Introduction - Toa A-503A Manual

TOA Electronics Amplifier Guide
Welcome to the TOA Amplifier Guide!
TOA has been providing complete sound systems since 1934. After our first U.S. sales office was estab-
lished in 1974, our TA-900 Series mixer/amplifiers quickly gained recognition for their unmatched
combination of flexibility, reliability, and performance. Since that time,TOA has steadily expanded and
improved our line of amplifiers, mixer/amplifiers, and associated electronics. The TOA 900 Series, now
in its 3rd generation of product design, is renowned for its flexible modular architechture, elegant sim-
plicity of operation, and bulletproof reliability. The new BG-M Series builds further on our tradition by
offering the flexibility of a module port in a package that is remarkably affordable without sacrificing
either performance or reliability. With six distinct series of amplifiers and mixer/amplifiers to choose
from, plus a range of mixers, signal processors, and now network audio, TOA offers the most compre-
hensive line of audio electronics for systems contractors.
The TOA Amplifier Guide is a sound system design tool aimed at helping system designers, sales staff,
installers and end users select the right amplifiers and accessories for their applications. It includes a
review of the basic concepts of audio amplification, such as signal flow, levels, and impedance, plus
useful references such as thermal dissipation, power consumption and line loss charts, as well as tips
for troubleshooting (including impedance measurement). Further information on speaker system
design and speaker selection and placement may be found in the TOA Speaker Guide, available for
download at www.toaelectronics.com.
Disclaimer: This design guide does not cover all of the general concepts underlying sound system design
and installation, which would require several hundred pages. This guide is not meant to replace the par-
ticipation of an experienced consultant or engineer.
References: For more in-depth coverage of sound system design principles, we recommend the fol-
lowing two excellent books:
Sound System Engineering, Second Edition, Don & Carolyn Davis, 1975, 1987 by Howard Sams & Co.
ISBN: 0-672-21857-7
Handbook for Sound Engineers:Third Edition, Glen Ballou, Editor, 2001, Butterworth & Heinemann. ISBN:
0-240-80454-6
Acknowledgements
Thanks to Steve Mate, Lucas Marciniak, and Martin Gonzalez in the TOA Product Support Group for
their invaluable support and contributions to this project, and to Geraldine Vargas for designing the
layout. This guide is dedicated to the memory of my late father, whose amp-building projects on the
kitchen table gave me a love for the smell of solder, and whose demonstrations of loudspeaker sensi-
tivity gave me a love for the art of sound system design.
David Menasco
Product Application Specialist
TOA Electronics, Inc.
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