MACKIE M3000 - Manual (Page 16)

16
M-Series
M-Series
General Precautions and Considerations
AC Power Considerations
Be sure the amplifier is plugged into an outlet that
is able to supply the correct voltage specified for your
model.
If the line voltage should drop below about 97% of
the rated voltage, the amplifier will no longer be able to
supply rated power. (It will continue to operate down to
65% of the rated line 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 socket that matches the
power cord.
WARNING: Bypassing the plug’s
ground pin can be dangerous. Don’t
do it!
The AC current demand of an amplifier varies depend-
ing 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-Series amplifiers require
the following average currents:
Average
Current
M•2000 Amplifier Loading Required
120V 240V
2 ohms per side or 4 ohms bridged 8.6A 4.3A
4 ohms per side or 8 ohms bridged 5.6A 2.8A
8 ohms per side or 16 ohms bridged 3.7A 1.9A
M•3000 Amplifier Loading
120V 240V
2 ohms per side or 4 ohms bridged 11.1A 5.6A
4 ohms per side or 8 ohms bridged 7.4A 3.7A
8 ohms per side or 16 ohms bridged 4.8A 2.4A
M•4000 Amplifier Loading
120V 240V
2 ohms per side or 4 ohms bridged 14.2A 7.1A
4 ohms per side or 8 ohms bridged 9.3A 4.7A
8 ohms per side or 16 ohms bridged 6.0A 3.0A
Rack Mounting
The M-Series amplifiers require two rack space units
(2 IU = 3.5"). The M•2000 requires 17.0" depth inside
the rack, including the rear supports. The M•3000 and
M•4000 require 19.5" depth inside the rack, includ-
ing the rear supports. 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 brack-
ets 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 recom-
mended 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!).
Thermal Considerations
The M-Series amplifier is fan-cooled and brings air in
through the rear and out through the front. Make sure
that cool air is available at the rear of the amplifier, and
that there is room at the front for the warm air to exit
from the amplifier and dissipate. If rack-mounted, make
sure the amplifier is not pulling warm (or hot) air in
from the rack.
The M-Series amplifier’s unique Constant Thermal
Gradient heatsinks provide substantially better cool-
ing for the output transistors than conventional de-
signs that simply blow air through the chassis, getting
dust and other contaminants over all the internal
components. The heatsinks contain a cooling tunnel
that provides a shorter, more directed path for the air,
with the air moving faster toward the end of the tunnel
to balance the temperature along the entire length of
the heatsink. This results in increased reliability and
longevity for the amplifier because the output transis-
tors are kept cooler.