Mackie M800 Owner's Manual - Page 11
Meters, Channel Status, Power - speed switch
View all Mackie M800 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 11 highlights
METERS The meters indicate the output level in decibels referenced to the clipping point of the amplifier. The top LED is labeled OL (short for Overload). OL OL If this comes on, the -3 -3 amplifier will start to distort, and the audio signals -6 -6 may "clip". -9 -9 Ideally, the -20, -9, -20 -20 -6, and -3 LEDs will light CH STATUS at normal signal levels, 1& 2 while the OL LED may NORM HOT blink occasionally during peak moments. If the OL (Overload) LED is blinking fre- quently or continuously, turn down the source signal (e.g. the mixer's master faders or the preamp gain). If this is not done, you may over- heat the amplifier and upset the neighbors. CHANNEL STATUS During normal operation, the NORM LED remains lit, indicating that temperatures within the M•800 are at a safe level. The internal 2-speed cooling fan will run at slow speed. If the internal temperature of the amplifier rises to 60°C, the fan kicks into high speed, moving more air through the amplifier to cool the output transistors. If the temperature rises to an unsafe level (85°C), the HOT LED lights and both outputs of the overheated amplifier will mute. The fan will remain running at high speed until the internal temperature drops to 60°C. When this occurs, the NORM LED lights, and the amplifier speaker outputs become active again. Be Aware: If the HOT LED comes on frequently, something is overworking the M•800 or it's not properly ventilated. Look at each of the conditions below and determine what is causing the amplifier to overheat. • Improper ventilation • High ambient temperatures • Overdriving the amplifier into clipping • Driving hard into low impedance loads • Frayed or partially shorted speaker cables • Defective or internally shorted speakers DO NOT BLOCK THE VENTILATION PORTS. The amplifier fan draws air from the front and out through the side panels. The amp needs plenty of fresh air to stay cool. The heaviest load the M•800 can tolerate is 2 ohms per channel (4 ohms in bridged mode). If you have a set of speakers wired in parallel, be sure the load isn't adding up to less than 2 ohms. Anything below 2 ohms can trigger the protection circuits. The NORM and HOT LEDs are only affected by the temperature, not by any other fault. POWER To make the amp operate, push the top half of the POWER switch. It clicks into place and a 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 turn on the M•800, a built-in delay circuit prevents any pops or thumps from being transmitted to the speakers. Although the delay will help, you should still follow these precautions: • When powering up your system, turn on the amplifiers last. • When turning off your system, turn off the amplifiers first. • Make sure that you turn down your signal source, mixer or preamp before you turn on the amplifier. • If you have multiple amps, you should turn them on one at a time. This will prevent blowing a circuit breaker if they all come on at the same time. 11