Toa D-901 User manual

INSTRUCTION MANUAL
DIGITAL MIXER D-901
(Version 2)
Thank you for purchasing TOA's Digital Mixer.
Please carefully follow the instructions in this manual to ensure long, trouble-free use of your equipment.

2
TABLE OF CONTENTS
1. SAFETY PRECAUTIONS ............................................................................... 6
2. GENERAL DESCRIPTION ............................................................................. 7
3. FEATURES .......................................................................................................... 7
4. HANDLING PRECAUTIONS .......................................................................... 7
5. NOMENCLATURE AND FUNCTIONS
5.1. D-901 Digital Mixer
Front .................................................................................................................. 8
Rear ................................................................................................................. 11
5.2. Optional Modules
5.2.1. D-921F Microphone/Line Input Module .................................................. 12
5.2.2. D-921E Microphone/Line Input Module ................................................. 12
5.2.3. D-922F Microphone/Line Input Module .................................................. 12
5.2.4. D-922E Microphone/Line Input Module ................................................. 13
5.2.5. D-936R Stereo Input Module ................................................................. 13
5.2.6. D-971M Line Output Module .................................................................. 13
5.2.7. D-971E Line Output Module .................................................................. 14
5.2.8. D-971R Line Output Module .................................................................. 14
5.2.9. D-981 Remote Control Module .............................................................. 14
6. SETTING BASICS
6.1. Setting Procedures .......................................................................................... 15
6.2. Setting Flowcharts
6.2.1. Input and output settings ........................................................................ 16
6.2.2. Microphone bus settings ........................................................................ 19
6.2.3. Preset memory settings ......................................................................... 19
6.2.4. utility settings ......................................................................................... 20
6.3. Setting Keys and Knob .................................................................................... 21
6.4. Setting Screen Displays ................................................................................... 22
7. INPUT/OUTPUT GAIN SETTINGS
7.1. Input and Output Channel Control Section Settings ........................................ 23
7.2. Input/Output Gain Setting Screen Operation ................................................... 23
7.3. Input/Output Channel Gain Setting Screen Operation ..................................... 23
8. INPUT-RELATED SETTINGS
8.1. Phantom Power ON/OFF Settings (Only with D-921E or D-921F module) ..... 24
8.2. PAD (Input Sensitivity) Settings (Only with D-921E or D-921F module) .......... 24
8.3. Line Input Mode Selection (Only with D-936R module) ................................... 24
8.4. Line (Stereo) Input Selection (Only with D-936R module) ............................... 25
8.5. Input Trim Settings
8.5.1. Input trim gain settings ........................................................................... 25
8.5.2. Input trim polarity settings ...................................................................... 25
8.6. High-Pass Filter Settings
8.6.1. Cutoff frequency settings ....................................................................... 26
8.6.2. Q settings ............................................................................................... 26
8.7. Equalizer Settings
8.7.1. Gain settings .......................................................................................... 27
8.7.2. Center frequency settings ...................................................................... 27
8.7.3. Q settings ............................................................................................... 27

3
8.8. Compressor/Auto-Leveler Mode Selection ...................................................... 28
8.9. Compressor Settings
(only when the compressor mode is selected in Section 8.8.)
8.9.1. Threshold level settings ......................................................................... 28
8.9.2. Ratio settings ......................................................................................... 29
8.9.3. Attack time settings ................................................................................ 29
8.9.4. Release time settings ............................................................................. 29
8.9.5. Makeup gain settings ............................................................................. 29
8.10. Auto-Leveler Settings
(only when the auto-leveler mode is selected in Section 8.8)
8.10.1. Target level settings ............................................................................. 30
8.10.2. Maximum gain settings ........................................................................ 30
8.10.3. Attack time settings .............................................................................. 30
8.10.4. Release time settings ........................................................................... 31
8.11. Level Sense Settings
8.11.1. Attack time settings .............................................................................. 31
8.11.2. Release time settings ........................................................................... 31
8.12. Gate Settings
8.12.1. Threshold level settings ....................................................................... 32
8.12.2. Hysteresis settings ............................................................................... 32
8.12.3. Depth settings ...................................................................................... 33
8.12.4. Hold time settings ................................................................................ 33
8.12.5. Attack time settings .............................................................................. 33
8.12.6. Release time settings ........................................................................... 33
8.13. Auto-Mixing Group Settings ............................................................................. 34
8.14. Ducker Settings
8.14.1. Priority settings .................................................................................... 35
8.14.2. Attenuation settings ............................................................................. 35
8.14.3. Attack time settings .............................................................................. 36
8.14.4. Release time settings ........................................................................... 36
8.15. NOM Attenuation ON/OFF Settings ................................................................. 36
8.16. Input Channel Gain Settings ............................................................................ 37
8.17. Input Channel Group Trim Gain Settings (Only when Group is set) ................ 37
8.18. Bus Assignment and Crosspoint Gain Settings
8.18.1. Bus assignment settings ...................................................................... 38
8.18.2. Crosspoint gain settings ....................................................................... 38
9. OUTPUT SETTINGS
9.1. Output Channel Gain Settings ......................................................................... 39
9.2. Output Channel Group Trim Gain Settings (Only when Group is set) ............. 39
9.3. Crossover Settings (Only when Crossover function is enabled)
9.3.1. Slope settings ........................................................................................ 40
9.3.2. Cutoff frequency settings ....................................................................... 41
9.3.3. Q settings ............................................................................................... 41
9.3.4. Q2 settings ............................................................................................. 41
9.3.5. Crossover gain settings ......................................................................... 41
9.3.6. Crossover filter polarity settings ............................................................. 41
9.4. Filter Settings ................................................................................................... 42
9.4.1. Parametric equalizer .............................................................................. 44
9.4.2. High-pass filter ....................................................................................... 44
9.4.3. Low-pass filter ........................................................................................ 45
9.4.4. High shelving filter .................................................................................. 45
9.4.5. Low shelving filter .................................................................................. 45
9.4.6. Horn equalizer ........................................................................................ 46
9.4.7. Notch filter .............................................................................................. 46

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9.4.8. All-pass filter .......................................................................................... 46
9.5. Compressor Settings
9.5.1. Threshold level settings ......................................................................... 47
9.5.2. Ratio settings ......................................................................................... 47
9.5.3. Attack time settings ................................................................................ 48
9.5.4. Release time settings ............................................................................. 48
9.5.5. Makeup gain settings ............................................................................. 48
9.6. Delay Time Settings ......................................................................................... 48
10. MICROPHONE BUS SETTINGS
10.1. Feedback Suppression Settings
10.1.1. Dynamic mode settings ...................................................................... 49
10.1.2. Auto mode activation ......................................................................... 50
10.1.3. Filter number settings ........................................................................ 50
10.1.4. Dynamic mode filter initialization ........................................................ 50
10.1.5. Auto mode filter initialization .............................................................. 50
10.2. Feedback Suppression Filter Setting Confirmation
10.2.1. Mode confirmation ............................................................................. 51
10.2.2. Frequency confirmation ..................................................................... 51
10.2.3. Filter gain confirmation ....................................................................... 51
10.2.4. Q confirmation .................................................................................... 51
10.3. Effect (Echo) Settings
10.3.1. Echo gain settings .............................................................................. 52
10.3.2. Feedback ratio settings ...................................................................... 52
10.3.3. Feedback delay settings .................................................................... 52
10.3.4. Initial echo (pre-) delay settings ......................................................... 53
10.3.5. Low-pass filter frequency settings ...................................................... 53
10.3.6. Low-pass filter Q settings ................................................................... 53
10.4. Bus Assignment and Crosspoint Gain Settings
(Microphone Bus →→Output Channel)
10.4.1. Bus assignment settings .................................................................... 53
10.4.2. Crosspoint gain settings ..................................................................... 53
11. PRESET MEMORY SETTINGS
11.1. Preset Memory Save ..................................................................................... 54
11.2. Preset Memory Recall .................................................................................... 54
11.3. Preset Memory Delete ................................................................................... 55
11.4. Initial Preset Memory Selection ..................................................................... 55
11.5. Configuration Save ........................................................................................ 55
12. UTILITY SETTINGS
12.1. Stereo Link Settings ....................................................................................... 56
12.2. Group Settings ............................................................................................... 56
12.3. Crossover Configuration Settings .................................................................. 57
12.4. NOM Attenuation Settings ............................................................................. 59
12.5. Contact Input/Output Settings (Only when the D-981 is used)
12.5.1. Function assignment to the input contact .......................................... 60
12.5.2. Function assignment to the output contact ........................................ 62
12.6. Protect Settings .............................................................................................. 63
12.7. RS-232C Port Settings
12.7.1. Control mode selection ...................................................................... 65
12.7.2. RS-232C transmission rate settings .................................................. 65
12.8. All Input/Output Channel Gain Confirmation .................................................. 66

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12.9. Module Type Confirmation
12.9.1. Individual slots confirmation ............................................................... 66
12.9.2. All slots confirmation .......................................................................... 67
12.10. Cooling Fan Operating Status Confirmation .................................................. 67
12.11. Firmware Version Confirmation ..................................................................... 67
13. RESTORING FACTORY DEFAULT SETTINGS ..................................... 68
14. FIRMWARE UPDATE ...................................................................................... 68
15. RACK MOUNTING ........................................................................................... 70
16. CONNECTIONS
16.1. Connection Example 1 ................................................................................... 71
16.2. Connection Example 2 (Broadcasting to two separate zones) ...................... 72
16.3. Removable Terminal Plug Connection .......................................................... 73
17. BLOCK DIAGRAM ........................................................................................... 74
18. LEVEL DIAGRAM ............................................................................................ 75
19. PARAMETER SETTING ITEMS AND SETTING RANGES ................ 76
20. SPECIFICATIONS
20.1. D-901 Digital Mixer ........................................................................................ 80
20.2. D-921F Microphone/Line Input Module (Optional) ......................................... 81
20.3. D-921E Microphone/Line Input Module (Optional) ......................................... 81
20.4. D-922F Microphone/Line Input Module (Optional) ......................................... 81
20.5. D-922E Microphone/Line Input Module (Optional) ......................................... 82
20.6. D-936R Stereo Input Module (Optional) ........................................................ 82
20.7. D-971M Line Output Module (Optional) ......................................................... 82
20.8. D-971E Line Output Module (Optional) .......................................................... 83
20.9. D-971R Line Output Module (Optional) ......................................................... 83
20.10. D-981 Remote Control Module (Optional) ..................................................... 84

6
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 fire or electric shock.
• Use the unit only with the voltage specified on the
unit. Using a voltage higher than that which is
specified may result in fire 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 fire or
electric shock.
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 fire 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 fire
or electric shock.
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 fire or electric
shock.
• Do not block the fan exhaust vent on the unit's rear
and the ventilation slots on the bottom. Doing so
may cause heat to build up inside the unit and
result in fire.
• 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 fire or
electric shock.
• When installing the unit in an equipment rack,
observe the following instructions. Failure to do so
may result in fire or personal injury.
· Install the rack on a solid and stable surface.
Then, secure it with anchor bolts or make other
appropriate arrangements to prevent it from
falling down or moving.
· Use the screws supplied with the unit to mount on
TOA's rack.
· The AC outlet to which the unit's AC power cable
is connected must have allowable current
capacity over the unit's current consumption.
When the Unit is in Use
• 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 fire or electric
shock.
1. SAFETY PRECAUTIONS
• Be sure to read the instructions in this section carefully before use.
• Make sure to observe the instructions in this manual as the conventions of safety symbols and messages
regarded as very important precautions are included.
• We also recommend you keep this instruction 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 first and
understand the safety symbols and messages so you are thoroughly aware of the potential safety hazards.
WARNING
Indicates a potentially hazardous situation which, if mishandled, could
result in death or serious personal injury.
Indicates a potentially hazardous situation which, if mishandled, could
result in moderate or minor personal injury, and/or property damage.
WARNING
CAUTION
CAUTION

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2. GENERAL DESCRIPTION
TOA's D-901 is a 19-inch rack-mounted (3U high) digital mixer configured with 12 inputs, 8 buses, and 8
outputs. It features signal processing functions necessary for sound systems such as feedback suppression
and auto-mixing. All functional parameters can be set at the unit*. Settings can be stored in the unit's internal
memory as "preset memory" and can be recalled using the front panel-mounted operation keys.
* Can also be set at a PC using the setting software, which can be downloaded from our website
"http://www.toa-products.com/international/".
3. FEATURES
• Acoustic feedback can be suppressed through simple operation.
• Auto-Mixing functions (Ducker*1and NOM Attenuation*2) automatically adjust the input signal volume.
• Signals are digitally processed, ensuring high-accuracy sound parameter settings.
• All settings can be performed at the unit using the LCD screen and setting keys and knobs located on the
front panel. The settings can also be made at a PC using the dedicated software.
• Modular construction permits flexible configuration of inputs and outputs, from 2-IN/4-OUT to 12-IN/8-OUT
systems.
• Up to 16 preset patterns can be stored in memory, which can be easily recalled from either the unit or
connected external equipment.
• An RS-232C port permits remote control of the unit using an AMX or Crestron controllers, or similar external
equipment. The control protocol is available for download at our website http://www.toa-
products.com/international/.
• A protect function prevents accidental changes of front panel key settings.
• Optional D-981 Remote Control Module permits easy remote operation of volume control and preset
memory recall.
*1Automatically adjusts all channel gains in response to input signal level. (Refer to p. 35.)
*2Automatically adjusts the input gain of open microphones corresponding to the number of open
microphones in the system. (Refer to p. 36.)
Notes
• AMX is a trademark of AMX Corporation.
• Crestron is a trademark of Crestron Electronics, Inc.
4. HANDLING PRECAUTIONS
• Use the unit in locations where the temperature is between +5 to +40 °C (no condensation) and the humidity
is less than 90%.
• The D-901 is a precision audio component. To prevent failure, avoid locations where the unit may be
exposed to strong shocks or vibrations.
• To clean, be sure to first switch off the power, then wipe with a dry cloth. When extremely dirty, use a soft
cloth dampened in neutral detergent. Never use benzene, thinner or chemically-treated towels, which may
damage the unit's finish.

8
5. NOMENCLATURE AND FUNCTIONS
5.1. D-901 Digital Mixer
[Front]
ON
MIC BUS
FBS
EFFECT
UTILITY
8
7
6
5
1
2
3
4
5
612
11
10
9
8
7
PRESET INPUT OUTPUT
PARAMETER
DIGITAL MIXER model D-901
1
2
ON
POWER
OFF
ON
6
37
5
48
PRESET
PUSH-ENTER
CHANGE
LOCK
4
3
2
1
ENTRY SECTION
ON
SEL
+12dB
+6dB
0dB
-6dB
PEAK
-40dB
-20dB
-12dB
0N SIG SEL
SEL SIG 0N 0N SIG SEL
1 2
Parameter input section Input channel control section
Output channel
control section
Preset memory selection section Microphone bus control section
(described below) (Refer to p. 9.)
(Refer to p. 9.) (Refer to p. 10.)
(Refer to p. 10.)
1. Power switch [POWER, ON/ OFF]
The unit's power switches ON when this switch is
pressed, and switches OFF when pressed again.
2. Power Indicator
Lights when the power is switched ON.
Parameter Input Section
UTILITY PARAMETER
ONPRESET
PUSH-ENTER
CHANGE
LOCK
3 4 5 6 7
8 9 10 11 12
3. Utility Indicator
Remains lit during selection of the utility function.
4. Utility Key [UTILITY]
Selects the utility function. Pressing this key
displays the utility function setting screen on the
LCD screen (5). (Refer to p. 56.)
5. LCD Screen
When the function key is pressed, its
corresponding setting screen is displayed on this
screen. If the unit's internal cooling fan
malfunctions, the "ERROR indication appears on
the screen even during setting operation. In this
case, contact your TOA dealer.
6. System Lock Indicator [LOCK]
Lights when the protect function is enabled. (For
more information on the protect function, refer to
p. 63.)
Flashes when the D-901 is communicating with a
PC.
7. Setting Knob [CHANGE PARAMETER, PUSH-
ENTER]
This knob can be rotated to change parameters
or select setting contents, and also operates as a
push switch. Pressing the knob when the [OK?]
indication is displayed on the LCD screen (5)
enables the corresponding function.
8. Preset Indicator
Remains lit during preset memory selection.
9. Preset Key [PRESET]
Recalls the settings stored in preset memory or
saves the current parameters. The preset
memory setting screen appears on the LCD (5)
when this key is pressed. (Refer to p. 54.)
10. Screen Shift Keys [ ]
Pressing these keys change the setting items on
the LCD (5).
11. Function ON/OFF Indicator
Lights when the parameter shown on the LCD (5)
is enabled (ON).
12. Function ON/OFF Key [ON]
Parameters displayed on the LCD (5) are
enabled (ON) when this key is pressed, and
disabled (OFF) when pressed again.

9
Preset Memory Selection Section
13. Preset Memory Selector Keys [1 – 8]
Recall preset memory patterns 1 –8. To recall,
press the desired Preset Memory Selector key,
then press the Setting knob (7).
14. Preset Memory Indicators
The LED corresponding to the currently selected
Preset Memory Selection key is illuminated.
PRESET
1
26
37
5
48
13
14
1
2
3
4
5
612
11
10
9
8
7
INPUT
ON
SEL SIG 0N 0N SIG SEL
15
16 18 1917
Input Channel Control Section
Green: Signal level is between –40 dB and
+17 dB on the basis of the rated input
signal level.
OFF: Signal level is lower than –40 dB
below the rated input signal level.
Note
The indicator lights red when the signal level is
set too high. In such cases, decrease the output
level of connected equipment so that the
indicator lights green.
·ON: Lights when the channel is selected and
active.
17. Input Volume Control [INPUT]
Adjusts the gain of the input channel selected
with the Input Channel Selector keys (15).
18. Input Channel ON/OFF Key [ON]
Enables or disables the channel selected with the
Input Channel Selector keys (15).
19. Input Channel ON/OFF Indicator
Lights continuously to indicate that the input
channel selected with the Input Channel Selector
keys (15) is enabled (ON).
15. Input Channel Selector Keys [1 – 12]
Used to select the input channel for sound
volume adjustment or parameter setting. The
Input channel indicator [SEL] (16) lights when a
key is pressed, causing the corresponding
channel number to be displayed on the setting
screen.
16. Input Channel Indicators [SEL, SIG, ON]
·SEL: Lights when the input channel is selected.
·SIG
Indicates the input signal level in two colors (red
and green). The status of indicator shows as
follows depending on the input signal levels.
Red: Signal level is 17 dB or more above
the rated input signal level.
Rated input signal level
+17 dB
–40 dB
Input signal level
LED
Green
Red
OFF

10
Microphone Bus Control Section
Microphone bus indicator (21) to light, and allows
feedback suppression (p. 49), effect (echo) (p.
52), and bus assignment (p. 53) to be set on the
LCD screen.
21. Microphone Bus Indicator
Remains lit while the microphone bus is selected.
22. Feedback Suppression Indicator [FBS]
Remains lit while the feedback suppression
function is enabled.
23. Effect Key [EFFECT]
The effect (echo) function is enabled when this
key is pressed, and the effect (echo) parameters
are displayed on the LCD screen, allowing
settings to be changed. Pressing the key again
disables the effect (echo) function. (Refer to p.
52.)
24. Effect Indicator
Remains lit while the effect (echo) function is
enabled.
Output Channel Control Section
Note
The indicator lights red when the signal level is
set too high. In such cases, attenuate the unit's
output level so that the indicator lights green.
·SEL: Lights when the output channel is
selected.
27. Output Volume Control [OUTPUT]
Adjusts the gain of the output channel selected
with the Output Channel Selector keys (28).
28. Output Channel Selector Keys [1 – 8]
Used to select the output channel for sound
volume adjustment, parameter setting or Level
meter indication (25). The Output Channel
indicator [SEL] (26) lights when the key is
pressed, permitting parameter setting, volume
adjustment with the Output volume control (27) or
Level meter (25) signal level indication.
29. Output Channel ON/OFF Key [ON]
Enables or disables the channel selected with the
Output Channel Selector keys (28).
30. Output Channel ON/OFF Indicator
Lights continuously to indicate that the output
channel selected with the Output Channel
Selector keys (28) is enabled (ON).
25. Output Signal Level Meter
Indicates the signal level of the channel selected
with the Output Channel Selector keys (28).
26. Output Channel Indicators [ON, SIG, SEL]
·ON: Lights when the channel is active.
·SIG
Indicates the output signal level in two colors
(red and green). The status of indicator shows
as follows depending on the output signal
levels.
Red: Signal level is 17 dB or more above
the rated output signal level.
Green: Signal level is between –40 dB and
+17 dB on the basis of the rated
output signal level.
OFF: Signal level is lower than –40 dB
below the rated output signal level.
ON
8
7
6
5
OUTPUT
4
3
2
1
+12dB
+6dB
0dB
-6dB
PEAK
-40dB
-20dB
-12dB
0N SIG SEL
25
26
27
28
29
30
MIC BUS
FBS
EFFECT
SEL
21
22
23
24
20
20. Microphone Bus Selector Key [SEL]
Used to set the microphone bus parameters or
adjust the volume. Pressing this key causes the
Rated output signal level
+17 dB
–40 dB
Output signal level
LED
Green
Red
OFF

11
[Rear]
DIGITAL MIXER
model D-901
MADE IN JAPAN
TOA Corporation
GND
SIGNAL
RS-232C
31 32 33 34 35 36 37 38 39 40 41
42
Input module slot
Output module slot
Input & output module slot
Control module slot
Inputs
7 & 8
Inputs
5 & 6
Inputs
3 & 4
Inputs
1 & 2
Outputs
1 –4
Inputs 11
& 12 or
Outputs
5 –8
Inputs 9
& 10 or
Outputs
1 –4
Outputs
5 –8
Slot 9 Slot 8 Slot 7 Slot 6 Slot 5 Slot 4 Slot 3 Slot 2 Slot 1
31. Cooling Fan
32. RS-232C Communication Port
A communications connector for a personal
computer (PC) or other control equipment.
33. Control Module Slot
The control module's dedicated slot.
34. Output Module Slot
Slot for output channels 5 –8.
35. Output Module Slot
Slot for output channels 1 –4.
36. Input/Output Module Slot
Slot for input channels 11 and 12. Inserting an
output module here provides output signals for
channels 5 –8.
37.Input/Output Module Slot
Slot for input channels 9 and 10. Inserting an
output module here provides output signals for
channels 1 –4.
38. Input Module Slot
Slot for input channels 7 and 8.
39. Input Module Slot
Slot for input channels 5 and 6.
40. Input Module Slot
Slot for input channels 3 and 4.
41. Input Module Slot
Slot for input channels 1 and 2.
42. AC Inlet
Connect this inlet to the wall AC outlet using the
supplied power cord.
Note
Slots 5 –8 accommodate only two D-971M and/or D-
971E Line Output Modules together or independently
in total.
CAUTION
Do not block the fan exhaust vent. Doing so
may cause heat to build up inside the unit and
result in fire.

12
5.2. Optional Modules
Notes
•Make sure that the power is switched OFF before attaching or detaching modules.
•To avoid failures due to static electricity, do not touch the parts or terminals on the circuit board of both the
unit and module.
•Ensure that the module is installed and secured with screws in the correct position.
•Cover idle slots with the blank panels attached to the unit as shipped by the factory.
5.2.1. D-921F Microphone/Line Input Module
ACCESSORY I.T.E 78CK
GND LIFT
NORMAL
GND LIFT
NORMAL
2
1
MIC/LINE INPUT MODULE [–50 / –36 / –10 / +4 dB] model D-921F
43
44
1
2
3
: E
: H
: C
43. Monaural Input Terminal [1, 2] (XLR-3-31 equivalent)
Electronically-balanced input terminal. (Pin 1:
Ground; Pin 2: Hot; Pin 3: Cold)
Use XLR-3-12C or equivalent for connection.
Input sensitivity (–50/–36/–10/+4 dB) and
phantom power (+15 V) ON/OFF can be set by
way of the front panel setting screen.
44. Ground Lift Switch [GND LIFT/NORMAL]
Hum noise may be generated due to ground loops created when the unit
is connected to other equipment. Setting the switch to the GND LIFT
position cuts the ground loop.
2: Hot
1: Ground
3: Cold
5.2.2. D-921E Microphone/Line Input Module
45. Monaural Input Terminal [1, 2]
Electronically-balanced, removable terminal block. (H: Hot; C: Cold; E:
Ground)
Input sensitivity (–50/–36/–10/+4 dB) and phantom power (+15 V)
ON/OFF can be set by way the front panel setting screen.
46. Ground Lift Switch [GND LIFT/NORMAL]
Hum noise may be generated due to ground loops created when the unit
is connected to other equipment. Setting the switch to the GND LIFT
position cuts the ground loop.
ACCESSORY I.T.E 78CK
E
C
H
E
C
H
GND LIFT
NORMAL
GND LIFT
NORMAL
2
1
MIC/LINE INPUT MODULE [–50 / –36 / –10 / +4 dB] model D-921E
45
46
5.2.3. D-922F Microphone/Line Input Module
47. Monaural Input Terminal [1, 2] (XLR-3-31 equivalent)
Electronically-balanced input terminal. (Pin 1:
Ground; Pin 2: Hot; Pin 3: Cold)
Use XLR-3-12C or equivalent for connection.
48. Input Sensitivity Switch [PHANTOM, GND LIFT, MIC/LINE]
4-pole switch. Enables phantom
power (+15 V; ON/OFF, enabled
only when set to the MIC
position), ground lift and input
sensitivity.
Input sensitivity: –36 or –50 dB
(MIC mode) / –10 or +4 dB (LINE
mode)
ACCESSORY I.T.E 78CK
2
1
MIC/LINE INPUT MODULE model D-922F
OFF : PHANTOM
LIFT : GND
LINE
-36dB(MIC)
+4dB(LINE)
ON
NORMAL
MIC
-10dB(LINE)
-50dB(MIC)
OFF : PHANTOM
LIFT : GND
LINE
-36dB(MIC)
+4dB(LINE)
ON
NORMAL
MIC
-10dB(LINE)
-50dB(MIC)
47
48
1
2
3
: E
: H
: C
OFF : PHANTOM
LIFT : GND
LINE
-36dB(MIC)
+4dB(LINE)
ON
NORMAL
MIC
-10dB(LINE)
-50dB(MIC)
2: Hot
1: Ground
3: Cold

13
5.2.4. D-922E Microphone/Line Input Module
49. Monaural Input Terminal [1, 2]
Electronically-balanced, removable terminal block. (H: Hot; C: Cold; E:
Ground)
50. Input Sensitivity Switch [PHANTOM, GND LIFT, MIC/LINE]
4-pole switch. Enables phantom power (+15V; ON/OFF, enabled only
when set to the MIC position), ground lift and input sensitivity.
Input sensitivity: –36 or –50 dB (MIC mode) / –10 or +4 dB (LINE mode)
ACCESSORY I.T.E 78CK
E
C
H
E
C
H
1
MIC/LINE INPUT MODULE model D-922E
OFF : PHANTOM
LIFT : GND
LINE
-36dB(MIC)
+4dB(LINE)
ON
NORMAL
MIC
-10dB(LINE)
-50dB(MIC)
OFF : PHANTOM
LIFT : GND
LINE
-36dB(MIC)
+4dB(LINE)
ON
NORMAL
MIC
-10dB(LINE)
-50dB(MIC)
2
49
50
5.2.5. D-936R Stereo Input Module
51. Stereo Input Terminal [1L/1R, 2L/2R, 3L/3R, 4L/4R]
Unbalanced, RCA pin jack stereo input terminals. Either a single stereo
input can be selected from the 4 available stereo inputs or all 4 stereo
channels can be mixed.
Mode setting and stereo selection are performed at the front panel
setting screen. They can also be remotely selected by way of connected
external equipment through the use of the control module.
Input signal level: –10 dB
ACCESSORY I.T.E 78CK
1R
2R
1L
2L
3L3R
4L4R
model D-936RSTEREO SELECT INPUT MODULE [ –10 dB]
51
OFF : PHANTOM
LIFT : GND
LINE
-36dB(MIC)
+4dB(LINE)
ON
NORMAL
MIC
-10dB(LINE)
-50dB(MIC)
5.2.6. D-971M Line Output Module
52. Monaural Output Terminal [1, 2, 3, 4] (XLR-3-32 equivalent)
Electronically-balanced output terminal. (Pin 1:
Ground; Pin 2: Hot; Pin 3: Cold)
Output signal level: +4dB
Use XLR-3-11C or equivalent for connection.
ACCESSORY I.T.E 78CK
4
3
2
1
LINE OUTPUT MODULE
[+4 dB]
model D-971M
52
1
2
3
: E
: H
: C
2: Hot
1: Ground
3: Cold

14
5.2.7. D-971E Line Output Module
53. Monaural Output Terminal [1, 2, 3, 4]
Electronically-balanced, removable terminal block. (H: Hot; C: Cold; E:
Ground.)
Output signal level: +4 dB
ACCESSORY I.T.E 78CK
model D-971E
E
C
H
E
C
H
E
C
H
4
3
2
1
LINE OUTPUT MODULE [+4 dB]
E
C
H
53
5.2.8. D-971R Line Output Module
54. Monaural Output Terminal [1(L), 2(R), 3(L), 4(R)]
Unbalanced, RCA pin jack output terminals. Each output is equipped
with a 2-channel splitter.
Output signal level: –10 dB
ACCESSORY I.T.E 78CK
4(R) 3(L)
2(R) 1(L)
model D-971RLINE OUTPUT MODULE [–10 dB]
54
5.2.9. D-981 Remote Control Module
55. Contact Input Terminal [INPUT, C, 1, 2, 3, 4, 5, 6, 7, 8, C]
Removable terminal block, 8-circuit contact input terminal. Individual
contact functions are assigned on the front panel setting screen.
56. Contact Output Terminal [OUTPUT, C, 1, 2, 3, 4, 5, 6, 7, 8, C]
Removable terminal block, 8-circuit contact output terminal. Individual
contact functions are assigned on the front panel setting screen.
ACCESSORY I.T.E 78CK
REMOTE CONTROL MODULE model D-981
C
C
8
C
OUTPUT
INPUT
C
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
55
56

15
6. SETTING BASICS
6.1. Setting Procedures
The D-901's functions need to be set using the front-mounted keys and knob according to scenes of use. After
connecting all external equipment, check the following, then follow the procedures below to set each of the
unit's functions.
Check to be sure that
•The required modules are correctly inserted.
•The power supply is correctly connected.
•The power indicator lights when the power switch is turned on.
Step 1. Set which input channel signal is transmitted to which output channel.
Step 2. Set the input sensitivity.
Step 3. Set the input channel gain.
Step 4. Set the output channel gain.
Step 5. Set individual functions as required.
Because the factory default setting is made so that each input (1 –12) is assigned to all outputs (1
–8) via the Microphone Bus*, when a microphone, or CD player or other music player is
connected to an input, its signals are output from all output terminals by simply increasing the
corresponding input channel gain. Make input-to-output re-assignment according to scenes of use.
* Refer to p. 74, Block Diagram.
(Refer to p. 38, Bus assignment settings.)
This setting can be performed in either of two ways: On the setting screen display or by way of the
front-mounted keys.
When the D-921E or D-921F is installed, perform this setting by displaying the setting screen.
(Refer to p. 24, PAD Settings.)
When the D-922E or D-922F is installed, perform this setting using its DIP switch.
(Refer to p. 12 –13.)
Set the sensitivity so that the front-mounted Input channel indicator [SIG] does not light red.
(Refer to p. 23, Input/Output Gain Settings.)
This setting can be performed in any of three ways: On the setting screen display (two methods)
or by way of the front-mounted keys.
(Refer to p. 23, Input/Output Gain Settings.)
This setting can be performed in any of three ways: On the setting screen display (two methods)
or by way of the front-mounted keys.
(Refer to p. 16, Setting Flowcharts.)
Refer to the setting flowcharts for the appropriate setting method for the function to be used.
When using Stereo Link, Grouping and Crossover functions, first perform the required settings
on the Utility setting screen.

16
Note
It is highly recommended that any changed parameters be immediately saved as preset memory on the
Preset Memory setting screen. (Refer to p. 54, Preset Memory Save.) This permits the parameters of each
function to be saved and protected, even if the power is switched off. All currently saved parameters can be
recalled and reproduced when the power is switch on again. (Refer to p. 55, Initial Preset Memory Selection.)
Settings need not be saved when temporarily setting or changing parameters.
6.2. Setting Flowcharts
All the functions described hereinafter can also be set at a PC using the dedicated software. Please access
our website "http://www.toa-products.com/international/" for its download.
In the following charts, the Screen shift keys [ ] are used to move vertically (next screen display) and the
shift keys [ ] to move horizontally between the solid line setting screen boxes ( ) . For movements
within the dotted line setting screen boxes ( ) and parameter settings for each setting screen, refer to the
corresponding pages.
6.2.1. Input and output settings
Input 1 Gain Settings Input Trim Gain Settings
Cutoff Frequency Settings Q settings
Input trim polarity settings
High-pass filter settings (p. 26)
Input trim settings (p. 25)
Phantom power ON/OFF Settings
(Only when the PAD is set to
"MIC.") (p. 24)
(p. 24)
Line (Stereo) Input Selection
Line Input Mode Selection (p. 24)
PAD (Input Sensitivity) Settings
(Only when using the D-921E or D-921F
Microphone/Line Input Module)
(Only when using the D-936R Stereo
Input Module)
Gain Settings (low frequency) Center frequency settings
Q settings
Equalizer settings (p. 27)
Gain Settings (high frequency) Center frequency settings
Q settings
(To next page) (To next page)
1 2
(p. 25)
Compressor/Auto-Leveler Mode
Selection (p. 28)

17
Input 12 Gain Settings
NOM Attenuation ON/OFF Settings
(p. 36)
Input Channel Group Trim Gain
Settings (p. 37)
Auto-Mixing Group Settings
(p. 34)
Input Channel Gain Settings
(p. 37)
(Only when Group is set)
Priority Settings Attenuation settings
Attack time settings
Release time settings
Ducker settings (p. 35)
Same items as for Input 1
(From the previous page) (From the previous page)
(To next page)
Hysteresis settings
Depth settings
Hold time settings
Attack time settings
Release time settings
Threshold Level Settings
Gate settings (p. 32)
1 2
3
Attack Time Settings Release time settings
Level sense settings (p. 31)
Bus Assignment Settings Crosspoint gain settings
Bus assignment and crosspoint gain settings (p. 38)
Threshold Level Settings
Ratio settings
Attack time settings
Release time settings
Makeup gain settings
(Compressor mode)
Compressor settings (p. 28)
Target Level Settings
Maximum gain settings
Attack time settings
Release time settings
(Auto-leveler mode)
Auto-leveler settings (p. 30)

18
Output 1 Gain Settings
Output 8 Gain Settings
Output Channel Gain Settings
(p. 39)
Output Channel Group Trim Gain
Settings (p. 39)
Delay Time Settings (p. 48)
Slope Settings (High Frequency) Cutoff frequency settings
Q settings
Q2 settings
Crossover gain settings
Crossover filter polarity settings
Slope Settings (Low Frequency) Same items as for high frequency
Crossover settings
(Only when Crossover function is enabled) (p. 40)
Same items as for Output 1
Filter 1 Settings (Type Selection) Parametric equalizer
High-pass filter (6 dB/12 dB)
Low-pass filter (6 dB/12 dB)
High shelving filter
Low shelving filter
Horn equalizer
Notch filter
All-pass filter
Filter 6* Settings (Type Selection) Same items as for Filter 1
Filter settings (p. 42)
Threshold Level Settings Ratio settings
Attack time settings
Release time settings
Makeup gain settings
Compressor settings (p. 47)
(From the previous page)
(Only when Group is set)
3
* The number of filters to be displayed differs depending on crossover configuration settings. (Refer to p. 57.)

19
6.2.2. Microphone bus settings
Auto mode activation
Filter number settings
Dynamic mode filter initialization
Auto mode filter initialization
Feedback suppression settings (p. 49)
Mode Confirmation
(Filter 1 settings)
Mode Confirmation
(Filter 12 settings)
Frequency confirmation
Filter gain confirmation
Q confirmation
Same items as for Filter 1
Feedback suppression filter setting confirmation (p. 51)
Echo Gain Settings Feedback ratio settings
Feedback delay settings
Initial echo (pre-) delay settings
Low-pass filter frequency settings
Low-pass filter Q settings
Effect (echo) settings (p. 52)
SEL
Microphone bus selector key
Effect key
Dynamic Mode Settings
EFFECT
Bus Assignment Settings Crosspoint gain settings
Bus assignment and crosspoint gain settings (p. 53)
6.2.3. Preset memory settings
PRESET
Preset key
Configuration Save (p. 55)
Preset Memory Recall (p. 54)
Preset Memory Delete (p. 55)
Preset Memory Save (p. 54)
Initial Preset Memory Selection
(p. 55)

20
6.2.4. Utility settings
RS-232C transmission rate settings
Control Mode Selection
Preset memory recall
Volume UP
Volume DOWN
Channel ON/OFF
Line (stereo) input selection
Contact input/output settings (p. 60)
(Only when using D-981 Remote Control Module)
RS-232C port settings (p. 65)
Module type confirmation (p. 66)
Operation key protection ON/OFF
UTILITY
Utility key
Protect Settings (p. 63)
Stereo Link Settings (p. 56)
Cooling Fan Operating Status
Confirmation (p. 67)
Gain confirmation for all 12 input channels
Gain confirmation for all 8 output channels
All Input/Output Channel Gain
Confirmation (p. 65)
Firmware Version Confirmation
(p. 67)
Group Settings (p. 56)
NOM Attenuation Settings (p. 59)
Crossover Configuration Settings
(p. 57)
Input Contact Number Selection
Normal make/break
Preset memory recall tally
Channel ON/OFF tally
Contact input status tally
Line (stereo) input selection tally
Output Contact Number Selection
All slots confirmation
Individual Slots Confirmation