Toa M-9000 Administrator Guide

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
7 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.
ToaElectricCo.,Ltd.
KOBE, JAPAN
133-02-736-1
Printed in Japan
Features
General Description

Item
Name
Function/Description
1
POWER ON-OFF
SWITCH
Applies line power. Two-position
pushbutton switch for on-off modes.
2
METER
Indicates the output level of the
amplifier. At rated output, it shows
0 VU (continuous sine-wave signal
input).
When power is turned on, meter
illuminates.
3
INPUT VOLUME
CONTROLS
Adjust gain of INPUT #1-#6
respectively.
4
BASS CONTROL
Adjust bass response.
Turn clockwise (CW) to boost and
counterclockwise (CCW) to
attenuate the bass response. Tone is
flat at center.
5
TREBLE
CONTROL
Adjust treble response.
Turn CW to boost and CCW to
attenuate the treble response. Tone is
flat at center.
6
TONE SWITCH
Selects IN/DEFEAT of the BASS and
TREBLE CONTROLS. When this
button isdepressed
the BASS
and TREBLE Controls are active.
When pressed again
they
become inactive to make tone flat.
(DEFEAT)
7
MASTER
VOLUME
CONTROL
Adjusts overall gain of unit.
8
OUTPUT SWITCH This is an output ON/OFF switch.
When pressed output signal is
obtained at the output terminal.
When pressed again no output
signal is obtained.
9
HEADPHONE
JACK
Connects to headphones with
impedance of more than 8
10
HEADPHONE
VOLUME
CONTROL
Adjust the volume for headphones.
Turn CW to increase.
11
VU RANGE
SWITCH
Selects meter-sensitivity.
When set to "4dBm" position, the
meter shows 0 VU if the output level
of amplifier is +4dBm. When set to
"18dBm," it shows 0 VU 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
1 AC POWER
SUPPLY CORD
Connects to power source.
2
AC OUTLET
(Unswitched)
Provides AC power for auxiliary
equipment with power consumption
of up to 500W.
3
AC FUSE
(250V 0.3A)
Protects amplifier from excessive
current drain. Replace only with
same type fuse. Refer to qualified
service personnel if fuse blows
repeatedly.
4
OUTPUT
TERMINALS
Connect to power amplifier(s).
5
MODULE INPUT
PORTS
Accept PLUG-IN MODULES which
are optionally available. Choose the
desired modules according to
application.
6
AUX OUT
Serves as a sub-output for connecting
other equipment having input
impedance of more than 10k such
as a tape recorder.
7
BRIDGING
INPUT/OUTPUT
This terminal is used as a mixing bus.
Mixing is achieved when the similar
terminal of another amplifier is
connected to this terminal.
The output level taken from this
terminal is independent of the
MASTER VOLUME CONTROL,
BASS and TREBLE CONTROLS, so
that the terminal can also be used as
recording output. The input
impedances of the equipment to be
connected here should be 10k or
higher.
8
MUTE
TERMINAL
With modules employing muting
function, which are optionally
available, the input signals fed to the
modules are muted by short-circuiting
at this terminal.
9
EARTH
TERMINAL
Normally connects to a record
player's ground.
Front Panel Controls and Features
Rear Panel Controls and Features
—1 —

•
This amplifier has six INPUT PORTS for PLUG-IN MODULES.
Select the desired ones for each application.
•Plug the modules into INPUT PORTS, sliding them between the
guide rails, and secure each with two screws.
•When not all INPUT PORTS are occupied, cover the vacant
PORTS with blank panels, and secure them with screws.
•PLUG-IN MODULES are provided in the following:
Balanced low impedance microphone
preamp module (with presettable low-cut
filter, high-cut filter and gain controls)
Balanced low impedance microphone
preamp module (with presettable low-cut
filter and gain controls)
Equalized mag. phono preamp. module
(with presettable gain control)
Unbalanced high impedance auxiliary
preamp module (with presettable
gain control)
Balanced 10k
Balanced 600
bridging transformer module
line matching
transformer module
Balanced paging input module
(with presettable gain control and MUTE Delay)
Balanced 600
line output module
(with presettable gain control)
Signal tone generator module
(with presettable output level control)
1 kHz sine wave
Yelp and buzzer
One-tone chime and continuous one-tone chime
H-01, H-21, H-31
H-02,H-22, H-32
E-01 , E-11
X-01, X-11, X-21
B-01, B-11
L-01, L-11, L-41
I-01
T-01
S-01
S-02
S-03
*With H-21, H-22 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 the connected potentiometer.
* H-31 and H-32 modules incorporate muting functions. If a switch
is connected to MUTE TERMINAL on the rear panel of the ampli-
fier and closed, these input signals can be passed through. When
the switch is opened, the input signal is muted.
*E-11 , X-11 , B-11 and L-11 modules incorporate muting functions.
If a switch is connected to MUTE TERMINAL on the rear panel
of the amplifier and closed, these input signals can be muted.
*L-41 incorporates signal activated muting function. Incoming
input signal causes mute terminal to be grounded.
* T-01 is used to feed out mixed signals to external equipment.
*T-01 should be inserted only in INPUT PORT #5 or #6.
(See PLUG-IN MODULES for details)
•
Connect power amplifier(s) to the output terminal of M-900A.
Select 600
or 150
connection, provided at the output ter-
minal, to match the input impedance of amplifier(s).
•
AUX OUT
For this connection, use a Phone Plug (Double pole) with two-wire
shielded cable.
600-ohm Connection
Strap terminals 2 and 3 .
4
3
2
1
GND
Hot
Common
Earth
150-ohm Connection
4
3
2
1
GND
Hot
Common
Earth
Strap terminals 1 and 2 , 3 and 4 .
Hot
Common
Earth
Input Connections
Output Connections
External equipment such as
tape recorders, etc.
—2 —

When all connections are completed, turn power switch on. Then,
the meter is illuminated. Approximately 5 seconds after switching
power on, the M-900A comes into operation.
VOLUME CONTROL
Set VU RANGE SWITCH to "4dBm" position and place OUTPUT
SWITCH in "ON" position. While observing the deflection of the
meter, control each input volume and master volume controls to
obtain a proper output level.
The swinging range of the pointer on the meter is recommended to
be within the range as indicated in the drawing. Also, adjust gain
(volume control) of the connected power amplifier to obtain similar
reading on the meter of the power amplifier.
In connecting a power amplifier with lower gain, so that the
mixer preamplifier is required to be used with its higher output,
the VU RANGE SWITCH shall be set to 18dBm.
ADJUSTMENT OF TONE 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, boost in CW and attenuation in CCW positions.
When tone controls are unnecessary, place the TONE SWITCH
in "DEFEAT" mode.
MONITOR
Monitoring is possible by the use of headphones.
Connect the headphones to HEADPHONE JACK, and adjust the
monitoring level by using the HEADPHONE VOLUME CONTROL.
OUTPUT ON/OFF SWITCH
ON/OFF status of the output can be controlled by the OUTPUT
SWITCH, and output can be obtained at the output terminal and
auxiliary output jack after confirming the content of the signal by
monitoringwithheadphones.
•
Do not block cover ventilation holes.
•The M-900A should not be placed in areas;
1 with poor ventilation.
2 exposed to direct sunlight.
3 with high ambient temperature or adjacent to heat-generating
equipment.
4 with high humidity or dusty levels.
5 susceptible to vibration.
Operation Installation
— 3 —

To mount the M-900A in a standard 19-inch equipment rack, use
the MB-921 Rack-mounting Bracket accessory.
Remove 4 screws securing case.
MB-921 (Silver)
(OPTION)
Fix the MB-921 with attached 4 screws.
The length of the screws should not
exceed 12mm (1/2 inches).
•
Unpacking
Upon 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 date, nature of damage, whether any damage was noticed on
the shipping container, prior to unpacking. Please give waybill
number of shipping order.
•
Failure
Should amplifier fail, contact your nearest TOA authorized con-
tractor or service center.
Rack Mounting
Servicing
— 4 —

Block Diagram M-900A
— 5 —

Type
Output Power
Power Band Width
Frequency Response
Total Harmonic Distortion
Inputs
InputSensitivity/Impedance
Outputs
Output Regulation (1 kHz)
Signal to Noise Ratio
(Band Pass 20 - 20,000 Hz)
Tone Controls Centered
Tone Controls
Controls
Indicator
Protection
Connectors
Power Consumption
Temperature Range
Dimensions in mm (inches)
(high) x (wide) x (deep)
Weight (without input modules)
Color
Standard Accessories
Other Features
6-channel mixer preamplifier
+4 dBm (Rated Output) +20 dBm (max.)
30 - 20,000 Hz +20 dBm 0.5% THD
25 - 20,000 Hz +18 dBm 0.3% THD
20 - 20,000 Hz, ±1 dB
0.01% at 1kHz, +20dBm output
Six Input Ports Each port accepts any input module
except T-01. Use T-01 only in port #5 or #6.
One Bridging Input/Output
Input Ports #1 to #6 : 100 mV/10k ohms
Bridging Input/Output: 100 mV/3.3k ohms
Main : Balanced, 150/600 ohms
Phones. Unbalanced, 8 ohms (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 controls 1 Master gain control
1 Bass tone control 1 Treble tone control
1 Headphone volume control
1 Output ON/OFF switch 1 VU meter range switch
1 Tone defeat switch 1 Power ON/OFF switch
1 Illuminated VU meter
Self-protection, with 1 AC fuse
Inputs #1 to #6
Bridging
Output
Headphone
Aux out
Mute
AC outlet
AC Power cord/plug
Card-edge connector
RCA phono jack
Screw terminal strip
Phone jack
Phone jack
2P socket
3-pin grounding type
SJT, 3-prong type
AC 120 volts, 60 Hz, 1 3 watts
-10°C to +60°C (12°F to 140°F)
101 (3.98") x 420 (16.54") x 265 (10.43")
Rack-mounting space size "2U" (3.46")
4.4kg(9.7Ibs.)
Silver
2 Volume control covers
1 Mute terminal plug
Output disconnected for approx. 5 sec after switching power on
Muting Function:Accomplished by model E-11, X-11, B-11
* Specifications are subject to change without notice.
Specifications M-900A
— 6 —

TOA NEW 900 SERIES
(OPTION)
The TOA PLUG-IN MODULES are suitable for TOA 900 SERIES
MIXER POWER AMPLIFIERS A-901A, A-903A, A-906A, and
A-912A MIXER PREAMPLIFIER M-900A, and POWER AMPLI-
FIERS P-906A, P-912A and P-924. Owing to wide selection of
MODULES, the desired applications will be obtained. The various
types of connectors can also meet the needs of equipment to be
connected. MICROPHONE PREAMPLIFIER H-01 series, H-21 and
H-31 incorporates controls for high-cut, low-cut and gain, H-02
series, H-22, H-32 and H-03 series controls for low-cut and gain.
A gain control is built in MAG. PHONO PREAMPLIFIERS E-01
and E-11 series, AUXILIARY PREAMPLIFIERS X-01 and X-11
series and X-21, PAGING INPUT I-01 and LINE OUTPUT T-01
series. T-01 series is an output module with transformer, serving
as a line output for recording, etc..
PAGING INPUT I-01 is specially designed to associate with 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 within the total
system. ALL PLUG-IN MODULES have handles on their front for
easy insertion and removal.
Features:
1. Wide dynamic range
2. Low noise and distortion
3. Wide frequency response
4. Built-in remote volume control circuit (available for models
having 20's in its model number such as H-21)
5. Built-in muting circuit to mute incoming signal when MUTE
TERMINAL is grounded. (available for modules having 10's in
its model number such as X-11)
6. Built-in muting circuit to deliver output signal when MUTE
TERMINAL is grounded. (available for modules having 30's in
its model number such as H-31)
7. Built-in signal activated muting function (L-41 )
8. Presettable gain control (except for B-01 , B-11 , L-01 and L-11)
9. Microphone modules furnished with tone controls (H-01 , H-02,
H-21, H-22, H-31, H-32 and H-03)
(INPUT CONNECTIONS, T-01 OUTPUT CONNECTION)
Plug-in Modules and Accessories
—7 —

•FORNTPANELCONTROLSANDFEATURES
Moduleswithbuilt-incontrolsareprovidedinthefollowingfive
types.
GAINCONTROL
SENSITIVITY
CONTROL(L-41S)
NOMINALPOSITION
MARK
Thisadjustsgain.Turnclockwise(CW)
toincreaseandcounterclockwise(CCW)
toreducegain.
Setthegainaslowas possible,thereby,
noisecanbereduced,andthemaximum
permissibleinputlevelisraised.
Thisadjustssensitivityformutingother
moduleshavingMUTEfunction.Turn
CWtoraiseandCCWtolowersensitivity.
Settingpositionshoulddependonthe
equipmentconnectedwithL-41S.
Theleftfigureshowsnominal
settingofcontrols.
LOW-CUTFILTER
CONTROL
330Hz,6dB/oct
(max.attenuation)
MUTEDELAY
CONTROL(I-01S)
HIGH-CUTFILTER
CONTROL
4.2kHz,6dB/oct
(max.attenuation)
Thisprovidesflatcharacteristicsatfull
CWpositionandattenuationinlow
frequencybyturningCCW.Adjustitto
obtainpropertonequality.Withlow-cut,
tonebecomesclear.
ThisadjustsMUTEdelaytimewhichis
thedurationfromsignalinputtoits
output.TurnCWtoshortenandCCW
tolengthenthetime.
Thisprovidesflatcharacteristicsatfull
CWpositionandattenuationinhigh
frequencybyturningCCW.Adjustitto
obtainpropertonequality.Withhigh-
cut,tonebecomessoft.
—9 —
*0dBv=1 volt=+2 dBm.* Specificationsaresubjecttochangewithoutnotice.
•SPECIFICATIONSINCOMMON
Loadimpedance: 10k-ohms
Mounting: Card-edgeconnector
Dimensionsinmm(inches): 78(3.07)x35(1.38)x88(3.46)
(H)x (W)x (D)
TOANEW900SERIES
—8 —
Plug-inModules

Block Diagrams (Plug-in Modules)
— 10 —

•
E-11, X-11, L-11, B-11 Series, H-31 and H-32 (with mute)
Connections
(M-900A, A-903A, A-906A, A-912A)
Operation
When the switch is closed,,
a. the signal fed to E-11, X-11, L-11 and B-11 are attenuated by
approx. 60dB. Accordingly a microphone can have a priority at a
time of announcement.
b. the signal fed to H-31 and H-32 are delivered to the amplifier.
(While the switch is opened,the signals areattenuated.)
•
L-41 (with signal activated muting facilities)
When this module accepts the input signal, the mute terminal is
grounded automatically without connection of the remote switch
to the MUTE TERMINAL. It causes the other modules with mute
function, like X-11, to be muted.
Accordingly thesignal fed to the L-41 can have a priority.
•H-21, H-22 and X-21 (Remote volume control facilities)
Operation
Preset the gain control of module and the input volume control 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 output level 1 volt, is used for
transmitting mixing signals of amplifiers to external equipment and
as a REC out.
It is provided with a presettable gain control.
T-01 Series should be used exclusively for TOA 900 series, A-903A,
A-906A, A-912A and M-900A. Use it only in Input Port #5 or #6 of
the above models. It will not operate when connected into other
PORTS.
Approx. 5 seconds after power has been supplied to these modules,
the output signal is transmitted.
•S-01 (1,000Hz SINE WAVE)
It is operated by closing the remote
switch.
Each signal is generated by closing cor-
responding remoteswitch.
•S-03 (ONE-TONE CHIME AND CONTINUOUS ONE-TONE
CHIME)
CONNECTIONS
By closing the remote switch, chime
sounds once.
By closing the remote switch, one-tone
chime sounds continuously during the
closure of the switch.
Operation and Connections
(Plug-in
Modules )
— 11 —

• I-01S (BALANCED PAGING INPUT MODULE)
This module is used for connecting TOA intercom Systems (EXES)
for paging. By connecting this module to the exchange in place of
an intercom station, paging is possible. It is provided with a pre-
settable gain control. The I-01S is applicable to the TOA EXES-
1000, EXES-5000 and EX-16 Intercom Systems.
CONNECTIONS
LMU (Line Modem Unit)
This unit is composed of a modulator to receive signals from
stations, a demodulator to send signals to the station and a scanning
circuit.
Summary Specifications of R and 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 TO USE:
Paging is possible from other station by dialing the station number
assigned to this module. To prevent a calling tone from being
sounded through the paging speaker, the module is designed to
override paging output during a period of time that the calling tone
signal is transmitted. The length of time to mute the paging output
is adjustable between zero and three seconds. During paging,
background music (the input signal fed to E-11, X-11, L-11 or B-11
module) is muted.
Volume Control Cover
YA-910
(BLACK)
Optional Accessories
— 12 —

Schemiatic M-900 A