TOA Electronics W-906A, W-912A 1. GENERAL DESCRIPTION, 2. FEATURES

1. GENERAL DESCRIPTION

The TOA W-906A and W-912A Mixer Power Amplifiers control and mix up to six independent input signals

plus two inputs with use of expanding kit. The W-906A delivers up to 60 W of output power and the W-912A

120 W. Optional accessory modules are available for use with the W-906A and W-912A to provide versatility

for a wide range of operating applications. Edge connectors at the bottom of the front panel permit the

selection of the TOA plug-in modules: The H-01 series, H-02 series, H-03 series, H-21 and H-22 Microphone

Preamplifiers, the E-01 series and E-11 series Mag. Phono Preamplifiers, the X-01 series, X-11 series and X-

21 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 Ωlines, 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 Ωlines 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 front. To perform this function, Module E-11, X-11 series or B-11 series is required. Using

any of the modules H-21, H-22 and X-21 permits the input signal level to be controlled remotely by means of

an external potentiometer.

The W-906A and W-912A have a built-in one-octave graphic equalizer with 9 bands to tailor sound system

frequency response to room acoustics, reducing feed-back tendencies and improving intelligibility. A built-in

compressor circuit is provided to protect the output level from distortion as a result of excessive input and

keeps it constant. Compressor's threshold level can be adjusted.

The W-906A and W-912A Mixer Power Amplifiers have output terminals to match 4 or 8 Ωspeaker systems,

or speaker distribution system may be connected to the 25 or 70 V terminals. User's (blank) space is provided

for additional functions to be made by the customers. The expanding kit (optional) may be loaded in this space

when the number of input is increased. Protection against tampering is assured by means of a key-locked

hinged door. The W-906A and W-912A can be mounted in any four-inch wall with of the BX-9F Flush

Mounting Black Box. On-wall mounting is also possible with the BX-9S Surface Mounting Box.

• 6-channel mixer power amplifier

• Expandable to 8-input

• Output power: 120 W for W-912A, 60 W for W-906A

• Wide frequency response: 30 to 20,000 Hz ±1dB

• Low distortion and noise

• Excellent output regulation

• Built-in one-octave equalizer

• Built-in compressor

• Self-protection circuitry design

• Separate output terminals: 4 and 8 Ω, 25 and 70 V

• Extra space for customizing

• LED pilot light

• LED peak indicator

• Full range of plug-in modules

• Flush and surface mounting