Mackie M1200 Owner's Manual - Page 15

soothing green light adjacent to it glows. To turn the amp off, push the lower half. It'll click again and the green light will extinguish. When you power up the M•1200/M•1400, a built-in delay circuit prevents any pops or thumps from being transmitted to the speakers due to turn-on instability in the system. Be sure the signal driving the amplifier is turned down when you first power up the system. There are few things as rude as 3 seconds of silence followed by 225 watts of full-blast stereo sound! (Well, maybe 225 kilowatts of accordian music...) If you shut down your system, turn off your amplifiers first. When powering up, turn on your amplifiers last. This way, equipment feeding the amp won't "pop" or "thud" when it's powered up or down. POWER CORD We all know what a power cord is. The M•1200 and M•1400 have big beefy cords built in. Plug the power cord into a 3-prong outlet that is capable of delivering 120VAC at 15 amps. For current-delivery purposes, the M•1200/ M•1400's voltage source (wall outlet, extension cords, or power strips) must be capable of continuously delivering 15 amps. And for safety reasons, that source must be a "3-prong" outlet with hot, neutral, and ground terminals. We're dealing with some bigtime electricity here - don't mess with it. See "AC Power Considerations" . SPEAKER OUTPUTS Some call them "GR" jacks, others call them "Banana" jacks, but we prefer to call them "Binding Posts." You can call them whatever you like (except late for supper). These terminals are your standard fare. To use the binding post outputs, you can terminate your speaker cables with single or double banana plugs, spade lugs, or leave them unterminated: Unscrew the amp's binding posts enough to reveal the holes on their sides, then insert your stripped wires (stripped about 3/8" back) into the holes and retighten the posts (finger tight is fine - please don't reef on them with a wrench!). Be careful that no runaway strands touch the chassis or other terminals. The red posts are labeled "+," which means positive. The black posts are labeled "-" for negative. You probably know the importance of getting these terms correct - if one side is hooked up "in phase" and the other side is "out of phase," you'll be "out of work." (By the way, although everyone says "phase" in this situation, the correct word is "polarity"... but it's not as much fun to say.) Using high-quality stranded speaker cable (16 gauge or thicker), connect the positive outputs of the M•1200/M•1400 to the positive inputs of your speakers, and the negative outputs to the negative inputs. The exception: If you're using the M•1200/M•1400 in BRIDGE mode, this does not apply. Please read on. Note (M•1200 only): In addition to the binding posts, the M•1200 also has 1/4" TS (tip-sleeve) SPEAKER OUTPUTS, so you can use speaker cables with 1/4" TS plugs. The tip is positive (+) and the shield is negative (-). They're wired in parallel with the binding posts and behave exactly the same (except they can't be used in BRIDGE mode). 1 CHANNEL / BRIDGE / MONO LOW CUT INPUT FILTER TYPICAL 35 Hz BALANCED OR UNBALANCED STAGE MONITOR 100 Hz OFF 170 Hz CONSTANT DIRECTIVITY HORN EQ /AIR EQ 4.5 kHz ON 2k Hz 5.6k Hz AIR EQQ OFF TYPICAL THRU AMP MODE STEREO TYPICAL MONO BRIDGE OUTPUT APPLICATION FULL RANGE LIMITER (CH1 & CH2) STEREO TYPICAL SUB WOOFER FREQUENCY 125Hz ON OFF 63Hz INPUT BALANCED OR UNBALANCED 2 CHANNEL LOW CUT FILTER TYPICAL 35 Hz STAGE MONITOR 100 Hz OFF 170 Hz CONSTANT DIRECTIVITY HORN EQ /AIR EQ ON 4.5k Hz THRU OFF TYPICAL 2k Hz 5.6k Hz AAIR EQ 15