Toa A-3606D User manual

OPERATING INSTRUCTIONS
MIXER AMPLIFIER
Thank you for purchasing TOA’s Mixer amplier.
Please carefully follow the instructions in this manual to ensure long, trouble-free use of your equipment.
A-3606D, A-3612D, A-3624D, A-3648D
The gure represents the A-3648D.
About Firmware Upgrade
The latest rmware is available on the TOA DATA Library (https://www.toa-products.com/international/).
Perform a search for the product number "A-3606D, A-3612D, A-3624D, or A-3648D" and download
the latest rmware.

2
TABLE OF CONTENTS
1. SAFETY PRECAUTIONS ............................................................................. 3
2. GENERAL DESCRIPTION .......................................................................... 5
3. FEATURES ............................................................................................................ 5
4. HANDLING PRECAUTIONS ...................................................................... 5
5. INSTALLATION PRECAUTIONS ............................................................. 6
6. THE DUCKER FUNCTION AND
THE PRIORITY BROADCAST FUNCTION ..................................... 6
7. NOMENCLATURE AND FUNCTIONS ................................................. 7
Front ............................................................................................................................. 7
Rear ............................................................................................................................. 8
8. CONNECTIONS ............................................................................................... 12
8.1. Speaker Connection ........................................................................................... 12
8.2. Input Terminal Connections and Settings ......................................................... 13
8.3. Connecting to the Remote Master Volume Control Terminal ............................. 15
8.4. Connecting to the Power Remote Control Output Terminal ............................... 15
8.5. Connecting to the Emergency Control Output Terminal ................................... 16
8.6. Connecting to the Zone Control IN/OUT Terminal ............................................. 16
8.7. Connecting to the Control Input Terminal ........................................................... 17
8.8. Connecting the External Equipment between the Line Output and
the Power Amplifier ............................................................................................ 17
8.9. Removable Terminal Plug Connection ............................................................... 18
9. SETTINGS ........................................................................................................... 19
9.1. Chime Tone Setting ............................................................................................ 19
9.2. Line Output Interlock Switch Setting .................................................................. 19
10. DUCKER DEPTH ADJUSTMENT ...................................................... 19
11. VOLUME ADJUSTMENT ......................................................................... 20
12. SPEAKER ZONE SELECTION ............................................................ 20
13. INSTALLING TO AN EQUIPMENT RACK .................................... 21
14. CONTROL SETTINGS ............................................................................. 21
15. PRIORITY BROADCAST FUNCTION .............................................. 22
15.1. Priority Broadcast ............................................................................................ 22
15.2. Priority Broadcast Mode ................................................................................... 22
15.3. Emergency Broadcast ...................................................................................... 24
15.4. Normal Broadcast ............................................................................................. 24
15.5. Relationship between Priority Broadcast
by Control Input/Emergency Broadcast and Power On/Off ............................. 24
15.6. Factory Default Settings ................................................................................... 25
15.7. Setting Examples and Operation Images ......................................................... 26
16. SETTINGS ON THE BROWSER ......................................................... 29
17. BLOCK DIAGRAM ....................................................................................... 30
18. SPECIFICATIONS ........................................................................................ 31
Accessories .............................................................................................................. 32
Optional products ...................................................................................................... 32

3
When Installing the Unit
• Do not expose the unit to rain or an environment
where it may be splashed by water or other liquids,
as doing so may result in re or electric shock.
• Use the unit only with the voltage specied on
the unit. Using a voltage higher than that which is
specied may result in re or electric shock.
• Do not cut, kink, otherwise damage nor modify
the power supply cord. In addition, avoid using the
power cord in close proximity to heaters, and never
place heavy objects -- including the unit itself -- on
the power cord, as doing so may result in re or
electric shock.
• Be sure to ground to the safety ground (earth)
terminal to avoid electric shock. Never ground to a
gas pipe as a catastrophic disaster may result.
• Avoid installing or mounting the unit in unstable
locations, such as on a rickety table or a slanted
surface. Doing so may result in the unit falling down,
causing personal injury and/or property damage.
• Since the unit is designed for indoor use, do not
install it outdoors. If installed outdoors, the aging of
parts causes the unit to fall off, resulting in personal
injury. Also, when it gets wet with rain, there is a
danger of electric shock.
• The terminals marked with the symbol are
hazardous live.
The external wiring to these terminals requires
installation by an instructed person.
When the Unit is in Use
• Should the following irregularity be found during
use, immediately switch off the power, disconnect
the power supply plug from the AC outlet and
contact your nearest TOA dealer. Make no further
attempt to operate the unit in this condition as this
may cause re or electric shock.
· If you detect smoke or a strange smell coming
from the unit.
· If water or any metallic object gets into the unit
· If the unit falls, or the unit case breaks
· If the power supply cord is damaged (exposure of
the core, disconnection, etc.)
· If it is malfunctioning (no tone sounds.)
• To prevent a fire or electric shock, never open nor
remove the unit case as there are high voltage
components inside the unit. Refer all servicing to
your nearest TOA dealer.
• Do not place cups, bowls, or other containers of
liquid or metallic objects on top of the unit. If they
accidentally spill into the unit, this may cause a re
or electric shock.
• Do not insert nor drop metallic objects or ammable
materials in the ventilation slots of the unit’s cover,
as this may result in re or electric shock.
• Do not touch a power supply plug during thunder
and lightning, as this may result in electric shock.
Indicates a potentially hazardous situation which,
if mishandled, could result in moderate or minor
personal injury, and/or property damage.
CAUTION
When Installing the Unit
• Never plug in nor remove the power supply plug with
wet hands, as doing so may cause electric shock.
• When unplugging the power supply cord, be sure to
grasp the power supply plug; never pull on the cord
itself. Operating the unit with a damaged power
supply cord may cause a re or electric shock.
Indicates a potentially hazardous situation which,
if mishandled, could result in death or serious
personal injury.
WARNING
1. SAFETY PRECAUTIONS
• Before installation or use, be sure to carefully read all the instructions in this section for correct and safe
operation.
• Be sure to follow all the precautionary instructions in this section, which contain important warnings and/or
cautions regarding safety.
• After reading, keep this manual handy for future reference.
Safety Symbol and Message Conventions
Safety symbols and messages described below are used in this manual to prevent bodily injury and property
damage which could result from mishandling. Before operating your product, read this manual rst and
understand the safety symbols and messages so you are thoroughly aware of the potential safety hazards.

4
Warning: Operation of this equipment in a residential environment could cause radio interference.
• When moving the unit, be sure to remove its power
supply cord from the wall outlet. Moving the unit
with the power cord connected to the outlet may
cause damage to the power cord, resulting in re or
electric shock. When removing the power cord, be
sure to hold its plug to pull.
• Do not block the ventilation slots in the unit’s cover.
Doing so may cause heat to build up inside the
unit and result in re. Also, periodically clean the
ventilation slots of dust.
• Avoid installing the unit in humid or dusty locations,
in locations exposed to the direct sunlight, near the
heaters, or in locations generating sooty smoke
or steam as doing otherwise may result in re or
electric shock.
• To avoid electric shocks, be sure to switch off the
unit’s power when connecting speakers.
• Be sure to follow the instructions below when rack-
mounting the unit. Failure to do so may cause a re
or personal injury.
· Install the equipment rack on a stable, hard oor.
Fix it with anchor bolts or take other arrangements
to prevent it from falling down.
· When connecting the unit’s power cord to an AC
outlet, use the AC outlet with current capacity
allowable to the unit.
· Rack-mounting screws are not supplied with the
optional MB-25B Rack mounting bracket. Prepare
them that are appropriate for the equipment rack.
When the Unit is in Use
• Do not place heavy objects on the unit as this may
cause it to fall or break which may result in personal
injury and/or property damage. In addition, the
object itself may fall off and cause injury and/or
damage.
• Make sure that the volume control is set to minimum
position before power is switched on. Loud noise
produced at high volume when power is switched
on can impair hearing.
• Do not operate the unit for an extended period of
time with the sound distorting. Doing so may cause
the connected speakers to heat, resulting in a re.
• Contact your TOA dealer as to the cleaning. If dust is
allowed to accumulate in the unit over a long period
of time, a re or damage to the unit may result.
• If dust accumulates on the power supply plug or
in the wall AC outlet, a re may result. Clean it
periodically. In addition, insert the plug in the wall
outlet securely.
• Switch off the power, and unplug the power supply
plug from the AC outlet for safety purposes when
cleaning or leaving the unit unused for 10 days or
more. Doing otherwise may cause a re or electric
shock.
• The socket-outlet shall be installed near the equipment and the plug (disconnecting device) shall be
easily accessible.
• The apparatus shall be connected to a mains socket outlet with a protective earthing connection.

5
2. GENERAL DESCRIPTION
TOA’s A-3600D Series is a PA amplier equipped with 4 microphone inputs and 3 auxiliary inputs, and 2-channel
zone selector.
In addition to each individual input volume control function, it is equipped with the following functions.
• Priority broadcast function
• Chime function
• Remote conrmation function
• Digital signal processing function
Also, the PFC circuit is provided inside.
The A-3600D Series mixer amplier is ideal for paging announcement and BGM applications in schools, ofces,
and super markets.
3. FEATURES
• 4 kinds of power amplifier outputs: 60 W (A-3606D), 120 W (A-3612D), 240 W (A-3624D), and 480 W (A-3648D)
• Lightweight owing to the built-in digital power amplifier unit
• Emergency broadcast and priority broadcast activated by way of the control input (contact)
• Voice detection function that allows the priority broadcast to be activated by voice
• Priority setting function
• Remote conrmation function that allows you to conrm the unit’s status through the web browser using a PC
• Switchable speaker output
A-3606D: 8 to 16 Ω or 100 V line
A-3612D, A-3624D, A-3648D: 4 to 16 Ω or 100 V line
• Zone selection buttons for making broadcasts to 2 zones
• Electronically-balanced 4 microphone inputs (MIC 1 to MIC 4) with input setting switches
• Fine sound adjustment possible by connecting a signal processor like an equalizer between the line output
and the power amplifier input
• Bass and treble tone control knobs
• Output level meter
• Master volume control knob to simultaneously adjust all input levels
• Remotely controllable master volume
• Built-in chime unit (1-note tone, 2-note tone, and ascending 4-note tone)
• Equipped with the following signal processing functions:
FBS (Feedback suppression function), Equalizer (3 points), Gate, Software volume, Limiter, and Ducker
4. HANDLING PRECAUTIONS
• In this system, settings and control of the unit are performed on a PC via LAN (Local area network). It is not
possible to perform them via the Internet.
• Some operations differ depending on this unit’s power ON/OFF state. The table below shows the relationship
between the power ON/OFF state and the corresponding operation.
Power state LED lighting state Normal broadcast Priority broadcast/
Emergency broadcast
Web
access
CPU
RUN
From
Speaker
output
From
Recording
output
Not energized Unlit Unlit Disabled Disabled Disabled Disabled
Energized
(Power turned OFF)
Unlit Lit Disabled Disabled Occasionally possible
( Power is temporarily
turned ON.)
Enabled
Energized
(Power turned ON)
Lit Lit Enabled Enabled Enabled Enabled

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5. INSTALLATION PRECAUTIONS
• The supplied power supply cord is designed for exclusive use with the unit. Never use it with other equipment.
• Install the unit in a well-ventilated environment so that temperature inside the unit will not rise.
• When installing the unit on the desk, keep the unit over 10 cm away from objects that may obstruct air ow as
shown below.
• When installing the unit in an equipment rack, mount perforated panels. See "INSTALLING TO AN EQUIPMENT
RACK" on p. 21.
Over 10 cm
Over 10 cmOver 10 cm
A-3600D Series
6. THE DUCKER FUNCTION AND THE PRIORITY BROADCAST FUNCTION
This unit is provided with Ducker function and Priority broadcast function that decrease the output level of other
broadcasts while a specic broadcast is being made.
A Ducker function refers to the function to place a priority order between the audio signal groups divided into 2
groups. Use this function to make a simple usage such as to decrease the BGM level when making microphone
announcement while the BGM broadcast is in progress.
For the details of the Ducker function, See "DUCKER DEPTH ADJUSTMENT" on p. 19.
A Priority broadcast function is the function to assign one of 6 priority levels to each broadcast content. Use this
function to make a complicated usage compared with the Ducker function such as to select the audio signal to
mute.
For the details of the Priority broadcast function, See "PRIORITY BROADCAST FUNCTION" on p. 22.

7
1. Power switch
Press this switch to turn on the power. To turn off
the power, press this switch again.
Note
Operation of the power switch is disabled while the
priority broadcast or the emergency broadcast is in
progress.
( See "PRIORITY BROADCAST FUNCTION" on p. 22.)
2. Power indicator (Green)
Lights when the power is switched on and goes off
when it is switched off.
3. Reset key
Press this key for 1 second or more to reset the
unit.
Use a ne-tipped object to press in this switch.
Note
Perform the following steps before pressing the Reset
key.
• Turn all volume knobs fully counterclockwise to
minimize the volume value.
• Conrm that both the Priority broadcast indicator
(12) and the Emergency broadcast indicator (11) are
unlit.
• Press the Power switch (1) to turn it OFF.
4. LED level meter (Green x 3, Orange x 1, Red x 1)
Displays the output level.
Adjust each volume control knob for an appropriate
output sound so that the red indicator does not
light.
Operating the unit while the red indicator remains
lit causes the sound quality to degrade.
5. Zone selection buttons
Select the broadcast zones. Pressing the Zone 1
selection button causes the Zone 1 to be selected,
outputting the signals from the zone 1 speaker
output terminal (31) on the rear panel.
In the same manner, pressing the Zone 2 selection
button causes the Zone 2 to be selected, outputting
the signals from the zone 2 speaker output terminal
on the rear panel.
Note
These buttons are effective only when the output
impedance setting switch (32) is set to 100 V line
(high impedance).
6. Zone indicator (Green)
The indicator of the zone selected by the Zone
selection button (5) lights.
Note
These indicators work only when the output
impedance setting switch (32) is set to 100 V line
(high impedance).
7. Error indicator (Red)
Lights when the unit’s internal abnormality has
occurred.
8. Overcurrent protection indicator (Red)
Lights while the overcurrent protection circuit is
operating if overcurrent ows through the speaker
output.
9. Thermal protection indicator (Red)
Lights while the internal protection circuit is
operating.
1
2
34
14 15 16 17
56
7
11
8
9
10
12
13
7. NOMENCLATURE AND FUNCTIONS
[Front]
The gure represents the A-3648D.

8
[Rear]
10.Network connection conrmation indicator
(Green)
An indicator to identify the unit using a web
browser.
• Flashes for 5 seconds when the identication
conrmation is performed using a web browser.
• Flashes 3 times when the unit is started up.
• Lights when in the manual mode.
( See the separate setup manual, which can be
downloaded from the TOA DATA Library (https://
www.toa-products.com/international/).)
11. Emergency broadcast indicator (Red)
Lights while the emergency broadcast is in progress.
( See "PRIORITY BROADCAST FUNCTION" on
p. 22.)
12. Priority broadcast indicator (Green)
Lights while the priority broadcast is in progress.
( See "PRIORITY BROADCAST FUNCTION" on
p. 22.)
13. CPU running indicator (Green)
Lights while the CPU is running.
14. Volume control knobs for Inputs 1 through 7
Adjust the volume values of the Inputs 1 through 7.
Rotate each knob clockwise to increase the
volume value and counterclockwise to decrease it.
(See "VOLUME ADJUSTMENT" on p. 20.)
15. Bass control knob
Rotate the knob clockwise to boost the bass and
counterclockwise to cut it.
Setting the knob at the center makes the frequency
characteristic at.
16. Treble control knob
Rotate the knob clockwise to boost the treble and
counterclockwise to cut it.
Setting the knob at the center makes the frequency
characteristic at.
17. Master volume control knob
Adjusts all the volume levels simultaneously.
Rotate the knob clockwise to increase the whole
volume level and counterclockwise to decrease it.
(See "VOLUME ADJUSTMENT" on p. 20.)
31
30
2625 27 28 29
32 40 41 42
18 19
39
35
21
22
34 37 38
20
23 24
36
33
The gure represents the A-3648D.

9
18. AC inlet
Connect the supplied power cord to this
receptacle.
Be sure to use the supplied power cord.
Using any other power cord may cause
electric shock.
WARNING
19. DIP switch
• Switches 1 and 2 (Chime tone setting switch)
Set the chime tone to be used.
(See "Chime Tone Setting" on p. 19.)
• Switch 3 (Line output interlock switch)
Sets an interlock between the zone selection
and the line output.
( See "Line Output Interlock Switch Setting" on
p. 19.)
• Switches 4 through 6
Not used.
20. Remote master volume control terminal
Short-circuit current: 10 mA or less, open voltage :
35 V DC or less, removable terminal block
(3.50 mm, 4 pins)
Sound volume can be adjusted by connecting the
10 kΩ B-taper potentiometer.
( See "Connecting to the Remote Master Volume
Control Terminal" on p. 15.)
21. Power remote control output terminal
Open collector output, withstand voltage: 30 V
DC or less, current: 25 mA or less, removable
terminal block (3.50 mm, 4 pins)
An output terminal that can be used for remote
control of other equipment. Operates in
synchronization with the unit’s power ON/OFF.
When the unit’s power is on, it is activated.
22. Emergency control output terminal
Open collector output, withstand voltage: 30 V
DC or less, current: 25 mA or less, removable
terminal block (3.50 mm, 4 pins)
An output terminal that can be used for remote
control of other equipment.
It is activated during the emergency broadcast
made from the unit.
23. Chime volume control knob
Adjusts the chime volume.
Rotate the knob clockwise to increase the chime
volume and counterclockwise to decrease it.
24. Ducker depth control knob
Adjusts the automatically attenuated level of the
sound volume on the BUS 2 while the broadcast
is being made using the BUS 1.
Rotate the knob clockwise to increase the
attenuation on the BUS 2 and counterclockwise
to decrease it. (See "DUCKER DEPTH
ADJUSTMENT" on p. 19.)
25. Input setting switches (Inputs 3 and 4)
Set whether or not to supply phantom power to
the microphones connected to Inputs 3 and 4 (26).
Tip
Phantom power is a 24 V DC.
26. Input terminals (Inputs 3 and 4)
–60 dB*, 600 Ω, electronically-balanced,
removable terminal block (3.81 mm, 3 pins)
Input terminals dedicated for microphones
27. Input setting switches (Inputs 1 and 2)
Set the input sensitivity level (LINE or MIC) of
the Inputs 1 and 2 (28). When switched to the
microphone input, set the phantom power to ON
or OFF.
Switch position Input specication at the
time of setting
MIC PHANTOM ON –60 dB*, 600 Ω,
phantom power ON
PHANTOM OFF –60 dB*, 600 Ω,
phantom power OFF
LINE –20 dB*, 600 Ω,
with no phantom power
Tip
Phantom power is a 24 V DC.
28. Input terminals (Inputs 1 and 2)
–20 dB* (LINE)/-60 dB* (MIC), 600 Ω, electronically-
balanced, removable terminal block (3.81 mm, 3
pins)
Input sensitivity can be switched either to the
Line input sensitivity or the Microphone input
sensitivity.
The input sensitivity can be changed with the
Input setting switch (27).
29. Control input terminals
(Control inputs 1 through 4)
Short-circuit current: 10 mA or less, open voltage:
35 V DC or less, Removable terminal block
(3.81 mm, 4 pins)
Input the control signals for controlling the priority
broadcast.
While the terminals are closed, the corresponding
trigger of the priority broadcast becomes input
state.
30. Functional ground terminal
Noise may be generated when external equipment
is connected to the unit. In this case, connect
this terminal to the functional ground terminal of
the external equipment, and the noise may be
reduced.
Note
This ground is not for protective ground.
* 0 dB = 1 V

10
*1 In case of the A-3606D: 8 – 16 Ω
*2 0 dB = 1 V
31. Speaker output terminal
Removable terminal block (5.00 mm, 6 pins)
Outputs the audio signals of the MAIN output or
power amplifier output. (See "BLOCK DIAGRAM"
on p. 30.)
When the Zone 1 is selected, audio signals are
output from the Zone 1 speaker output terminal.
In the same manner, when the Zone 2 is selected,
audio signals are output from the Zone 2 speaker
output terminal.
When set to High impedance, audio signals are
always output from the Direct speaker output
terminal regardless of the Zone selection button
setting.
Zone 1
speaker output terminal
Zone 2
speaker output terminal
Direct
speaker output terminal
C Terminal
*1
The table below shows the specications of each
output.
A-3606D A-3612D A-3624D A-3648D
Rated output 60 W 120 W 240 W 480 W
Low impedance 8 to 16 Ω 4 to 16 Ω
High impedance
(100 V line) 170 Ω 83 Ω 42 Ω 21 Ω
Notes
• Never use the low impedance and high
impedance terminals simultaneously. Doing so
may cause damage to the unit or the peripheral
equipment.
• Never make connection to low impedance
terminal when the Impedance setting switch
(32) is set to 100 V.
Tip
To change impedance between high and low, use
the Impedance setting switch (32).
32. Impedance setting switch
Changes the speaker output impedance either to
low or high.
100 V: High impedance
4 – 16 Ω*1: Low impedance
Notes
• Make sure that the power is switched OFF
before changing this switch setting. Change
cannot be performed when the power is on.
• The impedance remains as it is even if you
change the switch setting when the power is
ON. However, the impedance will change when
you turn the power ON again after turning the
power OFF.
33. Zone control input terminals
Short-circuit current: 10 mA or less, open voltage:
35 V DC or less, Removable terminal block
(3.81 mm, 4 pins)
Input the control signals for selecting zones. While
the terminals are closed, the corresponding zone
becomes in selected state, disabling operation of
the Zone selection button(5).
Note
Zone control is effective only when the output
impedance setting switch (32) is set to 100 V line
(high impedance).
34. Zone control output terminals
Open collector output, withstand voltage: 30 V
DC or less, current: 25 mA or less, Removable
terminal block (3.81 mm, 4 pins),
Output terminals for using the remote control of
other equipment. The terminal corresponding to
the selected zone is closed.
Note
Zone control is effective only when the output
impedance setting switch (32) is set to 100 V line
(high impedance).
35. Network terminal
RJ45 jack
Connect this terminal to the 100BASE-TX network
using a STP Category 5 or greater straight
through cable. A PC can be connected directly to
this terminal without using a hub.
36. Line output jacks 1 and 2
0 dB*2, 600 Ω, unbalanced type, RCA pin jack x 2
Can be interlocked with the zone selection state.
Signals are output from the Line output jacks 1
and 2 regardless of the zone selection when the
Line output selection interlock is set to OFF. With
the Line output interlock set to ON, the signals
are output from the Line output jack 1 when the
Zone 1 is selected, and from the Line output jack
2 when the Zone 2 is selected.
Use the DIP switch (19) to make the interlock
setting.
37. Recording output jack
0 dB*2, 600 Ω, unbalanced type, RCA pin jack
Outputs the audio signals of the SUB output. (See
"BLOCK DIAGRAM" on p. 30.)
Used to record the broadcast contents by
connecting the external recording device to this
jack.

11
38.Poweramplierinputjack
0 dB*, 600 Ω, unbalanced type, RCA pin jack
Input the output of the signal processor or other
devices connected to the line output jack. (See
"Connecting the External Equipment between the
Line Output and the Power Amplier" on p. 17.)
Connecting a pin plug to this jack disconnects
the power amplier section from the preamplier
section inside the unit.
39. Input 7 jacks
–20 dB*, 10 kΩ, unbalanced type, RCA pin jack x 2
Input jacks dedicated for LINE
40. BUS setting switches
Set which to send the audio signals input from the
Inputs 5 and 6 to the BUS 1 or 2 using the slide
switches.
(See "BLOCK DIAGRAM" on p. 30.)
Output destination
selection switch Usable input terminal
BUS 1 BUS 1 input terminal
( Removable terminal block)
BUS 2 BUS 2 input terminal
(RCA pin jack x 2)
41. Input terminals dedicated for BUS 2
(Inputs 5 and 6)
–20 dB*, 10 kΩ, unbalanced type, RCA pin jack x 2
To use these jacks, select "BUS 2" with the BUS
setting switches (40).
(See "BLOCK DIAGRAM" on p. 30)
42. Input terminals dedicated for BUS 1
(Inputs 5 and 6)
–60 dB*, 600 Ω, electronically-balanced,
removable terminal block (3.81 mm, 3 pins)
To use these terminals, select "BUS 1" with the
BUS setting switches (40).
(See "BLOCK DIAGRAM" on p. 30.)
* 0 dB = 1 V

12
8. CONNECTIONS
External cable wiring must be only carried out by qualified and trained personnel.
8.1. Speaker Connection
For cable wiring to the removable terminal block, refer to p. 18.
Notes
• Never make connection to both 4 – 16 Ω* (low impedance) and 100 V line
(high impedance) terminals simultaneously.
• Never make connection to 4 – 16 Ω* terminal when the Impedance setting
switch is set to 100 V.
Tips
• Either C terminal can be used for connection.
• Recommended speaker cable is IV or HIV cable with thickness described
below.
Solid copper cable: ø0.32 – 2.0 mm
Stranded copper cable: 0.05 – 3.3 mm (AWG 30 – 12)
[Low impedance connection]
Speaker output terminal
A-3606D/3612D/3624D/3648D
4 to16 Ω*
*
[High impedance connection]
Combined impedance:
170 Ω (A-3606D)
83 Ω (A-3612D)
42 Ω (A-3624D)
21 Ω (A-3648D)
100 V line
100 V line
100 V line
*
*In case of the A-3606D: 8 – 16 Ω
For the audio output at high impedance application setting,
refer to "31. Speaker output terminal" on p. 10.

13
8.2. Input Terminal Connections and Settings
8.2.1. Connections
The terminal used for each of the Inputs 5 and 6 differs depending on the Input setting switch (Refer to the next
page.).
Connect the cable to the correct terminal according to the input terminal to use.
[Inputs 1 through 6 (Inputs 5 and 6 connections are for routing to BUS 1)]
(When connecting a 2-core shielded cable)
For cable wiring to the removable terminal plug, refer to p. 18.
[Inputs 5 through 7 (Inputs 5 and 6 connections are for routing to BUS 2)]
(When connecting a single core shielded cable)
Inputs 3 and 4
Removable terminal block
Inputs 1 and 2
Removable terminal block
Input 7
RCA pin jack
Inputs 5 and 6
Removable terminal block
Inputs 5 and 6
RCA pin jack
A-3606D/3612D/3624D/3648D

14
8.2.2. Inputs 1 through 6 settings
Each of Inputs 1 through 6 has its own setting switch corresponding to each input. Perform their settings as
shown below as needed.
[Inputs 1 and 2]
Set the sound source level to connect and whether or not to use the phantom power when the microphone input
is selected.
A-3606D/3612D/3624D/3648D
Input sound source Switch position Input specication
Line level LINE –20 dB*, 600 Ω
Microphone level, phantom power not required MIC – PHANTOM OFF (Factory-preset) –60 dB*, 600 Ω
Microphone level, phantom power required MIC – PHANTOM ON –60 dB*, 600 Ω
[Inputs 3 and 4]
Set whether or not to use phantom power on the Inputs 3 and 4 (dedicated microphone inputs).
Phantom power when needed: ON
Phantom power when not needed: OFF (Factory-preset)
A-3606D/3612D/3624D/3648D
Input specications: –60 dB*, 600 Ω, electronically balanced
[Inputs 5 and 6]
Set which to send the input audio signals to BUS 1 or BUS 2.
Operation when the ducker function works is different between BUS 1 and BUS 2.
(Refer to "DUCKER DEPTH ADJUSTMENT" on p. 19.)
[Input setting switches]
When sending to BUS 1: BUS 1
When sending to BUS 2: BUS 2 (Factory-preset)
A-3606D/3612D/3624D/3648D
Input specications: –60 dB*, 600 Ω, electronically balanced, removable terminal block (3.81 mm, 3 pins) (when
outputting to BUS 1)
–20 dB*, 10 kΩ, unbalanced, RCA pin jack (when outputting to BUS 2)
* 0 dB = 1 V

15
8.3. Connecting to the Remote Master Volume Control Terminal
You can adjust the volume level by remote control when an external volume control is connected to the unit.
To remotely control the volume level, adjust the unit’s volume level with the master volume control knob in
advance. The level adjusted with the master volume control knob is the maximum volume level that you can
remotely control.
For cable wiring to the removable terminal plug, refer to p. 18.
Note
Never set the master volume control knob to the minimum position. If set to the minimum, no sound is output
even if you maximize the volume level through this terminal.
(Refer to "VOLUME ADJUSTMENT" on p. 20.)
A-3606D/3612D/3624D/3648D
Connectable volume controller: 10 kΩ B-taper potentiometer
8.4. Connecting to the Power Remote Control Output Terminal
Use this terminal when remotely controlling other equipment. This terminal is activated when the unit is turned
ON.
For cable wiring to the removable terminal plug, refer to p. 18.
A-3606D/3612D/3624D/3648D
To other equipment’s
remote control input terminal
Output specications: Open collector output, withstand voltage: 30 V DC or less, current: 25 mA or less

16
8.5. Connecting to the Emergency Control Output Terminal
Use this terminal when remotely controlling other equipment. This terminal is activated while the emergency
broadcast is in progress from this unit.
For cable wiring to the removable terminal plug, refer to p. 18.
A-3606D/3612D/3624D/3648D
To other equipment's
remote control input terminal
Output specications: Open collector output, withstand voltage: 30 V DC or less, current: 25 mA or less
8.6. Connecting to the Zone Control IN/OUT Terminal
Zone can be selected by a control signal (make contact).
These terminals also output a control signal (logic low) when the zone is in selected state. They can be used
for remotely controlling other equipment.
Note
Zone control is effective only when the output impedance setting switch is set to 100 V line (high impedance).
For cable wiring to the removable terminal plug, refer to p. 18.
Zone 1 control input Zone 1 control output
Zone 2 control input Zone 2 control output
A-3606D/3612D/3624D/3648D
Control input signal specications: Short-circuit current: 10 mA or less, open voltage: 35 V DC or less
Control output signal specications: Open collector output, withstand voltage: 30 V DC or less, current: 25 mA
or less

17
8.7. Connecting to the Control Input Terminal
Priority broadcast can be controlled by inputting the contact signal to these terminals.
For the priority setting, refer to the separate setup manual, which can be downloaded from the TOA DATA
Library (https://www.toa-products.com/international/).
For cable wiring to the removable terminal plug, refer to p. 18.
A-3606D/3612D/3624D/3648D
Input 2
Input 4 Input 3
Input 1
Input signal specications: Short-circuit current: 10 mA or less, open voltage: 35 V DC or less
8.8. Connecting the External Equipment between the Line Output and the Power Amplifier
Appropriate sound can be obtained by connecting a signal processor like an equalizer or limiter between the
unit’s preamplier section (Line output jack) and the power amplier section (Power amplier input jack).
Notes
• When using the signal processor, be sure to turn OFF the unit’s line output interlock switch.
• Inserting a pin plug into the unit’s power amplier input jack disconnects the preamplier section from the
power amplier section inside the unit.
Tip
Either Line output 1 or 2 can be used.
IN
OUT
Signal processor
A-3606D/3612D/3624D/3648D
Line output specications: 0 dB*, 600 Ω, unbalanced, RCA pin jack
Power amplier input specications: 0 dB*, 600 Ω, unbalanced, RCA pin jack
* 0 dB = 1 V

18
8.9. Removable Terminal Plug Connection
Step 1. Wiring the supplied removable terminal plug.
1-1. Loosen the terminal screws to insert the wire.
1-2. Tighten the terminal screws.
Ensure that the wire does not break free when
pulled. If the wire does pull free, repeat the
connection procedure from the start.
Step 2. Insert the wired terminal plug into the corresponding
terminal block in the unit’s rear panel.
Step 3. Only when the xing screw is inserted, tighten the
xing screw.
Notes
• Do not reverse Steps 1 and 2 above. Poor contact may
result if force is applied to the unit’s internal circuit board
pins while the terminal screws are being tightened.
• When detaching the terminal plug, pull it straight out. Pulling
it out at an angle may cause the terminal plug or terminal
block to break.
Slotted screwdriver
LoosensTightens
Removable terminal plug
(accessory)
Terminal screw
Fixing screw
1
[Recommended type of screwdriver ]
Blade width*1
*1For speaker output terminal: About 3.5 mm
For other terminals: About 2.5 mm
Tips
• Applicable cable size
For speaker output terminal For other terminals
Conductor cross-section area 0.05 − 3.3 mm20.08 − 2.0 mm2
AWG AWG 30 − 12 or equivalent AWG 28 − 14 or equivalent
Solid cable and stranded cable Shielded cable
7 mm*27 mm*2
20 mm
*2 Expose 8 mm or more when using the above
ferrule terminal, and cut off an extra conductor
protruding from the sleeve.
Note
Avoid soldering stranded or shielded
cable, as contact resistance may increase
when the cable is tightened and the
solder is crushed, possibly resulting in an
excessive rise in joint temperatures.
• When connecting 2 cables or a shielded cable to a single terminal, use a ferrule terminal with an insulation
sleeve to crimp the cables because such cable conductors could become loose.
(1) Recommended ferrule terminals for signal cables
(made by Phoenix Contact)
Model Number a l1l2
AI 0,34-8 TQ
AI 0,5-8 WH
2
Unit: mm
2.5
12.5
14
8
8
b
0.8
1.1
(2) Recommended ferrule terminals for speaker cables
(made by Phoenix Contact)
Model Number a1l1l2
AI 1,5-8 BK
AI-TWIN 2x1,5-8 BK 6.6
a2
3.6
14
162.3
8
8
a
3.4
Unit: mm
b
1.8
Crimping tool: CRIMPFOX 10S (made by Phoenix Contact)
Insulation sleeve
Contact section
Insulation sleeve
Contact section
a
l2
a1
a2
l1
l2
l1
bb
• Cable sheath to trim

19
9. SETTINGS
9.1. Chime Tone Setting
Set the chime tone to use with the DIP switches 1 and 2.
A-3606D/3612D/3624D/3648D
Chime tone to use Switch 1 Switch 2 Switch’s gures
4-note
(Factory-preset) OFF OFF 1 2 3 4 5 6
2-note ON OFF 1 2 3 4 5 6
1-note OFF ON 1 2 3 4 5 6
Not used ON ON 1 2 3 4 5 6
9.2. Line Output Interlock Switch Setting
Set the interlock between zone selection and line output using Switch 3 of the DIP switch.
A-3606D/3612D/3624D/3648D
OFF: Signals are output from the Line output jacks 1 and 2 regardless of zone selection. (Factory-preset)
ON: Signals are output from the Line output jack 1 when the Zone 1 is selected and from the Line output jack
2 when the Zone 2 is selected.
10. DUCKER DEPTH ADJUSTMENT
The unit is equipped with Ducker function. When broadcast is made through BUS 1, the volume level of the
audio signals input to BUS 2 is automatically attenuated.
Each input is sent to either BUS 1 or BUS 2 as shown below.
Input No. Input destination
Inputs 1 through 4 BUS 1
Inputs 5 and 6 BUS 1 or BUS 2 selectable
Input 7 BUS 2
Attenuation amount can be adjusted with the Ducker depth control knob. Rotate the knob clockwise to increase
the attenuation amount and counterclockwise to decrease it.

20
When signals stop entering BUS 1, the volume level on BUS 2 automatically returns to its original level.
(Refer to "BLOCK DIAGRAM" on p. 30.)
BUS 1
broadcast start
BUS 1
broadcast end
BUS 2 broadcast
in progress
Volume
level
Attenuation amount
Small
Large
BUS 2 volume level slowly
returns to its original level.
Time
Attenuation
amount: small
Attenuation
amount: large
Ducker depth
Note
When the knob is rotated fully
counterclockwise, the volume level of
BUS 2 signals such as BGM will not
decrease.
11. VOLUME ADJUSTMENT
The unit’s volume value can be adjusted in 4 steps with the different means as described below.
• Inputs 1 to 7 volume control knobs
• Software master volume control
• Remote master volume control
• Master volume control knob
Master volume
control knob
Remote master
volume control
Software master
volume control
Input 1
Volume control knob
Input 7
Volume control knob
If any one of the volume controls is set to the minimum, no sound is output even if other volume control is set to
the maximum. If you intend to adjust the volume value with the Software master volume control*1 or the Remote
master volume control (see p. 15), adjust the volume value using the master volume control knob in advance.
The value adjusted with the master volume control knob is the adjustable upper limit.
When set to the Emergency broadcast, the broadcast is made at the maximum level regardless of the set
values of the master volume, software master volume, and remote master volume*2. Also, the chime is sounded
at the maximum volume, and the characteristics of the EQ, tone control, and bass control are made at.
The front-mounted emergency broadcast indicator lights during emergency broadcast, making the Emergency
control output terminal closed.
*1 Adjust the Software master volume control using the browser. For details, refer to the separate setup manual,
which can be downloaded from the TOA DATA Library (https://www.toa-products.com/international/).
*2 Volume control knobs for each input remain effective.
12. SPEAKER ZONE SELECTION
Pressing the unit’s front-mounted Zone 1 selection switch or inputting the control signal to the Zone 1 control
input terminal allows the Zone 1 indicator to light and the broadcast to be output from the speakers connected
to the rear-amounted Zone 1 speaker output terminal. Concurrently, the control signal is output from the Zone
1 control output terminal.
Operation in the case of Zone 2 is the same as above.
Note
Speaker zone control is effective only when the impedance setting switch (p. 10) is set to 100 V line (high
impedance).
When set to High impedance, audio signals are always output from the Direct speaker output terminal regardless
of the Zone selection button setting.