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MA Amplifier • Operating Manual
2.5
Mechanical
Each amplifier model is 2RU and is designed to
fit into a 19-inch equipment rack with minimum
depth of 16.1" (409mm). Use four screws
when mounting the amplifier to the front rack
rails. Rear support is recommended for mobile
or touring use. In some installations where the
sound system is exposed to a high level of RF
noise or system-induced oscillation, it may be
necessary to ground the amplifier's chassis
to the rack enclosure. This is accomplished
using star type lockwashers on the four
rack mounting screws, placed between the
amplifier chassis and the rack rails. These star
washers will penetrate through the amplifier
and rack rail finish to adequately ground the
chassis to the rack.
2.6
Cooling
Air vents on the amplifier front, back, and side
panels must have access to free flowing room
temperature air. Cool air is drawn in through
the front panel and blown out through the
rear panel. It is not necessary to leave empty
rack spaces above or below the amplifier. See
specifications
for amplifier thermal output
characteristics in BTU/hr.
3
Amplifier Protection
Power-On Delay: All models have a two second
turn-on delay to prevent excessive in-rush
current when first powered on.
Thermal Protection: Cooling fans are
continuously variable, reaching their maximum
speed when an amplifier channel reaches 80%
of it's safe operating temperature. Temp LEDs
turn on when signal limiting countermeasures
are being applied to that channel due to over
temperature conditions.
Overpower Protection: To protect internal
components against overpower conditions,
a protection scheme in each output stage
reduces audio output power until the fault
condition is no longer present.
Output DC and Rail Fault Protection: Output
DC on any channel will trigger the Protect LED
and mute that channel.
AC Mains: If the AC Mains line voltage exceeds
or falls below the specified operating range,
the amplifier will temporarily shut down. It will
automatically restart as soon as the AC line
voltage returns to the specified range.
For details on these and other amplifier
protection schemes, plus their LED codes, refer
to the
troubleshooting
section.
6