User manual MARTIN AUDIO MA4.2S SCHEMATICS

[. . . ] Do not operate this amplifier if liquid ingress is suspected. Do not stand water or any other liquid on, or near the amplifier. Do not operate the amplifier if wet or standing in liquid. Do not block the air intake or exhaust ports. [. . . ] This results in twice the voltage swing, four times the peak power and just less than three times the full power of a single channel. This is because the coil is driven with positive voltage at one pole and an equivalent negative voltage at the other pole. So, if an 8 ohms load is connected in bridged mode, one channel shares one 4 ohms part of the load, and the other channel shares the other 4 ohms part. The power into 4 ohms from an MA4. 2S is 200W. So, the total bridged power into the 8 ohms load will be 2 x 200 = 400W. 6 6. 1 INSTALLATION Mounting The amplifier is two rack unit's high (2U) and weighs 13. 2Kg (29lbs) 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. It is also recommended that rear supports are used for amplifiers mounted in the middle of the rack, especially if used as part of a portable system. 6. 2 Cooling Your amplifier uses a forced air cooling system to maintain a low and even operating temperature. All fan cooled MARTIN AUDIO MA Series amplifiers have front to rear cooling. Never try to reverse the airflow, as the amplifier needs a pressure chamber between the fans and heat sink, and this only operates in one direction of the airflow. No music program material requires the full steady state continuous power of an amplifier, this operating condition is only valid during amplifier bench testing. Second, the maximum expected average current under worst case program material, which is 1/3 of full power according to the FTC-standard. At this level normal program music will be in a state of constant clip and is therefore the highest power level that can be achieved without completely obliterating the program material. Lastly, the "normal operating power", as defined by EN 60065 as a measurement level for approval and testing to this standard. The normal operating power is measured using pink noise, with an average output power equal to 1/8 of full power. The one-eighth power is the maximum level program music can be re-played without continuous amplifier clipping, this corresponds to a headroom of only 9dB's, which is very low for normal program material. MAX OUTPUT POWER MA4. 2S 8 ohms 4 ohms 2 ohms 4x 4x 4x Power [W] 130 200 270 MAINS INPUT POWER 1/3 Power note 1 480 720 1065 1/8 Power note 2 300 470 740 Idle 85 85 85 note 1 note 2 Average power with music as program source. i Normal music power with 9dB headroom, IEC standard power rating. 10 Martin Audio ­ MA4. 2S Amplifier CONTENTS < > PRINT ENGLISH 6. 5. 1 Calculation 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 required current at 1/8 power, or 1/3 power for heavy-duty demands such as concert touring and Industrial music etc. The heat power can be calculated as following: If a headroom figure of at least 5dB (1/3 full power) is used with a 4 ohms load on all four channels of the amplifier. The 1/3 power per channel is then; 200 / 3 = 67 watts, and total output power is; 4 x 67 = 267 watts. The mains power consumption from the chart above is 720 watts. The heat power produced is the difference between the power consumption and output power; 720 - 267 = 453 watts total for the amplifier. MA4. 2S HEAT POWER 1/3 POWER 1/8 POWER 1/3 POWER 1/8 POWER 1/3 POWER 1/8 POWER WATTS Kcal/hour BTU/hour 8 Ohm 307 235 260 200 1050 800 4 Ohm 453 370 390 320 1550 1260 2 Ohm 705 605 610 520 2410 2060 1/3 Power level = Average power with music as programme material (continuous clipping) 1/8 Power level = Normal operating power with music as programme material (occasional clipping) 7 7. 1 CONNECTIONS Input connections 7. 1. 1 Balanced inputs The Input connectors are Neutrik combo jacks and incorporate an XLR and _" (6. 3mm) jack. They are active balanced and wired as below: PIN 1 PIN 2 PIN 3 GROUND/SHIELD HOT (+) COLD (-) 11 Martin Audio ­ MA4. 2S Amplifier CONTENTS < > PRINT ENGLISH The Neutrik Combo jack is wired in parallel with the XLR. TIP RING SLEEVE CH. D HOT COLD SHIELD/GROUND CH. C iL /k Bid ge C+ D nr INPUTS CH. B iL /k B dge A + B n ri CH. A Fixed gain 32 dB XLR Pin 1 2 3 Scrn Pos Neg 1/ 4 " Sleeve Tip Ring Must be grounded 2 30-240V 5 0 -60Hz The input impedance is high enough (20K ohms balanced) to allow "daisy-chaining", or multiple parallel input connections. [. . . ] These conditions usually occur after prolonged use, e. g. in environments using "cracked- oil" smoke machines. If you are using your amplifier for heavy-duty use i. e. concert touring or industrial music it is recommended that you have your amplifier serviced every 3 years, purely as a preventative measure. 10. 1 Troubleshooting These are typical things to check if you think your amplifier is faulty Fault: No output. [. . . ]