

Figure 3. XLR input connector pin-out

1

2

3

SIG. GND.

+

CONTENTS

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GUIDES

Summary of Contents for MA1.3

Page 1: ...consumption 7 5 6 Input connections 8 5 7 Connecting speakers 11 6 OPERATION MODES 11 6 1 Stereo operation 11 6 2 Tandem mono 12 6 3 Bridged mono 12 6 4 Stereo reverse 13 7 OPERATION 13 7 1 Operation...

Page 2: ...any other voltage source such as battery mains source or power supply regardless of whether the amplifier is turned on or off Do not run the output of any amplifier back into another channel s input...

Page 3: ...roduct uses radio frequency energy and if not used or installed in accordance with these operating instructions may cause interference to other equipment Compliance with the EMC directive does not aut...

Page 4: ...illuminates if the amplifier attempts to function above its maximum operating temperature 90 C The indicator first comes on as a warning to either turn down the input level or check the cooling arran...

Page 5: ...n and off See page 15 3 Input jack Alternative to using input XLR or for linking inputs with other amplifiers See page 9 4 Input signal XLR See page 8 5 Polarity reverse switch for channel B For rever...

Page 6: ...upply in front of the amplifier and that the rear of the amplifier has sufficient space to allow the exhaust to escape If the amplifier is rack mounted do not use covers or doors on the front or rear...

Page 7: ...nd for reference otherwise a current loop is formed via the signal ground Use the balanced input to avoid hum and interference 5 5 Power consumption There are three ways to define the power current co...

Page 8: ...least the current at 1 8 power or 1 3 power for heavy duty demand like discos etc The heat power can be calculated as the following example If we consider a headroom of at least 9dB and a 4 ohm load o...

Page 9: ...isy chain use the TRS jacks provided on each channel The input circuits also have high enough headroom to accept the maximum output level from virtually any low level signal source Figure 5 Rear panel...

Page 10: ...onnected to the shield at the source The hum and noise rejection for the cable is equivalent to that for a balanced line To minimize hum in the audio use balanced inputs whenever possible Figure 8 Bal...

Page 11: ...nected out of polarity can degrade sound quality Keep the speaker cables as short as possible and use a good quality stranded speaker cable Do not use shielded wire such as microphone or guitar cable...

Page 12: ...s for linking etc Do not use the remaining XLR and TRS as input jacks simultaneously for mixing or other purposes To obtain an output connect the speaker leads to pin 1 on channel A Speakon to speaker...

Page 13: ...nt for signals below 100Hz sub bass etc 7 OPERATION 7 1 Operation precautions Make sure that the power switch is off before making any input or output connections or operating the switches on rear pan...

Page 14: ...on depressed switch to give you plenty of fader movement On the other hand for a disco mixer that operates at a nominal level of 0dBu use the upper position setting which has a sensitivity of 0dBu 0 7...

Page 15: ...limiters in amplifiers as they tend to upset the tracking of the processor s limiters Apart from this one exception MARTIN AUDIO recommend leaving the clip limiters switched on button depressed As a b...

Page 16: ...D s then indicate that the power supply and output stage is operating correctly D C protection There are two types of DC protection Fuses on the supply branches of each channel A DC crowbar protection...

Page 17: ...f the AC line voltage falls by more than 20 Figure 13 Current voltage characteristic of different power supply topologies 1 Conventional power supply shows voltage drop due to internal resistance 2 Re...

Page 18: ...ts and bursts up to 1kV conducted through the cables to the unit Electromagnetic fields up to 3V m radiated on the unit and the cables in the frequency range of 27 500MHz We have extended the tests in...

Page 19: ...t AC operation only For use on 115 Volts AC internal modifications to the power supply board must be made Warning This modification should only be carried out by an experienced service technician Plea...

Page 20: ...If it is remove possible high frequency oscillations from the relevant input Fault The amplifier goes into thermal protection when driven at low level Check that your loudspeaker has not got a short c...

Page 21: ...ng accidents act of God war civil insurrection misuse abuse operation with incorrect AC voltage operation with faulty associated equipment exposure to inclement weather conditions and normal wear and...

Page 22: ...1W 600W 4 ohms 0 08 THD at 1kHz and 600W 4 ohms 0 03 DIM 30 at 300W 4 ohms 0 02 CCIF 13 and 14kHz at 200W 4 ohms 0 02 SMPTE 60Hz and 7kHz at 300W 4 ohms 0 05 POWER MATRIX LOAD CONFIGURATION POWER OUTP...

Page 23: ...kinghamshire HP12 3SL England Telephone 44 0 1494 535312 Facsimile 44 0 1494 438669 Web www martin audio com E mail info martin audio com The Martin Experience MARTIN AUDIO L O N D O N Please Click he...

Page 24: ...MARTIN AUDIO L O N D O N The Martin Experience ENGLISH MA1 3 Power Amplifier User s Guide CONTENTS PRINT GUIDES...

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