TOA a-901a Guide De Spécification

Specifications

Frequency Response

at 1 /10 rated output (490-ohm load)

Type

3-channel mixer power amplifier

Output Power

10 watts RMS

Power Bandwidth

50—20,000 Hz, 2% THD

Frequency Response

2 0 — 2 0 , 0 0 0   H z ,  ± 1 dB

Total Harmonic Distortion

0.1% at 1 kHz, rated output

lnputs

Two input ports: Each port accepts any input

module except the T-01,  which cannot be used.
One program input

Input Sensitivity/Impedance

Input ports #1 & #2: 100 mV/10k ohms
Program input: 100 mV/50k ohms

Source Impedance

200 ohms with M-01/M-11/M-21/M-51/M-61 module
(balanced Lo Z microphone preamplifier)
50k ohms with M-03P module
(unbalanced Hi Z microphone preamplifier),
R-01R module (mag. phono preamplifier)
220k ohms with U-01/U-11/U-12/U-21/U-61 module
(auxiliary preamplifier)

10k ohms with B-01 module

(bridging transformer)
600 ohms with L-01 module
(line matching transformer),

1-01 (paging input)

Outputs

4 and 8 ohms, 25 and 70 volts, balanced

(Transformer-isolated)

Output Regulation (1 kHz)

Less than 2.0 dB, no load to full load

Signal-to-Noise Ratio
(Band Pass: 20-20,000 Hz)

All gain controls max: 82dB

With Tone Controls Centered

Tone Controls

Bass: 

±10 dB at 100 Hz; Treble: ±10 dB at 10 kHz

Controls affect only input port #1 and program input

Controls

2 input gain controls 1 program gain control

1 program gain limit control 1 bass tone control
1 treble tone control 1 power ON/OFF switch

Indicators

1 power LED 1 max. output LED

Protection Circuitry

Built-in with 1 AC fuse Output circuitry protection when
heatsink temperature overheats

Connectors

Inputs #1 & #2: Card-edge connectors

Program input: RCA phono jack
Output: Screw-terminal strip
Mute: 2-pin socket

Power Consumption

Temperature Range

Dimensions

Weight

(without input modules)

Color

Standard Accessory

Other Features

Optional Accessories

AC power cord/plug: SJT, 3-prong type

AC 120 volts, 60 Hz, 30 watts

-10°C to +60°C (12°F to 140°F)

3.98"(H)X9.84"(W)X9.65"(D) (101X250x245mm)

Rack-mounting space size:"2U" (3.46")

8.6 Ibs. (3.9 kg)

Silver

1 muting terminal plug

Program input and input port #1 muted
simultaneously

Plug-in modules
(see specifications for individual modules),
rack mounting bracket model MB-920

*Specifications are subject to change without notice

* NOTE 1: THE T-01S MODULE WILL NOT FUNCTION IN THE A-901A

MIXER POWER AMPLIFIER.

* NOTE 2: THE L-41S MUST OCCUPY PORT NUMBER TWO WHEN

UTILIZED IN THE A-901A.

Power Output vs Frequency
at 2% THD (490-ohm load)

Architect’s and Engineer’s Specifications

The mixer power amplifier shall have two input ports and one program

input. It shall be capable of operation from a 120V, 50/60Hz line. Input
ports shall be usable with microphone, phono pickup or high-level devices,

and program input shall be usable with high-level devices. The amplifier
shall meet the following performance criteria. Power output shall be 10W at
less than 2% THD from 50 to 20,000Hz. Frequency response shall be

± 1dB from 20 to 20,000Hz. Source impedance shall be 200/50k ohms

with a microphone preamplifier, 50k ohms with a mag. phono
preamplifier, 220k ohms with an auxiliary preamplifier, 10k ohms with a
bridging transformer, 600 ohms with a line matching transformer and 600
ohms with a paging input. Load impedance shall be 4, 8, 62.5 (25-volt line)

or 490 ohms (70-volt line). Load voltage shall be 6.3, 8.9, 25 or 70 volts.

Equivalent input noise shall be - 126dBm with a Lo Z microphone
preamplifier. Output noise shall be 90dB below rated output when all gain

controls are off.
The TOA plug-in accessory modules designed for use with the A-901A

mixer power amplifier shall utilize the latest in surface mount component

technology and include the following modules: the M Series microphone

preamplifiers with muting, remote volume control, voice gate and
compressor options, the U Series auxiliary preamplifiers available with
muting, remote volume control and compressor options. The R-01R
magnetic phono preamplifier. The B Series bridging transformers,
available with muting option, the L Series line matching transformers,

available with muting option, the S Series signal generator modules and

the 1-01S Exes interface paging module. The T-02S module featuring
auxiliary input and balanced line output shall also be available for music-
on-hold.
The mixer power amplifier shall be rack mounted using the TOA MB-920

rack mounting bracket. The amplifier’s dimensions shall be 3.98"(H) x

9.84"(W) x 9.65"(D) (101 x 250 x 245mm) and its weight shall be 8.6 Ibs.
(3.9kg).
The mixer power amplifier shall be TOA model A-901A.

TOA Corporation

PRINTED IN U.S.A