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GENERAL PRECAUTIONS AND CONSIDERATIONS
AC POWER CONSIDERATIONS
Be sure the M•1400i is plugged into an out-
let that is able to supply 120VAC at high
current. If the voltage should drop below
116VAC, the M•1400i 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.
WARNING:
Bypassing the plug’s ground pin
can be dangerous. Please don’t do it.
The AC current demand of an amplifier var-
ies 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•1400i requires the following
average currents:
RACK MOUNTING
The M•1400i amp requires two rack space
units (2U = 3.5"). It also requires 16.25" depth
inside the rack, including the rear supports.
When designing your rack, put the heavier
items at the bottom and the lighter items to-
ward 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 ad-
dition, 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 compo-
nents 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•1400i amp is fan-cooled and brings
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 am-
plifier and dissipate. If rack-mounted, 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.
This is adequate to allow the warm air to exit
from the amplifier.
The M•1400i’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 con-
centrates on the heat produced by the output
devices. This results in increased reliability
and longevity for the amplifier.
Average
Peak
Current
Current
Amplifier Loading
Required
Required
2 ohms per side or 4 ohms bridged
8A
25A
4 ohms per side or 8 ohms bridged
5A
16A
8 ohms per side or 16 ohms bridged
3.2A
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 ampli-
fier will play and the more peak output power
will be available for cleaner, punchier bass.
We 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
Amplifier Loading
on a 15A Service
2 ohms per side or 4 ohms bridged
2
4 ohms per side or 8 ohms bridged
3
8 ohms per side or 16 ohms bridged
5
Due to in-rush current, however, you should
avoid turning them all on at the same time.
Rather, sequence them on, one at a time, to
prevent popping the circuit breaker.
