background image

4

INTRODUCTION

Thank you for purchasing a MARTIN AUDIO power amplifier. This manual
contains important information on operating your amplifier correctly and
safely. Please take some time to read this manual and familiarize yourself
with the advanced features of this amplifier.

4.1

The front panel 

Figure 1. Front panel

1. Carry/protection handle
Both handles can be used to carry the amplifier; they also act as protection
for the front panel and controls. In fixed installations or where rack front
covers are too shallow, they may be removed by unscrewing the retaining
bolts behind the front panel. 

2. Input level attenuators
These controls are used to set the signal level entering the amplifier. They
are calibrated in dB to assist the set up of active loudspeaker systems.  
(See page 16).

3. Protect indicator LED
This indicator illuminates if the amplifier attempts to function above its
maximum operating temperature (90ºC). The indicator first comes on as a
warning to either turn down the input level or check the cooling
arrangements, after which point the amplifier will mute the input signal.
When the cooling fans have returned the output heat sinks to the normal
operating temperature, the input signal is un-muted.

The Protect LED also illuminates when constant signals above 12kHz at full
power are detected at the output terminals. When this occurs the input
signal is muted until the VHF signal is no longer present. (See page 17).

4.  Clip/limit indicator LED
This indicator signals when the amplifier output is clipping or limiting. It has
two different indication states:
•  When the clip limiter is engaged, it has a short time constant and 

illuminates briefly. (See pages 16-17).

•  When the clip limiter is not engaged, it has an increased time constant 

and illuminates for a longer period. 

Martin Audio – MA2.8 Power Amplifier

E

NGLISH

4

➂➃

<

>

PRINT

GUIDES

CONTENTS

APPLICATIONS GUIDE

Содержание MA2.8

Страница 1: ...ections 8 5 7 Connecting speakers 11 5 8 Impedance matching MLS switch 13 6 OPERATION MODES 13 6 1 Stereo operation 13 6 2 Tandem mono 13 6 3 Bridged mono 14 6 4 Stereo reverse 14 7 OPERATION 15 7 1 O...

Страница 2: ...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 Do not blo...

Страница 3: ...es 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 automaticall...

Страница 4: ...es 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 arrangements af...

Страница 5: ...drive see page 12 3 Clip limiter switch Turns the clip limiter on and off See page 17 4 Input jack Alternative to using input XLR or for linking inputs with other amplifiers See page 9 5 Input signal...

Страница 6: ...ront 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 of the rac...

Страница 7: ...ference 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 consumption...

Страница 8: ...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 ampli...

Страница 9: ...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 connecto...

Страница 10: ...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 Balanced lin...

Страница 11: ...rs connected 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...

Страница 12: ...positions you are allocating a portion of power from 3000 watts Martin Audio MA2 8 Power Amplifier ENGLISH 12 MA2 8 MLS Switch Position LOAD CONFIGURATION 5dB 4dB 2dB 0dB 16 ohms Stereo 2 channel 160...

Страница 13: ...s 2 ohms per channel 6 2 Tandem mono For tandem dual channel single input operation depress the Link switch Both channels can now be driven by a signal at either input connector The output connection...

Страница 14: ...is can cause serious damage The recommended minimum nominal impedance for bridged mono is 4 ohms equivalent to driving both channels at 2 ohms Driving bridged loads of less than 4 ohms may cause a the...

Страница 15: ...about operating voltage and power consumption Make sure that the switches on the rear panel for operation modes clip limiters and the MLS switches are in the correct position See pages 13 and 14 about...

Страница 16: ...setting which has a sensitivity of 0dBu 0 775Vrms for full power in 4 ohms 7 5 Indicators Figure 13 Front panel indicators The two bottom green ON LED s indicate when the power supply and output stag...

Страница 17: ...the relevant clip limit switch 2 Some manufacturers of loudspeaker processors do not recommend the use of clip limiters in amplifiers as they tend to upset the tracking of the processor s limiters Ap...

Страница 18: ...e short circuit is removed AC mains voltage protection If the AC mains voltage is outside the operational window over or under voltage the power supply will automatically shut down When the mains volt...

Страница 19: ...ot only by the design of the power supply and heatsink but also by the use of an alloy chassis making rear rack supports unnecessary in most applications Switch mode power supply SMPS Switch mode powe...

Страница 20: ...ess of speaker demands and AC line conditions Minimum Load Switch MLS Thanks to the regulated SMPS the maximum power available for the output stages can be adjusted without increased heat dissipation...

Страница 21: ...sts 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 two cases...

Страница 22: ...ation 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 Please contac...

Страница 23: ...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 circuit in...

Страница 24: ...ts 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 tear Units...

Страница 25: ...4 ohms 0 08 POWER MATRIX MLS SWITCH SETTING LOAD CONFIGURATION 5dB 4dB 2dB 0dB 16 ohms Stereo 2 channel 160W 180W 340W 520W 8 ohms Stereo 2 channel 300W 350W 650W 1100W 4 ohms Stereo 2 channel 570W 68...

Страница 26: ...ire 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 here to ret...

Страница 27: ...MARTIN AUDIO L O N D O N The Martin Experience ENGLISH MA2 8 Power Amplifier User s Guide PRINT GUIDES CONTENTS APPLICATIONS GUIDE...

Отзывы: