MACKIE FRS1700 - Manual (Page 11)

11
Owner’s Manual
Owner’
s Manual
General Precautions
AC Power Requirements
The amplifier's power cord should be plugged into an
AC outlet properly configured with the voltage required
for your particular model.
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 safety ground
pin can be dangerous. Don’t do it!
The AC current demand of an amplifier varies
depending on several factors, including the load
impedance, 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 amplifiers require the following average currents:
FRS•1700 = 8 A
FRS•2800 =11 A
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.
If more than one amplifier is sharing an AC outlet,
avoid turning them all on at the same time. Rather,
sequence them on, one at a time, to prevent popping
the circuit breaker (due to in-rush current).
Thermal Considerations
The power amplifier is fan cooled. Air is drawn
through the rear panel vents to cool down the
amplifier heatsinks and then expelled through the
front panel vents.
When installing, be sure to allow sufficient air space
around the front and rear of the amplifier for adequate
cooling for the heatsinks. Leave at least one rack space
above and below, and at least six inches behind and in
front of the chassis to allow proper ventilation.
If the amplifier should overheat, a thermal switch
turns off the power amplifier, allowing the heatsink
to cool down. Once the amplifier has cooled to a safe
operating temperature, the thermal switch resets and
reactivates the amplifier. If this should occur, identify
the cause of the problem and take corrective action.
For example:
• Provide better ventilation
• Install a fan in the rack to move more air
• Make sure the amplifier is not overloaded with
too low of a load impedance or by a short circuit
on the speaker line
Rack Mounting
The FRS amplifiers are designed to be mounted in
a standard 19 inch rack. They require two rack spaces
(2U = 3.5"). They also require 14.7" depth inside
the rack, including the rear support brackets. When
designing the 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 rails and the rear rails of the rack. This
is recommended for all components mounted in a rack
that is going to be moved frequently.
Maintenance
Usually, the amplifier will not require regular
maintenance for normal use. However, you can do
several things to keep it in good operating and
cosmetic condition.
• Testing: Periodically test the system for
proper performance. A simple test is to play
a CD through it using well-defined, articulate,
wide-range program material. Listen to ensure
all drivers are working properly and for any
evidence of distortion or other extraneous
sounds. Test at several volume levels: very
low, normal, and high.
• Cleaning: Use only a clean dry cloth to dust off
and clean the surface. Turn off the power to the
amplifier while you do this.