Advertisement
TOA NEW 900 SERIES
MIXER POWER AMPLIFIER
Features
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
Toa Electric Co., Ltd.
KOBE, JAPAN
Operating Instruction Manual
General Description
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.
A-903A
A-906A
A-912A
Advertisement
Table of Contents
Subscribe to Our Youtube Channel
Related Manuals for Toa A-903A
Summary of Contents for Toa A-903A
-
Page 1: General Description
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. -
Page 2: Front Panel Controls And Features
TOA NEW 900 SERIES Front Panel Controls and Features A-903A Item Name POWER ON-OFF SWITCH METER INPUT VOLUME CONTROLS BASS CONTROL TREBLE CONTROL TONE SWITCH MASTER VOLUME CONTROL Block Diagram A-906A, A-912A Function/Description Applies line power. Two-position push button switch for on-off modes. -
Page 3: Rear Panel Controls And Features
Rear Panel Controls and Features A-903A Item Name AC POWER SUPPLY CORD AC OUTLET (Unswitched) AC FUSE OUTPUT FUSE OUTPUT TERMINALS MODULE INPUT PORTS LOW-CUT SWITCH LINK SWITCH AUX OUT POWER AMP IN PREAMP OUT BRIDGING INPUT/ OUTPUT MUTE TERMINAL... -
Page 4: Input Connections
TOA NEW 900 SERIES Input Connections This unit 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. -
Page 5: Installation
Output Connections P-906A, P-912A The speaker outputs of the amplifier are 4 , 8 Connect speakers to one of these outputs. Class 2 wiring may be used. Since these outputs consist of 8 , 25V and 70V via the output transformer (matching transformer) and direct output of 4 connecting method differs in each case. -
Page 6: Operation
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. — 5 — Rack Mounting... -
Page 7: Specifications
: 100 mV/10k ohms Bridging Input/Output: 100 mV/3.3k ohms 1,000 mV into 600 ohms/1,000 mV, 10k ohms Main (T) : 8 ohms, 25 & 70 volts, balanced Main (D): 4 ohms, unbalanced : 10k ohms, 1,000 mV (T) Less than 1.0 dB, no load to full load Master volume min. - Page 8 Plug-in Modules and Accessories (OPTION) The TOA PLUG-IN MODULES are suitable for TOA 900 S E R I E S MIXER POWER AMPLIFIERS A-901A, A-903A, A-906A, and A-912A M I X E R P R E A M P L I F I E R M-900A, and POWER AMPLI- F I E R S P-906A, P-912A and P-924.
- Page 9 TOA NEW 900 SERIES Plug-in Modules Module Applications Types Input Sensitivity Source Impedance for Rated Output (100 mV) Low Z MIC H-01 series with Low & High filters Low Z MIC with Low & High filters H-21 and remote volume...
- Page 10 TOA NEW 900 SERIES Block Diagrams (Plug-in Modules) H-01 Series H-21S H-31S H-02 Series H-22S H-32S H-03 Series E-01 Series E-11 Series X-01 Series X-11 Series X-21S B-01 Series B-11 Series L-01 Series L-11S L-41S T-01 Series S-01S S-02S S-03S I-01S —...
- Page 11 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.
-
Page 12: Operational Accessories
TOA NEW 900 SERIES I-01S (BALANCED PAGING INPUT MODULE) This module is used for connecting TOA intercom Systems ( E X E S ) 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. - Page 13 — 13 —...
- Page 14 TOA NEW 900 SERIES — 14 —...
Need help?
Do you have a question about the A-903A and is the answer not in the manual?
Questions and answers