Installation; Mounting; Cooling; Operating Voltage - Martin Audio MA4.2s User Manual

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CONTENTS
threshold can be adjusted for a much higher current, so it cannot interfere with the requirement by the loudspeaker
impedance curve.
6

INSTALLATION

6.1

Mounting

The amplifier is two rack units high (2U) and weighs 10Kg (22lbs) and will mount in a standard EIA 19" rack.
Amplifiers may be stacked directly on top of each other. There is no need for spacing between units. If it is the
intention to fill a rack with amplifiers, we recommend racking is started from the bottom of the rack. It is also
recommended that rear supports are used for amplifiers mounted in the middle of the rack, especially if used as
part of a portable system.
6.2

Cooling

Your amplifier uses a forced air cooling system to maintain a low and even operating temperature. All fan cooled
Martin Audio MA series amplifiers have front to rear cooling. Never try to reverse the direction of airflow, as the
amplifier needs a pressure chamber between the fans and the internal heat sink and this only operates in one
direction of the airflow.
Make sure there is adequate air supply in front of the amplifier, and that the rear of the amplifier has sufficient
space to allow the exhaust air to escape. If the amplifier is rack mounted, do not use covers or door on the front or
rear of the rack. If the heat sink temperature rises too high, sensing circuits will mute the hot channel. If the power
supply overheats, another sensing circuit will mute both output channels, until they cool down to a safe operating
temperature.
For installations with a central cooling system, usually found in fixed installations with a dedicated rack room, it may
be necessary to calculate the maximum heat emission. Refer to Power consumption on page 11. Remember never
rack different brands of amplifiers together that have opposing air flow characteristics.
6.3

Operating voltage

WARNING!
A label just below the mains cable inlet on the rear of the amplifier indicates the selected AC mains
operating voltage. Connect the mains cable only to the AC source referred to on the label. The warranty
will not cover damage caused by connecting to the wrong type of AC mains.
If th e fitte d m ains co nn e ctor is n ot ap prop ria te fo r yo u r co u ntry, it ca n b e cu t o ff an d wired to a suitab le co nn ector in
the follow in g w ay:
B LA CK o r B RO W N
W HITE o r B LU E
G RE EN o r G RE E N/YE LL O W
O nce co n ne cte d to a su ita ble AC su pp ly, the am plifier ca n be starte d w ith the p o we r switch. Wh en yo u po w er u p the
a mp lifie r it ta ke s a cou p le o f secon d s to se lf ch eck (this is kn ow n a s the "so ft sta rt" or "slo w sta rt" seq u en ce ), th e fan s
the n blo w at high sp ee d b efore g oing in to "idle". T he tw o bo tto m gre en L E D's th e n illum in ate to sho w th e a mp lifie r is
o pe ra tio na l.
6.4

Denmark:

National deviation concerning installation of the MA4.2s:
Danish safety regulation only permits the use of an 8A main fuse. As the MA 4.2s uses an internal primary mains
fuse of 15A, the MA4.2s must be equipped with an industrial mains connector rated for 16A or above, or as an
alternative it can be hard wired to a 16A capacity circuit and breaker.
6.5

Switzerland:

National deviation concerning installation of the MA 4.2s:
Swiss safety regulation stipulates that type 23 mains connectors must be used.
All material © 2007. Martin Audio Ltd. Subject to change without notice.
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Martin Audio – MA4.2s Amplifier
10
GUIDES