9
DESIGN FEATURES
Cooling
MARTIN AUDIO MA Series amplifiers run very cool due to a patented heat
exchanger. The bi-polar output devices are mounted directly onto a copper
heat sink thereby avoiding thermal losses normally found when using mica
washers. The heat sink is mounted horizontally in front of a pressure
chamber and the air flow is constant along the whole heat sink. When cool
air hits the geometric fins of the heatsink, turbulence is produced thereby
enabling efficient cooling. (In a conventional tunnel design the end of the
heat sink away from the fan invariably gets hotter than that directly in front of
the fan).
Light weight
The MA 2.8 switch mode amplifier has a very good power to weight ratio,
(280w/Kg) making it one of the most powerful, lightweight 2u amplifiers
available. This is achieved not only by the design of the power supply and
heatsink but also by the use of an alloy chassis making rear rack supports
unnecessary in most applications.
Switch mode power supply (SMPS)
Switch mode power supplies are the modern solution to the problems of size
and weight. However, early examples of SMPS used in power amplification
were not ground breaking and literally adopted the type of supply found in
many computers today. The MARTIN AUDIO SMPS is different in that it is
regulated.
Whilst the SMPS may sound complex it is actually very straightforward with
high reliability. The net result is good bass and fast response. Because the
supply is regulated, the power amplifier will produce the same power output
even if the AC line voltage falls by more than 20%!
Efficiency is also assured, and in the case of the MA2.8 this is especially
apparent; its power supply draws only 4kW and yet it produces 2 x 1400W.
(See figure 14).
Martin Audio – MA2.8 Power Amplifier
E
NGLISH
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