User manual MARTIN AUDIO MA2.8

[. . . ] CONTENTS < 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. 5 8 9 10 11 12 13 14 > PRINT APPLICATIONS GUIDE GUIDES CONTENTS (ENGLISH) UNPACKING WARNINGS USER RESPONSIBILITY Speaker damage Shock hazard Radio interference INTRODUCTION Front panel Rear panel INSTALLATION Mounting Cooling Operating voltage Grounding Power consumption Input connections Connecting speakers Impedance matching (MLS switch) OPERATION MODES Stereo operation Tandem mono Bridged mono Stereo reverse OPERATION Operation precautions Powering up - Soft start Input attenuators Gain switch Indicators PROTECTION FEATURES DESIGN FEATURES SPECIFICATIONS APPENDIX A MAINTENANCE WARRANTY TECHNICAL SPECIFICATIONS Page No 2 2 3 3 3 3 4 4 5 6 6 6 6 7 7 8 11 13 13 13 13 14 14 15 15 15 16 16 16 17 19 21 22 23 24 25 MARTIN AUDIO LONDON The Martin Experience Martin Audio ­ MA2. 8 Power Amplifier CONTENTS < > ENGLISH PRINT APPLICATIONS GUIDE 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 EN55103-1:1996 EN55103-2:1996 EN60065:1993 Electrical Safety 1 UNPACKING Each Martin Audio MA Series amplifier is built to the highest standard and thoroughly inspected before it leaves the factory. After unpacking the unit, examine it carefully for any signs of transit damage and inform your dealer if such damage is found. It is suggested that you retain the original packaging so that the unit can be repackaged at a future date if necessary. Please note that Martin Audio and its distributors cannot accept responsibility for damage to any returned product through the use of non-approved packaging. 2 · · · WARNINGS Do not use this amplifier if the mains cable is damaged. [. . . ] Both channels can now be driven by a signal at either input connector. Do not use the remaining XLR and TRS connectors for mixing or other purposes. Both level attenuators are active, allowing you to set different levels for each channel. Never connect either output terminal to ground or in parallel. dB 0 13 Martin Audio ­ MA2. 8 Power Amplifier CONTENTS < > ENGLISH PRINT APPLICATIONS GUIDE GUIDES 6. 3 Bridged mono To bridge the amplifier, depress the Link switch (7) and Phase reverse switch (6). 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 positive terminal and pin +1 on channel B Speakon to speaker negative terminal. Do not connect speakers to channel A or B in the normal manner in bridge mode, as this 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 thermal overload. 2 3 1 + ­ + CH A + ­ ­ + I/P LINK ­ 2 3 1 PHASE INVERT + ­ + CH B + ­ ­ Figure 11. Bridge mono connection Both level attenuators must be at the same position. Apart from depressing the Link switch, you also depress the Phase reverse switch, as in the Bridge mono. To compensate for that, connect pin +1 on channel B Speakon to speaker negative terminal and pin -1 on channel B to speaker positive terminal. 14 Martin Audio ­ MA2. 8 Power Amplifier CONTENTS < > ENGLISH PRINT APPLICATIONS GUIDE GUIDES 2 3 1 + ­ + CH A + ­ + ­ I/P LINK 2 3 1 PHASE INVERT + ­ + 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. 1 Operation precautions · Make sure that the power switch is off before making any input or output connections or operating the switches on rear panel. · Make sure that the AC mains is correct and the same as that printed on the rear panel of the amplifier. · Make sure that the switches on the rear panel for operation modes, clip limiters and the MLSTM switches are in the correct position. See pages 13 and 14 about operation modes, page 16, about clip limiters and page 12 for the MLS switches. · It is always a good idea to turn down the gain controls during power up as this prevents speaker damage, especially if there is a high level signal at the input. 7. 2 Powering up - Soft start 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. [. . . ] concert touring or industrial music, it is recommended that you have your amplifier serviced every 3 years, purely as a preventative measure. Troubleshooting These are typical things to check if you think your amplifier is faulty: Fault: No output. If the -40dB LED is functioning there is nothing wrong with the amplifier and the likely cause is an unsecured Speakon. If it is, remove possible high frequency oscillations from the relevant input. [. . . ]