< CONTENTS > APPLICATIONS GUIDE PRINT CONTENTS (ENGLISH) 1 2 3 3.1 3.2 3.3 4 4.1 4.2 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 6 6.1 6.2 6.3 6.4 7 7.1 7.2 7.3 7.4 7.
> APPLICATIONS GUIDE PRINT GUIDES This equipment conforms to the requirements of the EMC Directive 89/336/EEC, amended by 92/31/EEC and 93/68/EEC and the requirements of the Low Voltage Directive 73/23/EEC, amended by 93/68/EEC. Standards Applied EMC Emission Immunity Electrical Safety 1 EN55103-1:1996 EN55103-2:1996 EN60065:1993 UNPACKING Each Martin Audio MA Series amplifier is built to the highest standard and thoroughly inspected before it leaves the factory.
> APPLICATIONS GUIDE PRINT GUIDES USER RESPONSIBILITY 3.1 Speaker damage Many loudspeakers can be easily damaged or destroyed by overpowering, especially with the high power available from a bridged amplifier. Always check the speakers continuous and peak power capabilities. Even if the gain is reduced by using the amplifier's front panel attenuator, it is still possible to reach full output power, if the input signal level is high enough. 3.
> APPLICATIONS GUIDE PRINT GUIDES 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 ➄ ➀ ➂➃ ➁ ➁ Figure 1. Front panel ➄ ➅ 1.
< > APPLICATIONS GUIDE PRINT ENGLISH CONTENTS GUIDES 5. Fan grille filter A foam filter is located behind the front panel grille to prevent dust entering the amplifier. 6. Power switch This is used to power up the amplifier. (See page 7 and 15) 4.2 The rear panel ➃ ➃ ➁ ➀ ➀ ➁ Figure 2. Rear panel ➂ ➄ ➈ ➂ ➅ ➆ 1. Speakon connector This type of speaker connector may be unfamiliar to some users. A full description is found in the operation section. (See page 11). 2.
5 > APPLICATIONS GUIDE PRINT GUIDES INSTALLATION 5.1 Mounting The amplifier is two rack units high (2U) and will mount in a standard EIA 19'' rack. Amplifiers may be stacked directly on top of each other. There is no need for spacing between units. If it is the intention to fill a rack with amplifiers, we recommend racking is started from the bottom of the rack.
< > APPLICATIONS GUIDE PRINT BROWN BLUE GREEN/YELLOW - GUIDES LIVE NEUTRAL EARTH Once connected to a suitable AC supply, the amplifier can be started with the power switch. When you power up the amplifier it takes a couple of seconds to self check (this is known as the "soft start" or "slow start" sequence). The fans then blow at high speed before going into "idle". The 2 bottom green LED's then illuminate to show the amplifier is operational. 5.
< > APPLICATIONS GUIDE PRINT MAX OUTPUT POWER MAINS INPUT POWER Power MA2.8 GUIDES Full Power 1/3 Power 1/8 Power sine wave note 1 note 2 Idle 8 ohms 2X 1100 3100 1300 700 130 4 ohms 2X 1400 4300 1700 900 130 2 ohms 2X 1400 4700 1700 900 130 note 1 Average power with music as program note 2 source. The amplifier driven to clip level. Normal music power with 9dB headroom, IEC standard power rating. Table 1.
< > APPLICATIONS GUIDE PRINT GUIDES There are also TRS jacks for linking etc. They are wired as follows: TIP RING SLEEVE - HOT (+) COLD (-) SHIELD/SIG. GROUND SIG.GND – + Figure 4. TRS phone plug The input impedance is sufficiently high (20kohms balanced) to allow "daisy-chaining", or multiple parallel input connections. To daisy-chain, use the TRS jacks provided on each channel.
< > APPLICATIONS GUIDE PRINT GUIDES Do not use XLR and TRS jacks on the same channel simultaneously for mixing or other purposes. Balanced Output Signal Grounded Shield 1 Amplifier Input 2 2 3 Amplifier Input Balanced Output Chassis Grounded Shield 1 1 3 2 2 3 1 3 Figure 6. Balanced line To use an unbalanced source, connect pin 3 (ring on TRS jack) to the shield of the connector. If you leave one pin disconnected, you will lose 6dB in gain.
< > APPLICATIONS GUIDE PRINT GUIDES 5.7 Connecting speakers Speaker connections are made via the two Neutrik NL4FC Speakon connectors (1). These connectors meet the EC safety requirements. They are wired as follows: Pin Pin Pin Pin -1 +1 -2 +2 Speaker ground. Speaker positive. No connection. No connection. 21+ 2+ 1- Figure 9. Speakon connector Please note that this is the standard wiring convention for Speakon connectors adopted worldwide.
< > APPLICATIONS GUIDE PRINT MA2.8 GUIDES MLS Switch Position LOAD CONFIGURATION -5dB 16 ohms Stereo (2 channel) 160W 8 ohms 4 ohms Stereo (2 channel) Stereo (2 channel) 300W 570W -4dB -2dB 0dB 180W 340W 520W 650W 1100W 1100W 1400W 350W 680W 1900W[2] 2 ohms Stereo (2 channel) 1040W 1200W 1200W 1400W[1] 1400W[2] 2900W[2] 16 ohms Bridged mono 600W 700W 1300W 2000W 8 ohms Bridged mono 1200W 1400W 2200W 2800W 4 ohms Bridged mono 2100W 2400W 2400W 2800W Table 2.
> APPLICATIONS GUIDE PRINT GUIDES dB MLS Switch OUTPUT CH.B 0 1+ CH.B+ 1– CH.B– -2 -4 -5 Figure 10. MLS switches on rear panel 6 OPERATION MODES 6.1 Stereo operation For stereo (dual channel) operation, leave the Link and Phase reverse switches in the un-depressed position. In this mode, both channels operate independently of each other, with their level attenuators controlling their respective levels. Never connect either output terminal to ground or in parallel.
< > APPLICATIONS GUIDE PRINT GUIDES 6.3 Bridged mono To bridge the amplifier, depress the Link switch (7) and Phase reverse switch (6). Both channels are then driven by a single signal at either input. You can use any remaining input connectors for linking etc. Do not use the remaining XLR and TRS as input jacks simultaneously for mixing or other purposes.
> 2 APPLICATIONS GUIDE PRINT + 1 3 + – CH A + – 1 PHASE INVERT 3 + – I/P LINK 2 GUIDES + + – CH B + – – + Figure 12. Stereo reverse mode Channel A output is connected as in the normal stereo mode. By having channel A and B operating in opposite polarity, the energy storage in the power supply is more efficient. This means that the amplifier can deliver up to 10% more power than in tandem mono mode. This is significant for signals below 100Hz (sub bass etc.). 7 OPERATION 7.
< > APPLICATIONS GUIDE PRINT GUIDES 7.3 Input attenuators The two input level attenuators on the front panel adjust the signal level for their respective amplifier channel in all modes. They are calibrated in dB to assist setting up active loudspeaker systems. In bridged mode, both controls must be in the same position, so that the speaker load will be shared equally between the channels. 7.4 Gain switch The gain switch located on the rear panel is for changing the input sensitivity of the amplifier.
8 > APPLICATIONS GUIDE PRINT GUIDES PROTECTION FEATURES Each MARTIN AUDIO MA Series amplifier has many advanced protection features that will protect both the amplifier and the speakers connected to it, should a fault condition arise. Under normal use these features are inaudible. All protection circuits are independent. Output limiter An output limiter is included to avoid amplifier clipping.
< > APPLICATIONS GUIDE PRINT GUIDES input signal. (This is indicated on the front panel (3) labelled “Protect”). After five seconds the outputs will un-mute and return to normal operation, unless the output signal has remained unchanged in which case the VHF protection will re-initiate. This circuit is inaudible in normal use, however it can be turned off. If the VHF protection is required to be turned off i.e. for studio monitors, please consult your supplier, as this is a non-user adjustment.
9 > APPLICATIONS GUIDE PRINT GUIDES DESIGN FEATURES Cooling MARTIN AUDIO MA Series amplifiers run very cool due to a patented heat exchanger. The bi-polar output devices are mounted directly onto a copper heat sink thereby avoiding thermal losses normally found when using mica washers. The heat sink is mounted horizontally in front of a pressure chamber and the air flow is constant along the whole heat sink.
< > APPLICATIONS GUIDE PRINT GUIDES 90 80 70 Voltage [V] 60 50 2 40 30 20 1 10 3 0 0 5 10 15 20 25 30 35 40 45 50 Current [A] Figure 14. Current-voltage characteristic of different power supply topologies. 1) Conventional power supply shows voltage drop due to internal resistance. 2) Regulated power supply used by MARTIN AUDIO. 3) Unregulated switch mode power supply with current limiting.
< 10 > APPLICATIONS GUIDE PRINT GUIDES SPECIFICATIONS Safety approvals MARTIN AUDIO MA Series amplifiers are designed to meet EN60065 electrical safety standards. EMC approvals EMC stands for Electro Magnetic Compatibility. This implies that the equipment should have low emission of radio frequencies, directly as electromagnetic fields in the air and as conducted from the cables from and to the unit.
< 11 > APPLICATIONS GUIDE PRINT GUIDES APPENDIX A Mains voltage selection All Martin Audio MA Series amplifiers are normally shipped for 230 Volt 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. Please contact MARTIN AUDIO for information. 22 Martin Audio – MA2.
< 12 > APPLICATIONS GUIDE PRINT GUIDES MAINTENANCE Under normal use the amplifier should give years of trouble free service. The only user maintenance required from the user is to vacuum the front grille periodically. In some extreme cases it may be necessary for your supplier to clean the inside of the amplifier. These conditions usually occur after prolonged use in environments using "cracked-oil" smoke machines. If you are using your amplifier for heavy-duty use i.e.
< 13 > APPLICATIONS GUIDE PRINT GUIDES WARRANTY General The MA2.8 Powered Amplifier is warranted to be free from defects in components and factory workmanship under normal use and service, for a period of one year from the date of original purchase.
< 14 > APPLICATIONS GUIDE PRINT GUIDES TECHNICAL SPECIFICATIONS MA2.8 INPUT IMPEDANCE GAIN SELECT SWITCH CMRR@1kHz OUTPUT IMPEDANCE@1kHz POWER BANDWIDTH SLEW RATE HUM/NOISE CHANNEL SEPARATION MAINS OPERATING VOLTAGE PROTECTION 20kohms (balanced) 10kohms single ended 38dB (I/P sens 0.775V), 32dB (I/P sens 1.55V) >50dB 0.06 ohms 10Hz - 20kHz 20V/us <-105dB 1kHz - 90dB 10kHz - 80dB 120 - 270 (minimum start voltage 190) full output power maintained 180 - 280V. Optional (65 - 135V) operation.
CONTENTS < > APPLICATIONS GUIDE PRINT MA2.8 GUIDES Power Amplifier Please Click here to return to main menu Please Click here to visit our website MARTIN AUDIO L O N D O N The Martin Experience Century Point, Halifax Road, Cressex Business Park, High Wycombe, Buckinghamshire HP12 3SL, England. Telephone: +44 (0)1494 535312 Facsimile: +44 (0)1494 438669 Web: www.martin-audio.com E-mail: info@martin-audio.
CONTENTS < > APPLICATIONS GUIDE PRINT MA2.
