Mesa Rosette 300 Two:Eight, Руководство пользователя

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DISCUSSION ABOUT AMPS & CLASS D FROM THE DESIGN TEAM
QUESTION
What makes this new amplifier so small and light weight?
ANSWER
This amplifier uses new technology, both an SMPS (SwitchMode Power Supply) and a CLASS D power
amplifier to decrease the size and weight. These designs are carefully implemented and fully tested to insure robust, reliable
performance in real world conditions night after night
QUESTION
How can a light weight amplifier deliver solid bass? I was always told that an amplifier has to be heavy to produce
acceptable bass.
ANSWER
By operating in a non-linear fashion (with the power devices that are either fully on or fully off) the output
stages no longer have to accommodate reactive load inefficiencies, overly sensitive protection of “safe operating areas”, and
dissipate waste heat like output devices operating within the linear region. This means more power and better low frequency
control. In fact, the pro audio industry has been using SMPS and Class D almost exclusively in the large scale touring market
for about 10 years now, driving massive arena and stadium subwoofers night after grueling night on the road. In fact, much
of the technology in our power amplifiers comes from the high reliability touring pro audio world.
QUESTION
How do I know that these amplifiers will be reliable?
ANSWER
The design engineer of the ROSETTE
®
amplifier project has over 10 years of successful SMPS and Class D
amplifier experience, both in bass and acoustic amplifiers as well as in the touring pro audio world. We have worked closely
with the European engineering team on the development of these new power modules, including extensive testing, not just
in the lab, but real world testing on real stages with real musicians and real audiences, night after night.
QUESTION
Why is the power supply so small and light weight?
ANSWER
An SMPS is just like any other power supply, except for the fact that it operates at a much higher frequency
(typically around 80-100kHz) than a line frequency power supply (either 50Hz or 60Hz). The higher the operating frequency,
the smaller the power supply’s transformer core needs to be. Since most of the weight of a power transformer is in the core
(and the copper wire around the core), making the core smaller reduces size, weight and the amount of copper needed to
wrap around the core.
QUESTION
How does the SMPS work?
ANSWER
Without getting too technical, a switch-mode power supply takes the incoming AC mains (50-60Hz) power,
rectifies it to a high voltage direct current (HVDC). This HVDC is then filtered and stored in the input filter capacitors as reserve
energy for discharge as needed into dynamic loads. This HVDC is then chopped/switched at about 100kHz into a high volt-
age, high frequency alternating current (HVHFAC), which is then fed through a high frequency transformer which converts
the HVHFAC into low voltage, high frequency alternating current (LVHFAC) which is then rectified and filtered into low voltage
direct current (LVDC) that the power amplifier’s circuitry uses.
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