User manual MACKIE M1200

[. . . ] TM FULL SYMMETRY DUAL DIFFERENTIAL HIGH CURRENT DESIGN PROFESSIONAL POWER AMPLIFIER CH OL 3v 18 2v ­6 PROTECT SHORT TEMP STATUS ­9 26 8 28 ­20 ­20 ­9 14 ­6 16 24 20 22 INTERNAL STATUS ­3 ­3 OL GAIN/dB GAIN/dB CH CH CH 3v 1 2 ON 1 2 18 20 22 2v 16 24 14 26 8 28 OFF 0 0 0 0 30 1v 30 1v SIG SIG SENSITIVITY CH 1& 2 COLD HOT SENSITIVITY 1. 23v (+4dBu) 1. 23v (+4dBu) POWER TM CAUTION TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. REFER SERVICING TO QUALIFIED PERSONNEL. WARNING: SERIAL NUMBER MANUFACTURING DATE 1 CHANNEL / BRIDGE / MONO LOW CUT FILTER BALANCED OR UNBALANCED STAGE MONITOR AMP MODE CHANNEL STEREO TYPICAL RISK OF ELECTRIC SHOCK DO NOT OPEN AVIS: RISCQUE DE CHOC ÉLECTRIQUE -- NE PAS OUVRIR UTILISE UN FUSIBLE DE RECHANGE DE MÊME TYPE. DEBRANCHER AVANT DE REMPLACER LE FUSIBLE TYPICAL 35 Hz INPUT MONO BRIDGE INPUT BALANCED OR UNBALANCED LOW CUT FILTER TYPICAL 35 Hz 2 STAGE MONITOR REPLACE WITH THE SAME TYPE FUSE AND RATING. DISCONNECT SUPPLY CORD BEFORE CHANGING FUSE (MONO BRIDGE) 1200 WATTS 4 OHM LOAD MIN. [. . . ] When designing your rack, put the heavier items at the bottom and the lighter items toward the top. Secure the front panel of the amplifier to the front of the rack using four screws with soft washers to prevent scratching the panel. In addition, because of the weight of the amplifier, you must secure the rear support brackets of the amplifier to the back of the rack. You could use a support rail or shelf across the back of the rack, or angle brackets attached between the rear support brackets and the rear rails of the rack. This is recommended for all components mounted in a rack that is going to be moved frequently (or thrown in the back of a pickup truck and transported down a bumpy gravel road to that outdoor festival!). AC POWER CONSIDERATIONS Be sure the M·1200/M·1400 is plugged into an outlet that is able to supply 120VAC at high current. If the voltage should drop below 116VAC, the M·1200/M·1400 will no longer be able to supply rated power. (It will continue to operate down to 50% of the rated voltage, but it just won't be able to reach full rated power. ) Be sure the AC outlet can supply enough current to allow full power operation of all the amplifiers plugged into it. The outlet should be a three-prong socket that matches the power cord. The AC current demand of an amplifier varies depending on several factors, including the crest factor and the duty cycle of the program material. Under typical conditions reproducing rock music where musical peaks are just below clipping, the M·1200/M·1400 will require the following average currents: Average Current Required 8A 5A 3. 2A THERMAL CONSIDERATIONS The M·1200/M·1400 amps are fan-cooled and bring air in through the front and out through the sides. Make sure that cool air is available at the front of the amplifier, and that there is room on each side for the warm air to exit from the amplifier and dissipate. If rackmounted, make sure there is room for the warm air to circulate around the side and out through the rear of the rack. In a typical rack, there will be a space of 1 to 2 inches on either side of the amplifier. The M·1200/M·1400's unique T-Design Constant Gradient Cooling Tunnel provides substantially better cooling for the output transistors than conventional designs that simply blow air through the chassis, getting dust and other contaminants over all the internal components. The Cooling Tunnel provides a shorter, more directed path so the cool air concentrates on the heat produced by the output devices. This results in increased reliability and longevity for the amplifier. Amplifier Loading 2 ohms per side or 4 ohms bridged 4 ohms per side or 8 ohms bridged 8 ohms per side or 16 ohms bridged Peak Current Required 25A 16A 10A It is recommended that a stiff supply of AC power be used because the amplifier places high current demands on the AC line. The more power that is available on the line, the louder the amplifier will play and the more peak output power will be available for cleaner, punchier bass. Having said this, we also realize that in many applications a standard 15A service may be all that is available. Under typical conditions, reproducing rock music where musical peaks are just below the clipping point, you can safely connect more than one amplifier to a 15A service. Use the table below as a guideline: Maximum Number of Amplifiers on a 15A Service 2 3 5 Amplifier Loading 2 ohms per side or 4 ohms bridged 4 ohms per side or 8 ohms bridged 8 ohms per side or 16 ohms bridged 23 The extension cord used to supply power to the "amp rack" should have a third wire safety ground to avoid presenting a safety hazard. We also recommend using a cord that has conductors large enough to avoid severely limiting the amplifier's ability to supply high currents on transients. With this in mind, we recommend using the following for a fully loaded 15A service: Extension Cord Length Wire Gauge 25 feet 14 AWG 50 feet 12 AWG 100 feet 10 AWG Power amplifiers can have momentary peak current requirements many times above the nominal average current draw. [. . . ] For instance, four 8-ohm speakers, connected in series, will equal 32 ohms (8 + 8 + 8 + 8 = 32). "Parallel" means that the positive amp output connects to the positive terminals of all the speakers, and the negative amp output connects to the negative terminals of all the speakers. If one speaker fails in a parallel configuration, the others will still work, but the load will change. That lets you breathe a little easier (the show will go on), except that you may have a dead speaker and not even know it. [. . . ]