User Manual

2
1. About EEEngine
1.1. Introduction
Yamaha Power Amplifier Philosophy
Our approach to manufacturing power amplifiers is
simple; pure and natural amplification of the input signal.
Mixed audio is sent to the amplifier from the mixing
console, to be amplified before final “coloring” or
“flavoring” through the loudspeakers. The role of
amplifiers in a sound system should not be to add its
own color, but to be faithful to the input signal to give
you maximum control over the final sonic performance.
[ Fig.1 ] The input signal, 70Hz burst sine wave.
[ Fig.2 ] Output signal of a typical competitor amplifier.
[ Fig.3 ] Output signal of Yamaha T5n amplifier; Natural and true to the input
Reliability is another important feature of Yamaha
amplifiers. All Yamaha products are also tested under
severe conditions and must comply with Yamaha’s strict
quality assurance standards. Read more about Yamaha’s
quality assurance testing and standards at:
http://www.yamahaproaudio.com/topics/leading_technol
ogy/quality_control/index.html
1.2. Explanation of different amplifier
topologies
There are many different amplifier topologies, or circuit
design principles that are used in professional power
amplifiers. The majority of the high power amplifiers
seen in the professional audio industry today can be
classified as derivatives of three major technologies;
Class H, Class D or a hybrid of Class AB and Class D
such as Yamaha’s EEEngine (Energy Efficient Engine).
Class AB
Class AB technology is the foundation of professional
amplification. Even to this day, Class AB amplifiers can
be found in many professional audio applications. This
topology, which had been the norm in the industry for
decades, offers a simple circuit configuration and superb
sound quality. Yamaha’s older amplifiers such as P2200
released in 1976 and PC2002M, released in 1982 were
Class AB amplifiers. Class AB topology, however, has a
drawback of always requiring its output stage to drive at
maximum voltage output, resulting in a great deal of
heat dissipation. This low efficiency is the reason why
Class AB amplifiers are comparatively limited in output
power considering their unit size and weight. When