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An all-pole mains switch with a contact separation of at least 3 mm (0.12") in each pole
shall be incorporated in the electrical installation of the building.
DUAL POWER AMPLIFIERS
DA-250D CU
DA-250DH CU
Thank you for purchasing TOA's Dual Power Amplifier.
Please carefully follow the instructions in this manual to ensure long, trouble-free use of your equipment.
Note: The figure shows the DA-250D.
OPERATING INSTRUCTIONS
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TABLE OF CONTENTS
1. IMPORTANT SAFETY INSTRUCTIONS .................................................... 3
2. SAFETY PRECAUTIONS ............................................................................... 5
3. GENERAL DESCRIPTION ............................................................................. 9
4. FEATURES .......................................................................................................... 9
5. HANDLING PRECAUTIONS .......................................................................... 9
6. INSTALLATION PRECAUTIONS ................................................................ 10
7. NOMENCLATURE AND FUNCTIONS
Front ........................................................................................................................ 11
Rear .......................................................................................................................... 12
8. SETTINGS AND CONNECTIONS ............................................................... 13
8.1. Switch Settings and Speaker Connections ...................................................... 14
9. REMOVABLE TERMINAL PLUG CONNECTION .................................. 15
10. INPUT SENSITIVITY AND
HIGH-PASS FILTER ON/OFF SETTINGS
................................................ 16
11. PROTECTION OPERATION LIST ............................................................... 17
12. TAMPER-PROOF CAP ATTACHMENT .................................................... 17
13. CLEANING THE FILTER ................................................................................ 18
14. BLOCK DIAGRAMS
14.1. DA-250D .......................................................................................................... 19
14.2. DA-250DH ........................................................................................................ 19
15. DIMENSIONAL DIAGRAM ............................................................................ 20
16. SPECIFICATIONS
16.1. DA-250D CU .................................................................................................... 21
16.2. DA-250DH CU ................................................................................................. 22
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1. IMPORTANT SAFETY INSTRUCTIONS
• Read these instructions.
• Keep these instructions.
• Heed all warnings.
• Follow all instructions.
• Do not use this apparatus near water.
• Clean only with dry cloth.
• Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
• Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including
amplifiers) that produce heat.
• Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades
with one wider than the other. A grounding type plug has two blades and a third grounding prong. The wide
blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult
an electrician for replacement of the obsolete outlet.
• Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and
the point where they exit from the apparatus.
• Only use attachments/accessories specified by the manufacturer.
• Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer,
or sold with the apparatus. When a cart is used, use caution when moving the
cart/apparatus combination to avoid injury from tip-over.
• Unplug this apparatus during lightning storms or when unused for long periods of time.
• Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been
damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have
fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or
has been dropped.
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INSTRUCTIONS ESSENTIELLES POUR LA SÉCURITÉ
• Lire ces instructions.
• Conserver ces instructions pour référence ultérieure.
• Respecter tous les avertissements.
• Suivre toutes les instructions.
• Ne pas utiliser cet appareil à proximité d'eau.
• Nettoyer uniquement à l'aide d'un chiffon sec.
• Ne pas obstruer les orifices de ventilation. Installer conformément aux instructions du fabricant.
• Ne pas installer à proximité de sources de chaleur telles que des radiateurs, des registres thermiques, des
chaudières ou d'autres appareils (notamment des amplificateurs) produisant de la chaleur.
• Ne pas contourner la fonction de sécurité de la fiche polarisée ou de mise à la terre. Une fiche polarisée est
équipée de deux broches, dont l'une est plus large que l'autre. Une fiche de mise à la terre est équipée de
deux broches et d'une troisième pour la mise à la terre. Cette dernière, la plus large, est prévue à des fins
de sécurité. Si la fiche fournie ne peut être insérée dans la prise électrique souhaitée, consulter un
électricien pour faire remplacer cette dernière.
• Protéger le cordon d'alimentation pour éviter qu'il ne soit piétiné ou pincé, notamment au niveau des fiches,
des prises de courant ou de son point de sortie de l'appareil.
• Utiliser uniquement les accessoires spécifiés par le fabricant.
• Utiliser uniquement avec le chariot, support, trépied, la patte de montage ou la table
spécifiés par le fabricant ou vendus avec l'appareil. En cas d'utilisation d'un chariot,
manipuler la combinaison chariot/appareil pour éviter les blessures dues à un
renversement.
• Débrancher cet appareil pendant les orages ainsi que lorsqu'il reste inutilisé pendant une période prolongée.
• La maintenance de l'appareil doit être confiée à un technicien après-vente qualifié. Une maintenance s'avère
nécessaire si l'appareil est endommagé (au niveau du cordon d'alimentation ou de la fiche), a été mouillé
par un liquide, un objet est tombé à l'intérieur, s'il a été exposé à la pluie ou l'humidité, s'il ne fonctionne pas
normalement ou s'il est tombé.
Note: This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the instruction manual, may cause harmful interference to
radio communications. Operation of this equipment in a residential area is likely to cause harmful
interference in which case the user will be required to correct the interference at his own expense.
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
• Consult the dealer or an experienced radio/TV technician for help.
FCC REQUIREMENTS
• This Class A digital apparatus complies with Canadian ICES-003.
• Cet appareil numérique de la classe A est conforme à la norme NMB-003 du Canada.
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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.
• Be sure to replace the unit's terminal cover after
connection completion. Because the voltage of up
to 140 V is applied to the high impedance speaker
terminals, never touch these terminals to avoid
electric shock. (DA-250DH only)
• External wiring connected to the terminals marked
with requires installation by an instructed person.
(DA-250DH only)
• The apparatus shall be connected to a mains
socket outlet with a protective earthing connection.
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 such
as modification inside the unit to qualified service
personnel.
• 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.
• Do not insert nor drop metallic objects or flammable
materials in the ventilation slots of the unit's cover,
as this may result in fire or electric shock.
• Do not touch a plug during thunder and lightning,
as this may result in 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.
2. 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 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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• 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 fire or
electric shock. When removing the power cord, be
sure to hold its plug to pull.
• 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.
• To avoid electric shocks, be sure to switch off the
unit's power when connecting speakers.
• The unit is designed exclusively to be mounted in
an equipment rack. Be sure to follow the
instructions below when rack-mounting the unit.
Failure to do so may cause a fire or personal injury.
· Install the equipment rack on a stable, hard floor.
Fix it with anchor bolts or take other arrangements
to prevent it from falling down.
· Be sure to use the screws with a diameter of over
5 mm (0.2") and length of over 12 mm (0.47") to
mount the unit.
· When connecting the unit's power cord to an AC
outlet, use the AC outlet with current capacity
allowable to the unit.
When the Unit is in Use
• With the High-pass filter jumper socket kept to the
OFF position (factory preset), operating the unit for
long periods of time while the Peak indicator is
illuminated due to excessive input signal may
damage the connected speakers, possibly resulting
in fire. Operating the unit with the High-pass filter
jumper socket set to the ON position may decrease
the possibility of speaker damage or fire due to
excessive input signal.
• Make sure to set all input level controls to ∞(infinity)
position before power is switched on.
Loud noise produced when power is switched on
with any of those controls set to the position other
than ∞position 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 fire.
• Contact your TOA dealer as to the cleaning. If dust
is allowed to accumulate in the unit over a long
period of time, a fire or damage to the unit may
result.
• If dust accumulates on the power supply plug or in
the wall AC outlet, a fire may result. Clean it
periodically. In addition, insert the plug in the wall
outlet securely.
• Turn off this unit's power switch, 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.
The lighting flash with arrowhead symbol,
within an equilateral triangle, is intended
to alert the user to the presence of
uninsulated "dangerous voltage" within
the product's enclosure that may be of
sufficient magnitude to constitute a risk of
electric shock to persons.
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CONSEILS DE SÉCURITÉ
• Avant l'installation ou l'utilisation, lire attentivement l'ensemble des instructions de cette section pour un
fonctionnement correct et sûr.
• Veiller à respecter les précautions recommandées dans cette section, laquelle contient des mises en garde
et/ou précautions importantes en matière de sécurité.
• Après lecture, conserver ce manuel à portée de main pour consultation ultérieure.
Symboles de sécurité et conventions
Les symboles et messages de sécurité décrits ci-dessous sont utilisés dans cette notice pour prévenir tout
dommage corporel ou matériel pouvant résulter d'une mauvaise utilisation. Lire attentivement cette notice
pour comprendre parfaitement les symboles et messages de sécurité afin de prévenir tout risque éventuel.
Indique une situation risquant d'entraîner des blessures
graves, voire la mort, en cas de mauvaise manipulation.
Indique une situation risquant d'entraîner des blessures
moyennement graves ou mineures, et/ou des dommages matériels.
AVERTISSEMENT
ATTENTION
Lors de l'installation de l'appareil
• Ne pas exposer l'appareil à la pluie et le protéger
de tout contact avec de l'eau ou d'autres liquides
afin d'éviter un incendie ou une électrocution.
• Utilisez l'appareil uniquement avec la tension
spécifiée sur le chargeur. L'utilisation d'une tension
supérieure à celle spécifiée peut être à l'origine
d'un incendie ou d'une électrocution.
• Ne pas couper, entortiller, modifier ou
endommager le cordon d'alimentation. En outre,
éviter d'utiliser le cordon d'alimentation à proximité
d'un radiateur et ne jamais placer d'objets lourds (y
compris l'appareil lui-même) sur le cordon
d'alimentation, car ceci présente un risque
d'incendie ou d'électrocution.
• Veiller à remettre en place le capot de l'appareil
une fois les connexions réalisées.
Les bornes du haut-parleur à haute impédance
étant soumis à une tension jusqu'à 140 V, ne
jamais toucher ces bornes pour éviter un risque de
choc électrique.
(DA-250DH uniquement)
• Les câbles externes branchés aux bornes
marquées de doivent être installé par un
technicien spécialement formé.
(DA-250DH
uniquement)
• L'appareil doit être branché à une prise
d'alimentation avec mise à la terre de protection.
Pendant l'utilisation de l'appareil
• En cas de survenue des irrégularités suivantes
pendant l'utilisation, couper immédiatement
l'alimentation, débrancher la fiche du cordon
d'alimentation de l'adaptateur secteur de la prise
secteur et contacter le représentant TOA le plus
proche. Ne pas essayer pas d'utiliser l'appareil
dans ces conditions sous peine de provoquer un
incendie ou une électrocution.
· Détection de fumée ou d'une odeur inhabituelle
émanant de l'appareil.
· Pénétration d'eau ou d'un objet métallique dans
l'appareil
· Chute ou endommagement de l'appareil
· Dégradation du cordon d'alimentation (âme du
câble dénudée, déconnexion etc.).
· Dysfonctionnement (absence de tonalité).
• Pour empêcher un incendie ou une électrocution,
ne jamais ouvrir ni ne retirer le boîtier de l'appareil,
en raison de la préswence de pièces à haute
tension. Toutes les opérations de maintenance,
notamment les modifications apportées à l'intérieur
de la machine, doivent être réalisées par un
technicien qualifié.
• Ne pas placer de tasses, bols ou autres récipients
remplis de liquides ou d'objets métalliques audessus de l'appareil. S'ils se répandent par
accident sur l'appareil, ils peuvent provoquer un
incendie ou une électrocution.
• Ne pas insérer ni laisser tomber d'objets
métalliques ou de matériaux inflammables dans les
évents de ventilation du capot de l'appareil sous
peine de provoquer un incendie ou une
électrocution.
• Ne pas toucher la fiche du cordon d'alimentation
pendant un orage - Risque d'électrocution.
AVERTISSEMENT
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L'éclair accompagné d'un symbole
représentant une pointe de flèche à
l'intérieur d'un triangle équilatéral avertit
l'utilisateur de la présence d'une "tension
dangereuse" à l'intérieur de l'enceinte du
téléviseur, dont la magnitude peut être
suffisante pour constituer un risque de
choc électrique pour les personnes.
ATTENTION
Lors de l'installation de l'appareil
• Ne jamais brancher, ni débrancher la fiche du
cordon d'alimentation avec les mains mouillées.
Risque d'électrocution.
• Pour débrancher le cordon d'alimentation, veiller à
le tenir par sa fiche ; ne jamais tirer directement le
cordon. Utiliser l'appareil avec un cordon
d'alimentation endommagé peut présenter un
risque d'incendie ou d'électrocution.
• Lors du déplacement de l'appareil, veiller à retirer
la fiche du cordon d'alimentation de l'adaptateur
secteur de la prise murale. Si le chargeur est
déplacé avec le cordon d'alimentation branché
dans la prise, ce dernier risque d'être endommagé,
ce qui présente un risque d'incendie ou
d'électrocution. Pour retirer le cordon
d'alimentation, le tirer par la prise.
• Éviter d'installer l'appareil dans un endroit humide
ou poussiéreux, en plein soleil, à proximité d'un
radiateur, ou dans un endroit dégageant de la
fumée noire ou de la vapeur sous peine de
provoquer un incendie ou une électrocution.
• Pour éviter les chocs électriques, veiller à
débrancher l'appareil avant de connecter les hautparleurs.
• Cet appareil doit uniquement être monté dans un
bâti. Veiller à suivre les instructions ci-dessous lors
du montage en bâti.
Risque d'incendie ou de blessure corporelle.
· Installer le bâti sur un sol stable.
Le fixer à l'aide de boulons d'ancrage ou d'un
autre dispositif pour l'empêcher de tomber.
· Lors du montage de l'appareil, veiller à utiliser
une vis de plus de 5mm (0,2") de diamètre et de
plus de 12mm (0,47") de longueur.
· Pour brancher le cordon d'alimentation à une
prise CA, vérifier l'intensité maximale de
l'appareil.
Pendant l'utilisation de l'appareil
• Lorsque la prise du câble de liaison du filtre passehaut est en position OFF (réglage d'usine),
l'utilisation de l'appareil pendant une période
prolongée lorsque l'indicateur Peak est allumé en
raison d'un signal d'entrée trop fort peut
endommager les haut-parleurs connectés et
potentiellement déclencher un incendie. L'utilisation
de l'appareil avec la prise du filtre passe-haut est
en position ON permet de réduire le risque de
détérioration du haut-parleur ou d'incendie en
raison d'un signal d'entrée trop fort.
• Mettre toutes les commandes du niveau d'entrée en
position ∞ (infini) avant que l'alimentation ne soit
restituée.
Si l'appareil est mis sous tension alors que ces
commandes ne sont pas en position ∞, un bruit fort
au point de dégrader l'audition risque d'être émis.
• Ne pas utiliser l'appareil pendant une période
prolongée si le son est distordu.
Les haut-parleurs branchés risquent de surchauffer
et de provoquer un incendie.
• Pour nettoyer l'appareil, contacter votre revendeur
TOA. L'accumulation de poussière pendant une
période prolongée peut entraîner un incendie ou
une dégradation de l'appareil.
• L'accumulation de poussière sur la fiche du cordon
d'alimentation ou dans la prise secteur présente un
risque d'incendie. Les nettoyer régulièrement.
Par ailleurs, insérer complètement la fiche dans la
prise murale.
• Par mesure de sécurité, lors du nettoyage ou
lorsque l'appareil n'est pas utilisé pendant 10 jours
ou plus, couper l'alimentation, et débrancher la
fiche du cordon d'alimentation de l'adaptateur
secteur de la prise secteur - Risque d'incendie ou
d'électrocution.
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3. GENERAL DESCRIPTION
TOA's DA-250D and DA-250DH Dual Power Amplifiers feature high power handling capabilities and durability.
The DA-250D is configured with 250 W x 2 channels (4 Ω output) and 170 W x 2 channels (8 Ω output), and
the DA-250DH features a 250 W x 2 channels (70 V line, 19.6 Ω output) configuration.
Besides, each model's output is made available for bridge connection, allowing it to be used as a monaural
amplifier of 500 W (8 Ω for DA-250D, 140 V line 39.2 Ω for DA-250DH).
Their wide range of applications include stores and permanent sound systems.
4. FEATURES
• 1U rack mounting size*.
• Low power consumption and light weight.
• An input signal to Channel 1 can be routed to both channels 1 and 2, and the output level adjusted using the
input level control for each channel.
• Electronically-balanced inputs.
• Input terminals employ removable terminal blocks and XLR type connectors to provide maximum connection
ease.
• Equipped with the LED indicators that show the input/output status, etc.
• Built-in protection circuitry disconnects the power amplifier's output from the load when a short circuit,
overload, or unusual temperature rise occurs.
* 1U size = 44.5 mm or 1.75" (reference size)
5. HANDLING PRECAUTIONS
• Keep the input cable away from the output cable. If installed close to each other, oscillation could occur.
• To avoid unit failures, never connect outputs of two or more channels in parallel.
• Only connect speakers with an impedance equal to or greater than those specified. Connecting speakers
with a smaller impedance than specified could cause damage to the unit.
• Periodically clean the filter located inside the ventilation panel on the unit's front panel. If the filter becomes
clogged, heat will become trapped inside the enclosure.
• Install the unit in locations where the temperature is between –10 and +40°C (14°F and 104°F) and the
moisture is less than 90%RH (no dew condensation must be formed).
• To clean, be sure to first turn off this unit's power switch, then wipe with a dry cloth. When the unit gets very
dirty, use a cloth damped in a neutral cleanser. Never use benzene, thinner, alcohol, or chemically-treated
cleaning cloth because such volatile liquids could deform or discolor the unit.
• The fan is a consumable product. As a guideline, we recommend that it be replaced with a new one when its
total operating time reaches approximately 20000 hours (when used in ambient temperatures of
approximately 25°C or 77°F).
Note: The above figure is simply a guideline, and does not guarantee the fan’s operating life. Since
broadcasts from the digital power amplifier could be disabled if the fan malfunctions, the fan requires
regular inspection and maintenance. For maintenance service, please contact the dealer from whom
the digital amplifier was purchased.
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Rack mounting screws are not supplied with the unit.
Be sure to use the screws with a diameter of over 5 mm (0.2") and
length of over 12 mm (0.47") to mount the unit.
Failure to do so may cause personal injury.
CAUTION
6. INSTALLATION PRECAUTIONS
• The supplied power supply cord is designed for exclusive use with this unit. Never use it with other
equipment.
• When mounting the unit in an equipment rack, the inside of the rack must be sufficiently ventilated.
To achieve sufficient ventilation, remove all panels on the rear of the rack.
• When mounting the unit in the rack, also mount a Perforated Panel larger than 1U in size*:
(1) at the top and the bottom of the rack, and
(2) above and below every 5 units.
• Robust structure is one of the unit's main features. However, if the strength is particularly needed when
installing the unit in the rack, use a supporting runner for the safety purposes.
* 1U size = 44.5 mm or 1.75" (reference size)
Power amplifiers
(5 units)
Power amplifiers
(5 units)
Perforated panel
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1. Power switch [ ON / OFF]
Turning this switch on causes the amplifier to
function, and turning it off causes the amplifier to
cease function.
Note
The unit is not completely disconnected from the
power supply even if this Power switch is turned
off.
2. Power indicator [POWER]
Lights blue when the Power switch (1) is turned
on.
3. Input level controls [CH 1/BRIDGE, CH 2]
Adjust the input level of each channel.
Turn the control clockwise to increase the input
level and counterclockwise to decrease the level.
4. Ventilation panel (Air Vent)
A filter is located inside the ventilation panel.
To clean the filter, remove the ventilation panel.
(See p. 18; Cleaning the Filter.)
5. Indicators [INPUT, OUTPUT, PEAK, PROTECT]
The indicators are as follows from left to right:
• Input indicator [INPUT]
Lights green regardless of the input level
control setting when an input signal level
exceeds about –20 dB.
• Output indicator [OUTPUT]
Lights yellow when an output level exceeds
about 1 W at an 8 Ω load (DA-250D) or 19.6 Ω
load (DA-250DH).
• Peak indicator [PEAK]
Lights red when an output signal clips
(distortion occurs).
Note
When the Peak indicator lights, turn the input
level control (3) counterclockwise until its light
extinguishes or decrease the input signal level
of the connected external device.
Operating the unit while the Peak indicator
remains lit may cause the protection circuitry to
be activated.
• Protection indicator [PROTECT]
Lights red when the protection circuitry is
activated. (See p. 17; Protection Operation
List.) When the power is switched on, this
indicator lights for about 2 seconds and then
extinguishes.
When a bridge connection is made
When Channels 1 and 2 are bridge-connected
(BRIDGE ON/OFF switch (9) is set to ON), the
CH 1/BRIDGE level control adjusts the input
levels of Channels 1 and 2. In this event, the
CH 2 level control cannot be used.
7. NOMENCLATURE AND FUNCTIONS
[Front]
1243 5
Note: The figure shows the DA-250D.
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[Rear]
6. AC inlet
Connect the supplied power cord to this inlet.
The socket-outlet shall be installed near the
equipment and the plug (disconnecting device)
shall be easily accessible.
7. Functional ground terminal [SIGNAL GND]
Hum noise may be generated when external
equipment is connected to the unit. Connecting
this terminal to the functional ground terminal of
the external equipment may reduce the hum
noise.
Note
This terminal is not for protective ground.
8.
Speaker output terminals (with a terminal cover)
Connect speaker cables to these terminals.
9. BRIDGE ON/OFF switch
[BRIDGE, ON / OFF]
Used when bridge-connecting the unit's Channels
1 and 2.
(See p. 13; Settings and Connections.)
• 2-channel output mode
Set BRIDGE switch to OFF. (factory-preset)
• 1-channel output mode
Set BRIDGE switch to ON.
Note
Be
sure to first turn off the Power switch (1) when
changing these switch settings.
10. CH1 mode ON/OFF switch
[PARALLEL, ON / OFF]
Setting this switch to ON transmits the Channel 1
input signal to both channels 1 and 2. (PARALLEL
mode)
Note that output signal levels can be individually
adjusted with each channel's Input level control
(3).
Setting this switch to OFF (factory-preset)
transmits each channel's input signal to each
corresponding channel. (STEREO mode)
Note
Be
sure to first turn off the Power switch (1) when
changing this switch setting.
11. Input terminals [INPUTS]
Electronically-balanced input terminals.
Each removable terminal block (3 pins) is
internally connected in parallel to the
corresponding XLR type connector.
• Removable terminal block (3 pins)
H: Hot, C: Cold, E: Earth
•
XLR type male connector (XLR-3-31 equivalent)
Pin 1: Earth, Pin 2: Hot, Pin 3: Cold
If a straight plug hits the rack's rear cover or
wall behind the rack when it is used for
connection, use the L-shaped plug instead.
Caution when using an XLR type plug
DA-250D
DA-250DH
6
7 9 10
6
7 9 10
8
8
11
11
Page 13
13
Step 1. Turn off this unit's Power switch.
Step 2. Set the BRIDGE ON/OFF switch and CH 1 mode ON/OFF switch.
Step 3. Connect the sound source equipment to the Input terminals.
Note: Refer to p. 15 for the removable terminal plug connection.
Step 4. Connect speakers to the Speaker output terminals.
4-1. Unscrew the output terminal cover.
4-2. Strip 10 mm (0.39") of insulative jacket from the end of the speaker cable,
as shown in the figure at right.
4-3. Connect speaker cables to the output terminals.
4-4. Replace the output terminal cover in place.
Be sure to replace the unit's terminal cover after connection completion.
Because high voltage is generated at the speaker output terminals,
never touch these terminals to avoid electric shock.
(DA-250DH only)
WARNING
8. SETTINGS AND CONNECTIONS
[Rear panel]
CH 1 mode ON/OFF switchBRIDGE ON/OFF switch
Speaker output terminals
(with a terminal cover)
Input terminals
Note: The figure shows the DA-250D.
10 mm
(0.39”)
Page 14
14
8.1. Switch Settings and Speaker Connections
[2 inputs - 2 outputs] (factory-preset)
CH1
CH2
CH1
CH2
Switch
BRIDGE
CH 1 mode
Setting
OFF
OFF
Speaker output terminals
CH2 CH1
DA-250D DA-250DH
4 – 8 Ω
19.6 Ω
[1 input - 2 outputs]
CH1
CH1
CH2
[1 input - 1 output]
CH1
CH1
CH2
Switch
BRIDGE
CH 1 mode
Switch
BRIDGE ON
Setting
OFF
ON
Setting
Speaker output terminals
CH2 CH1
Speaker output terminals
BRIDGE
4 – 8 Ω
DA-250D DA-250DH
4 – 8 Ω
4 – 8 Ω
DA-250D DA-250DH
19.6 Ω
19.6 Ω
19.6 Ω
Note
Channel 1 input signal is output regardless
of the CH1 mode ON/OFF switch setting.
8 Ω 39.2 Ω
Page 15
15
Cable end treatment
Connector connections
Step 1. Loosen the terminal screw, then insert the cable.
Step 2. Retighten the terminal screw. (Pull on the cable to ensure it is securely connected.)
Tip
Recommended slotted screwdriver type: Screwdriver with blade that is 3 mm (0.12") in width
Cautions
• Be sure to use shielded cables for audio signal lines.
• Avoid soldering cable conductor, as contact resistance may increase when the cable is tightened and the
solder is crushed, possibly resulting in an excessive rise in joint temperatures.
• Use cables of AWG 12 – 24.
9. REMOVABLE TERMINAL PLUG CONNECTION
Shielded cable
7 mm
(0.28”)
20 mm
(0.79”)
Tightens Loosens
2
Slotted screwdriver
1
Terminal screw
1
Hot
Earth
Cold
Shielded cable
Bit shape 3 mm (0.12”)
Removable terminal
plug
Page 16
16
The Input sensitivity can be set to +4 dB (factory-preset) or -10 dB for each channel.
Besides, only the DA-250DH employs the High-pass filter on each channel, which can be set to "ON" or "OFF."
Step 1. Remove this unit's power plug from an AC outlet.
Step 2. Unscrew 7 screws securing the top cover of the unit, then detach it.
Step 3. Change the jumper socket position to "+4 dB" or "–10 dB" for the Input sensitivity as illustrated below.
When a bridge connection is made;
Set the input sensitivity with the CH1 jumper socket when Channels 1 and 2 are bridge-connected.
(Input sensitivity setting for the CH2 is disabled.)
Step 4. Change the jumper socket position to "ON" or "OFF" for the High-pass filter as illustrated above.
(DA-250DH only)
ON position: High-pass filter ON (–12 dB/oct, cut off frequency 50 Hz)
OFF position: High-pass filter OFF
Step 5. Replace the detached top cover.
With the High-pass filter jumper socket kept to the OFF position (factory preset), operating the
unit for long periods of time while the Peak indicator is illuminated due to excessive input signal
may damage the connected speakers, possibly resulting in fire.
Operating the unit with the High-pass filter jumper socket set to the ON position may decrease
the possibility of speaker damage or fire due to excessive input signal.
CAUTION
These servicing instructions are for use by qualified personnel only. To avoid electric shock, do not
perform any servicing other than that contained in the operating instructions unless you are qualified to
do so. Refer all servicing to qualified service personnel.
CAUTION
When a bridge connection is made;
Perform the same setting for both Channels 1 and 2.
Operating the unit with the different setting may cause unit failure.
10. INPUT SENSITIVITY AND HIGH-PASS FILTER ON/OFF SETTINGS
Input sensitivity setting
[When set to +4 dB]
(Factory-preset)
Jumper socket
10 dB/+4 dB
-
[When set to –10 dB]
Jumper socket
Input Sensitivity
10 dB/+4 dB
-
Input Sensitivity
2
Viewed from top with the
top cover detached.
CH1 CH2
Front panel
3
High-pass filter setting (DA-250DH only)
[When set to OFF]
(Factory-preset)
ON/OFF
Jumper socket
Hi Pass
[When set to ON]
Filter
Jumper socket
ON/OFF
Hi Pass
Filter
Page 17
17
11. PROTECTION OPERATION LIST
12. TAMPER-PROOF CAP ATTACHMENT
To protect the input level control from accidental operation, it is recommended to replace the control knob with
the supplied tamper-proof cap as illustrated.
Failure Protection Operation Indicator Remedy Recovery
Overcurrent due
to overload
Short circuit Current limiter activated.
Temperature rise
at power amp.
heat sink
(over 100°C or 212°F)
Temperature rise
inside the unit
(over 80°C or 176°F)
Abnormal DC
voltage output
Current limiter activated
when impedance drops
below the specified
value.
Load is disconnected.
Load disconnected. Protection indicator
Built-in amplifier unit
that caused the failure
halted.
Load disconnected. Protection indicator
Peak indicator lights. Remove overload. Connecting a correct load
Protection indicator
lights.
lights.
Four indicators of
the corresponding
channel extinguish.
lights.
automatically restores
normal operation.
Check speakers
and lines for short
circuit.
Check the unit for
correct ventilation
and overload.
Contact the TOA dealer where the unit was
purchased.
Turn off this unit's Power
switch. Correct the load,
then turn on the power.
Operation automatically
returns to normal when
the temperature decreases.
Input level control
Tamper-proof cap (accessory)
Page 18
18
13. CLEANING THE FILTER
Step 1. Turn off this unit's Power switch.
Step 2. Remove the ventilation panel as shown in the figure.
Step 3. Detach the filter inside the ventilation panel.
Step 4. Clear the filter of dust.
Step 5. Replace the filter and ventilation panel.
Ventilation Panel
Filter
3
2
Detach the panel by pressing on the left or right side.
Ventilation Panel
Page 19
19
T
14. BLOCK DIAGRAMS
14.1. DA-250D
14.2. DA-250DH
T
CH 1 INPUT
H
C
E
HE
C
CH 2 INPUT
H
C
E
HE
C
PARALLEL
switch
CH 1 INPUT
H
C
E
HE
C
CH 2 INPUT
H
C
E
HE
C
PARALLEL
switch
CH 1
input level
control
CH 2
input level
control
CH 1
input level
control
CH 2
input level
control
CH 1 sensitivity
selection jumper
(+4 dB/
CH 2 sensitivity
selection jumper
(+4 dB/
+4 dB
-
CH 1 sensitivity
selection jumper
-
10 dB)
(+4 dB/
+4 dB
-
CH 2 sensitivity
selection jumper
-
10 dB)
(+4 dB/
-
10 dB)
-
10 dB)
10 dB
10 dB
+4 dB
-
10 dB
+4 dB
-
10 dB
BRIDGE ON/OFF
switch
ON
OFF
BRIDGE ON/OFF switch
HPF
50 Hz
CH 1 HPF
ON/OFF jumper
ON
OFF
HPF
50 Hz
CH 2 HPF
ON/OFF jumper
Current Limiter
Short Detector
Protection Circuit
Current Limiter
Short Detector
Protection Circuit
OFF
ON
OFF
ON
OUTPUT 1
OUTPUT 2
Current Limiter
Short Detector
Protection Circuit
Current Limiter
Short Detector
Protection Circuit
relay
relay
OUTPUT 1
relay
OUTPUT 2
relay
CH 1
OUTPUT
+
-
+
-
CH 2
OUTPUT
CH 1
OUTPUT
+
-
+
-
CH 2
OUTPUT
BRIDGE
OUTPU
BRIDGE
OUTPU
Page 20
20
15. DIMENSIONAL DIAGRAM
Unit: mm (inches)
442 (17.4)
(0.89)
371 (14.61) 22.5
401.8 (15.82)
465 (18.31)
482 (18.98)
31.8
44
(1.25)
(1.73)
Page 21
21
* 0 dB = 0.775 V
Note: The design and specifications are subject to change without notice for improvement.
Power cord (2 m or 6.56 ft) .................................................. 1
Removable terminal plug (3 pins) ........................................ 2
Tamper-proof cap ................................................................ 2
• Accessories
120 V AC, 50/60 Hz
Class D
120 W (based on UL/CSA standards)
650 W (rated output 4 Ω x 2)
420 W (rated output 8 Ω x 2)
2 circuits, +4 dB* (1.23 V, input level control in maximum position),
10 kΩ, electronically-balanced, removable terminal block (3 pins),
XLR-3-31 type connector
CH 1 mode ON/OFF switch (ON: PARALLEL, OFF: STEREO)
2 channels: 250 W x 2 (4 Ω), 170 W x 2 (8 Ω)
1 channel (BRIDGE): 500 W (8 Ω)
M4 screw terminal, distance between barriers: 8.8 mm (0.35")
20 – 20,000 Hz (±1 dB)
0.1% (1 kHz), 0.3% (20 – 20,000 Hz)
Protection against excessive current flow due to overload,
short circuit, unusual DC voltage output,
temperature rise at power amp. heat sink (over 100°C or 212°F),
temperature rise inside the unit (over 80°C or 176°F)
100 dB (A-weighted)
70 dB (A-weighted)
Power (blue) x 1, Input (green) x 2, Output (yellow) x 2, Peak (red) x 2,
Protect (red) x 2
Forced air cooling
–10°C to +40°C (14°F to 104°F)
Under 90% RH (no condensation)
Panel: Aluminum, black, alumite
Case: Plated steel sheet
482. (w) x 44 (h) x 401.8 (d) mm (18.98" x 1.73" x 15.82")
5 kg (11.02 lb)
Power Source
Amplification system
Power Consumption
Input
Rated Output
Frequency Response
Total Harmonic Distortion
Protection Circuit
S/N Ratio
Crosstalk
LED Indicator
Cooling
Operating Temperature
Operating Humidity
Finish
Dimensions
Weight
16.1. DA-250D CU
16. SPECIFICATIONS
Page 22
22
* 0 dB = 0.775 V
Note: The design and specifications are subject to change without notice for improvement.
Power cord (2 m or 6.56 ft) .................................................. 1
Removable terminal plug (3 pins) ........................................ 2
Tamper-proof cap ................................................................ 2
• Accessories
120 V AC, 50/60 Hz
Class D
120 W (based on UL/CSA standards)
580 W (rated output 70 V line, 19.6 Ω x 2)
2 circuits, +4 dB* (1.23 V, input level control in maximum position),
10 kΩ, electronically-balanced, removable terminal block (3 pins),
XLR-3-31 type connector
CH 1 mode ON/OFF switch (ON: PARALLEL, OFF: STEREO)
2 channels: 250 W x 2 (70 V line, 19.6 Ω)
1 channel (BRIDGE): 500 W (140 V line, 39.2 Ω)
M4 screw terminal, distance between barriers: 8.8 mm (0.35")
20 – 20,000 Hz (±1 dB): HPF OFF
50 – 20,000 Hz (–3 dB, +1 dB): HPF ON
(selectable with the inner jumper)
0.1% (1 kHz), 0.3% (20 – 20,000 Hz): HPF OFF
0.1% (1 kHz), 0.3% (100 – 20,000 Hz): HPF ON
Protection against excessive current flow due to overload,
short circuit, unusual DC voltage output,
temperature rise at power amp. heat sink (over 100°C or 212°F),
temperature rise inside the unit (over 80°C or 176°F)
100 dB (A-weighted)
70 dB (A-weighted)
Power (blue) x 1, Input (green) x 2, Output (yellow) x 2, Peak (red) x 2,
Protect (red) x 2
Forced air cooling
–10°C to +40°C (14°F to 104°F)
Under 90% RH (no condensation)
Panel: Aluminum, black, alumite
Case: Plated steel sheet
482. (w) x 44 (h) x 401.8 (d) mm (18.98" x 1.73" x 15.82")
5 kg (11.02 lb)
Power Source
Amplification system
Power Consumption
Input
Rated Output
Frequency Response
Total Harmonic Distortion
Protection Circuit
S/N Ratio
Crosstalk
LED Indicator
Cooling
Operating Temperature
Operating Humidity
Finish
Dimensions
Weight
16.2. DA-250DH CU
Page 23
Page 24
133-02-00053-00
URL: http://www.toa.jp/
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