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Operation Instruction Manual

TOA NEW 900 SERIES

MIXER PREAMPLIFIER 

M-900A

1 6-channel 

mixer 

preamplifier

2  Wide 

frequency 

response; 20 — 20,000Hz, ±1dB

3 Low 

distortion 

and 

noise

4 Parallel 

operation of two mixer preamplifiers

5 Headphone 

output

6  Bass 

and 

treble 

controls

Tone defeat switch

8 Output 

on-off 

switch

9 VU 

meter 

range 

switch 

(selectable  4dBm/18dBm)

10  A 

full 

range 

of 

plug-in 

modules

11 Balanced  

and 

transformer-isolated output of 150/600 ohms

12 Portable 

or 

rack-mounting type

The TOA M-900A Mixer  Preamplifier  controls and  mixes  up to  six

independent  input  signals and delivers up to +20dBm of output

power. Optional plug-in modules are available for use with the M-

900A to provide versatility for a wide choice of operating applica-

tions.  Edge connectors  in the  rear of the unit permit selection from

a  wide  range of 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 for magnetic  phono  inputs, 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, the  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  Generators for generating attention-getting signals

and  1kHz sine wave for testing within the total system. Sources fed

to particular input module accessories are muted by short-circuiting

at  MUTE TERMINAL on the rear. To perform this function,

Module  E-11,  X-11 series or B-11 series is required.

The TOA M-900A Mixer Preamplifier has a balanced and trans-

formerisolated  output for operation with 600-ohm or  150-ohm

loads.

Other features  include  a tone defeat  switch,  an output on/off

switch, connections for parallel coupling of another  M-900A or

Mixer  Power  Amplifiers  A-903A,  A-906A or A-912A, and  monitor-

ing by visual  and/or audio  means.

Toa Electric Co., Ltd.

KOBE, JAPAN

1 3 3 - 0 2 - 7 3 6 - 1

Printed in Japan

Features

General Description

Summary of Contents for M-9000

Page 1: ...or magnetic phono inputs 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...

Page 2: ...if the output level is 18dBm Usually set the switch to 4dBm position since the amplifier s rated output is 4dBm Place it in 18dBm position when more output is provided Item Name Function Description...

Page 3: ...and X 21 modules employing volume remote control functions connecting a potentiometer 10k ohms to the terminal of any of these modules permits the sound volume to be remotely controlled by means of t...

Page 4: ...NE QUALITY When adjusting tone quality place the TONE SWITCH in IN position thus activating the BASS and TREBLE CONTROLS Each control provides frequency response characteristics of flat in center boos...

Page 5: ...on receipt of the amplifier shipment please inspect for any damage incurred in transit If damage is found please notify your local TOA representative and the transportation company im mediately State...

Page 6: ...Block Diagram M 900 A 5...

Page 7: ...30 mW to 600 ohms 200 mW Aux Balanced 10k ohms 2 dBm Less than 1 5 dB no load to full load Master volume min 90 dB Master volume max 77 dB Bass 10dB at 100 Hz Treble 10dB at 10 kHz 6 Input gain contr...

Page 8: ...ith TOA INTERCOM SYSTEMS It accepts paging signals from the intercom station A group of special signal generating modules is also available for catching attention before announcement and testing withi...

Page 9: ...dB oct max attenuation MUTE DELAY CONTROL I 01S HIGH CUT FILTER CONTROL 4 2kHz 6dB oct max attenuation This provides flat characteristics at full CW position and attenuation in low frequency by turnin...

Page 10: ...Block Diagrams Plug in Modules 10...

Page 11: ...trol of the corresponding input so that an appropriate sound level may be obtained through the remote volume control T 01 SERIES BALANCED 600 ohm LINE OUTPUT MODULES This series of modules of rated ou...

Page 12: ...nd T Lines R line Approx 9mA DC plus audio signals of 30dBm max T line Approx 9mA DC Rack mounting Brackets Perforated Panel Silver Silver PF 911 MB 931A MB 921A A 912A A 903A P 906A P 912A P 924 HOW...

Page 13: ...Schemiatic M 900 A...

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