Toa AX-1000A Specifications

TOA ENGINEERED SOUND SYSTEM

AUTOMATIC

AX-1OOOA

DESCRIPTION

The TOA AX-1000A automatic microphone mixer is ideally
suited for applications such as churches, board rooms,
conference rooms or courtrooms, where multiple
microphones are in use.
Conventional mixers require an increase in total level as the
number of input connections increases. The room loop from
speakers to microphones not currently in use causes the
feedback margin to be lowered.
The US. patented Automatic Mixer Apparatus (U.S. Patent
No. 5148491) on The TOA AX-1000A compensates for each
input, thus doing away with unwanted noise and room loops.
The increase in total level is proportional to the number of
inputs, and attenuation takes place regardless of the input
quantity. This makes it possible to maintain maximum
feedback margin without having to rely on a specialist to
operate the system.
The AX-1000A is a modular eight-channel automatic micro­phone mixer incorporating the technology required to gate
on, configured to shut out unnecessary sound, or to gate off
quietly, quickly and automatically.
The NOM (Number of Open Microphones) attenuation
control circuitry automatically adjusts gain level according to
the number of active inputs. This allows the system to
deliver maximum acoustic gain while preventing feedback.
Each of the AX-1000A’s eight input ports can accept any of
TOA’s 900 Series family of Microphone, Line Level,
Auxiliary, Bridging, Input/Output (except T-01) or Sound
Processing Modules. This allows the contractor or specify­ing engineer ultimate flexibility in system design. Ten (10)
AX-1000A’s may be linked together to create a system with a
maximum of eighty (80) active input channels. When units
are in link mode, any mixer in the chain can operate as the

MIXER

master. This is accomplished by utilizing the Master/Slave
switch on the rear panel. In addition to the main output, the
AX-1000A provides direct and logic outputs for each
channel. The Logic Out is an open collector circuit that can
be utilized to trigger external devices.
The direct output can be used as an input for a logging
recorder to provide an account of the proceedings in a
courtroom communication system.
For flexibility and ease of set-up, each channel is provided
with input volume, threshold and off-attenuation controls.
The Threshold Level control adjusts the level at which the
input gates on. The Off-Attenuation control allows attenua­tion of inactive inputs from 0 to -40dB. In addition, it allows
the adjustment necessary to assure smooth turn on without
any missed syllables.
The input remains on when the Off-Attenuation control is set
at 0dB.
To match virtually any type of application, the NOM attenua­tion control permits adjustments between 0dB (functioning
as a standard mixer) and 20logNOM (6dB attenuation for
each additional active input). The center 10logNOM
position (3dB attenuation for each additional input) is the
standard automatic setting.
Other features include Muting, especially attractive in
conference systems where the chairman must override
other delegates, and a Master Remote Volume control
circuit.
The Off-Attenuation, Threshold and NOM-Attenuation
controls are protected by a security cover to prevent
unauthorized or unnecessary adjustments.
The AX-1000A includes the hardware necessary for
mounting in standard 19” equipment cabinets.

Front View

Input Volume Control

Gate-On LED

Master Volume Control

Master/Slave LED

Channel Controls:

Variable Threshold

Variable Off-Attenuation

THR

OFF ATT

NOM ATT

Power Switch
and LED

Each threshold control adjusts its channel’s detector, raising and lowering the
baseline sensitivity to an incoming signal. It determines how easily the input will
gate ‘on’. Threshold is independent of the Off-Attenuation setting.

This control, permitting continuous adjustment of a channel’s Off-Attenuation

(depth), operates from 0dB (full CW) to -40dB (full CCW). In the 0dB position, the
channel acts as a conventional mixer input. At that setting there is no attenuation
of the input whether it is above or below threshold.

Channel
output:

Relation of Threshold
and Off-Attenuation
Controls (simplified):

Channel

System Output Gain:

Adjustable NOM Attenuation

Automatic gain reduction is continuously variable from none to 20logNOMdB.

(NOM=‘Number of Open Mics’.) At the center detent, the attenuation of system
output gain follows the standard formula “10logNOM”. When the control is moved

clockwise, the attenuation is deeper, moving from 10logNOM to 12logNOM,

15logNOM, etc.

Attenuation is at a maximum fully clockwise, following the formula 20logNOM.
With the control set fully counterclockwise there is no system output gain attenua-

tion and the AX-1000A functions as a normal mic/line mixer. Between no attenua-

tion and the detent, output gain is attenuated more and more up to 10logNOM.

2
Active Inputs (NOM)

20logNOM

20logNOM

0 dB Attn.

4

8
Inputs

10 16 20 40

80
Inputs

Rear View

Remote Master

Volume Terminals

Modular Inputs

In a significant advance for automatic
mixing systems, the AX-1000A uses TOA’s
standard 900 Series input modules. Any
combination of Mic and Auxiliary Preamps
can be specified in an installation. If it is
important to allow for future expansion, only
a few of the input ports need be used.
Logic outputs, direct outputs, link in and
out, system mute terminals and remote
master volume control terminals are located
on the rear panel.

Module Direct-Output
Jacks (1/4”)

Logic Output Terminals

Master/
Slave Switch

SLAVE

Main Output Terminal
600 ohms or 150 ohms

System Mute Terminals
(Priority Override)

Channel Mute
DIP Switches

Function
Select

Link In

& Out

System Mute

(Priority Override)

Direct Outputs

Logic Outputs

Link In and Out

A DIP switch determines which channels are muted when the two rear-panel mute
terminals are shorted by a relay or switch closure.
AX-1000A Internal Muting occurs within the mixer, after the signal has left the input
module itself. Thus, any 900 Series input module will be muted when the contacts
are closed. The module does not have to be a 900 Series ‘muting module,.

In fact, by using 900 Series muting modules, two levels of muting are possible.
The first level can be automated. It utilizes the Mute Send and Mute Receive
features of certain 900 Modules. The second level utilizes the

Mute built

into the AX-1000A.

Each channel’s Direct Output provides a signal from the corresponding module.
It has been processed by the preamplifier and other circuitry in the module itself,
including, for example, compression in the case of the U-61 module. However,
the Direct Output signal is unaffected by the action of the AX-1000A’s gating,
muting, or gain-sharing circuits.

Each channel’s Logic Output is an open-collector circuit. The logic outputs may be

connected to relays for automatic initiation of events in an automatic zonal switching
system, triggering video camera controls, etc.

When AX-1000A mixers are run in multiple, one of the mixers operates as the Master
and the rest operate as Slaves. The Master/Slave relationship is determined by the
rear-panel slide switch. The Master is connected to the Slaves using the Link In and
Out connectors. An optional Link cable is available.

Main Output

The Main Output barrier strip can be configured for

by moving the jumpers (provided).

150

ohms or 600 ohms operation

900 Series Plug-In Modules Specifications & Selection Guide

Connector

Specifications

Max. Before Clip

into 10k ohms load

Frequency

Noise Level

as less than 0.5% THD

Response

Equivalent

Signal

Muting

(1kHz)

±1dB

Input Noise

or S/N

Level

Remote Compress.

Power

Control Range

Requirement

Range [Threshold]

[24V DC]

Controls

Weight

[Presettable] (Max.)

9mA
14mA
30mA

XLR-3-13

(F)*

M-01F

1-Low cut
1-High cut
1-Gain

3.88 oz.

2.82 oz.

3.17 oz.

-

-

27mA

3.88 oz.

M-51 F

33mA

1-Low cut
1-Sensitivity
1-Gain

1-Low cut
1-High cut
1-Threshold

1-Low cut
1-High cut
1-Gain

3.88 oz.

M-61 F

9mA

2.12 oz.

-

9mA

1-Gain

1.76 oz.

-

4mA
14mA
27mA
27mA
30mA

2.65 oz.

U-01F

1-Gain

1.76 oz.

1.76 oz.

2.12 oz.

1.94 oz.

-

1-Mute level
1-Gain

-

-

1-Gain

-

38mA

1-input gain
1-Output gain

3.70 oz.

-

- -

3.17 oz.

3.35 oz.

3.17 oz.

3.35 oz.

B-01 F

60dB

5mA

- -

-

-

L-01 F

5mA

-

8.5mA 1-Sensitivity

3.35 oz.

15mA

1-Mute
1-Gain

3.53 oz.

35mA

1-Gain

3.53 oz.

7mA
11mA

1-Output

1.94 oz.

2.12 oz.

16mA 2.47 oz.

5P screw

Terminal (S)

-

-

M-21S

-

-

-

-

-

-

-

-

U-21s

-

T-02S

-

-

-

-

-

l-01S

-

-

-

-

Applications

Module

11mA

Input Sensitivity
for Rated Output
(- 20dBv/100mV)

Gain

1-Definition
1-Lo Contour

Source

Impedance

Balanced
200 ohms

Unbalanced
50k ohms

Unbalanced
50k ohms

Unbalanced
220k ohms

Unbalanced
10k ohms

Unbalanced
220k ohms

Output

Balanced

600 ohms

Balanced
10k ohms

Balanced

Types

XLR-3-14 Phone Jack RCA Phono

(m)* (P)*

Jack (R)*

M-01M M-01P

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

M-03P

-

U-01P

-

-

-

-

-

B-01P

-

L-01P

-

-

-

-

-

-

-

-

-

-

-

-

R-01 R

U-01R
U-11R

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

60dB

6.3V (+ 16dBv)

Nominal - 60dBv (1.0mV)

- 126dBm,

Adjustable - 72 - - 52dBv

25 - 20,000Hz

200 ohms

(0.25 - 25mV)

terminated

-

6.3V ( + 16dBv)

20 - 20,000Hz

SIN 70dB

-

6.3V ( + 16dBv)

RIAA
Equalized

SIN 70dB

-

-

6.3V ( + 16dBv)

20 - 20,000Hz

S/N 90dB

60dB
Adjustable

0 - 60dB

-

-

20 - 20,000Hz

S/N 90dB

20 - 20,000Hz

S/N 90dB

-

6.3V ( + 16dBv)

-

6.3V ( + 16dBv)

4.7V (+ 13.4dBv)
into 600 ohms load

30 - 20,000Hz

S/N 80dB

-

20 - 20,000Hz

-

-

-

20 - 20,000Hz

-

60dB

Balanced

Nominal 3.2V Nominal - 30dB

600 ohms

Adjustable 3.2 - 10V Adjustable - 30 - - 40dB

-

500 - 20,000Hz

-

Low-cut 250Hz

6.3V ( + 16dBv)

4.7V (+ 13.4dBv)
into 600 ohms load

30 - 20,000Hz

S/N 80dB

- -

0.5V (- 6dBv) 0.5% THD

- -

1V peak to peak

-

-

1V peak to peak

S/N 80dB

20 - 20,000Hz

S/N 80dB

3P screw

Terminal (S)

M-01S
M-11S

-

M-51s

M-61S

-

-

U-01S
U-11S
U-12S

-

U-61S

-

B-01S

B-11S
L-01S
L-11S

L-41S

-

T-01S

S-01S
S-02S

S-03S

-

M-01 series

Mute or Mute

M-11

Remote Volume Control facilities

M-21

Voice Gate

M-51 series

Compressor

M-61 series

Low

Z

Gain Control
(except M-61)

Low-cut Filter
High-cut Filter

(except for M-51)
Phantom Power

0-

-60dB

-

Microphone
Preamplifier

Mag. Phono
Preamplifier

Auxiliary
Preamplifier

--

Auxiliary
Input Line
output

­20dB

Threshold
adjustable 0.5 - 5mV

Nominal - 50dBv (3.2mV)
Adjustable - 62 - - 42dBv
(0.8 - 8.0mV)

Nominal - 54dBv (2.0mV)
Adjustable - 54 - -46dBv
(2.0 - 5.0mV)

High Z, Gain
Control, Low-cut
and High-cut Filters

-

M-03

Gain Control

-

R-01

-

U-01 series

Mute

U-11 series

Variable Mute

U-12

4 oz.

2-RCA Phono (Input/Output)

Nominal - 20dBv (100mV)
Adjustable - 20 - + 10dBv

Nominal 0dB

(100 - 3,200mV)

Adjustable 0 - - 30dB

-

Gain Control

Remote Volume or Remote
Master Volume Control facilities

U-21

0-

-60dB

-

20dB
Threshold 1.0V

Rated output Nominal 0dB
0dBv (1.0V)

Adjustable 0 - - 30dB

Compressor

U-61

Nominal - 20dBv (100mV)
Adjustable - 20 - 0dBv

Nominal 0dB

(100 - 1,000mV)

Adjustable 0 - - 20dB

AUX

Output Gain Control
Input Gain Control

T-02

LINE
OUT

Nominal 20dB

Rated output 0dBv (1.0V)

(1.0 - 158mV output)

B-01 series

Bridging
Transformer

-

- 18dBv (125mV)

- 1dB

Mute

Mute

-

B-11 series
L-01 series
L-11

-18dBv (125mV)

- 2dB

Line
Matching
Transformer

600 ohms

Sensitivity Control

Signal Activated Mute

L-41

Gain Control
Mute Delay Control

-

l-01

Paging Input

-

Nominal 20dB
(1.0V output)
Adjustable 20 - 4dB
(1.0V - 158mV)

-

T-01

Output
Balanced

600 ohms

1 kHz Sine Wave S-01

-

Buzzer/Yelp

S-02

-

Line Output

Gain Control

Tone Signal
Generator

Gain Control

One Tone Chime/
Continuous Chime

S-03

-

BBE Sound
Processing
Module

No Connection to
Mix Buss

Definition, Low
Contour, On-Off

lncreased Intelligibility, Paging, F-01R

47k ohms

N/A

APPEARANCE AND DIMENSIONAL DIAGRAM

Module

Application Note

l-01S

Designed for interface with TOA EXES intercom systems.

L-41S

Must occupy port No. 2 when used in conjunction with A-901A.

M Series

Phantom power is defeatable by cutting jumper J-l on the module.

T-O1S

Will not function in the A-901A. Functions only in ports No.s 5 and 6 when
used with the following models: M-900A, A-903A, A-906A, A-912A, W-906A
and W-912A.

U-61S

Can
and

when used between the pre-amplifierfunction as a master compressor

power amplifier sections.

With W-906A and W-912A in-wall amplifiers use screw terminal modules only.

SPECIFICATIONS

Frequency Response
Total Harmonic Distortion Less than 0.1%, at 1 kHz signal input
Signal to Noise Ratio

Inputs

Input Sensitivity and

Impedance

outputs

Controls

Number of Max. Stacking

Max. Attenuation Level

-Attenuation System 10logNOM (Number of Open Mics) typical

Line Voltage

Fuse

Dimensions

Weight

*Specifications are subject to change without notice.

20Hz to 20kHz ± 1 dB

Better than 90dB, with all Vol. Min.
Better than 77dB, with Band Pass 20Hz to 20kHz,

Input Vol. Min., Master Vol. Max.

8 x Input port for TOA 900 Series modules
1 x Link In (stacking)

Input ports: 100mV, 10k ohms
Link In: 100mV, 10k ohms Audio Signal

1 x Main output: 600 ohms/150 ohms, balanced,

transformer isolated

8 x Direct outputs: 680 ohms; Nominal -20dBV

(100mV); Maximum +16dBV (6.3V)

1 x Link out: 100mV, 1k ohms

8 x Logic out: isolated open collector (30mA,

24V DC max.)

8 x Input volume

1 x Master volume

8 x Threshold controls

1 x NOM Attenuation control

8 x Off-Attenuation controls

1 x Master/Slave switch
1 x set of 8 Channel Mute DIP switches
1 x INT/EXT Mute Function Select switch

10

units (80 channels)

20dB per AX-1000A

(Continuous adjustable from 0dB to

20logNOMdB)
AC mains
05A, 250V, fast blow

fuses not user accessible: see service

manual

16.5 (W) x 6.0 (H) x 12.9 (D) inches

420 (W) x 151.3 (H) x 327.5 (D) mm

19” rack-mountable, 3 EIA rack units

15.5lbs. (7.0kg)

BLOCK DIAGRAM

Architect’s and Engineer’s Specifications

The automatic microphone mixer shall have eight input ports and shall
be capable of accepting a full complement of TOA 900 Series Micro-

phone, Line Level, Auxiliary, Bridging, Input/Output (except T-01) and
Sound Processing Input Modules. The automatic mixer shall incorporate
a continuously variable, adjustable NOM-Attenuation control (with a

range from 0logNOM to 20logNOM with a center detent at 10logNOM)
to allow precise adjustment of automatic mixing circuitry to the acousti­cal environment of the facility in which the device shall be utilized.

For flexibility and ease of set-up, each channel shall be provided with

Input Volume, Threshold Level and Off-Attenuation controls. The Threshold

Level control shall adjust the level at which the input gates on. The Off­Attenuation control shall be continuously variable and shall allow attenuation
of an inactive input from 0 to -40dB. The Off-Attenuation setting shall

not affect the channel gating, ensuring smooth turn-on without any

missed syllables. The Input Volume, Threshold Level, Off-Attenuation,
and NOM-Attenuation controls shall be front-panel mounted for ease of

set-up. A security cover shall be provided to protect the Off-Attenuation,
Threshold and NOM-Attenuation controls from unauthorized use.

Each input channel shall incorporate a front panel LED to visually

indicate the gating function. A link Input/Output shall be provided
allowing up to ten (10) devices together to create a system with a

maximum of eighty (80) input channels.
A rear panel Master/Slave switch shall be provided to allow any unit to
function as a Master or Slave unit when multiple units are incorporated

into a sound reinforcement system. A front panel LED shall visually

indicate the position of the Master/Slave switch.
The automatic mixer shall incorporate logic outputs for each channel.
The Logic Out shall be an open collector circuit that can be utilized to
trigger external devices. The automatic mixer shall provide direct

outputs for each channel, providing a buffered audio signal from the

corresponding input module.
The direct output shall only be affected by the circuitry within the input

module; it shall not be affected by the mixer’s gating, muting or gain-

sharing circuits. The direct outputs shall be capable of being passively

mixed. Dip switch selectable muting shall be provided to allow a

“chairman override” function for any combination of channels. Muting

shall be accomplished by shorting the rear panel mute terminals via a

switch closure or relay contact.

By utilizing TOA 900 Series Muting Input Modules it shall be possible to

provide two levels of muting. Rear panel Remote Master Volume

terminals shall be provided, the maximum gain of which shall be limited

by the front panel master volume control setting. Control shall be via a

10k linear potentiometer.
The unit shall measure 19.0”(W) x 5.22”(H) x 11.8”(D) (483mm x 133mm
x 300mm) with rack-mount hardware attached, shall have an aluminum
anodized front panel and shall weight 15.5lbs (7.0kg). With standard
rack mount hardware the unit shall require 3 EIA Rack Units. The
modular eight (8) channel automatic mixer shall be a TOA Model
AX-1000A.

TOA Corporation

Printed in Japan (407) 833-62-087-1A