Toa A-903A, Operating Instructions Manual, Page: 1 / 15

1 6-channel mixer power amplifier
2 Wide frequency response; 20 — 20,000Hz, ±1dB
3 Low distortion and noise level
4 Excellent output regulation
5 Bass and treble controls
6 Bridging input/output
7 Signal processing input/output
8 Self-protect ing circuitry design
9 Varied output impedances; 4 and 8 ohms, 25 and 70 volts
10 A full range of plug-in modules
11 Portable or rack-mounting type
The TOA A-903A, A-906A and A-912A Mixer Power Amplifiers
control and mix up to six independent input signals. The A-903A
delivers up to 30 watts of output power, the A-906A 60 watts and
the A-912A 120 watts. Optional accessory modules are available for
use with the A903A, A-906A and A-912A to provide versatility for
a wide range of operating applications. Edge connectors on the rear
of the unit permit the selection of the TOA plug-in modules : The
H-01 series, H-02 series and H-03 series Microphone Preamplifiers,
the E-01 and E-11 Mag. Phono Preamplifiers, the X-01 series and
X-11 series Auxiliary Preamplifiers for high-level sources, the B-01
series and B-11 series Bridging Transformers for bridging high-
impedance lines, the L-01 series Line Matching Transformers for
matching 600-ohm lines, I-01 Paging Input for combining with TOA
Intercom Systems EXES-1000, EXES-5000 and EX-16, T-01 series
Line Outputs for matching 600-ohm lines and the S-01, S-02 and
S-03 Tone Signal Generators for generating attention-getting signals
and 1 kHz sine wave for testing within the total system. Other
features include a muting function. Sources fed to particular input
module accessories are muted by short-circuiting at MUTE
TERMINALS on the rears. To perform this function, Module E-11,
X-11 series or B-11 series is required.
The TOA A-903A, A-906A and A-912A Mixer Power Amplifiers
have output terminals to match 4- or 8-ohm speaker systems, or
speaker distribution systems may be connected to the 25- or 70-volt
terminals. The A-903A, A-906A and A-912A can be rack mounted
by using Rack-mounting Bracket accessories MB-921 (for A-903A)
or MB-931 (for A-906A and A-912A). The PF-911 Perforated Panal
(1.73 inches, 1 rack unit) accessory provides suitable ventilation,
finished in color to match the A-903A, A-906A and A-912A.
Toa Electric Co., Ltd.
KOBE, JAPAN
Operating Instruction Manual
TOA NEW 900 SERIES
MIXER POWER AMPLIFIER
A-903A
A-906A
A-912A
Features General Description