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OPERATING INSTRUCTIONS
MULTICHANNEL POWER AMPLIFIERS
DA-250F CU
DA-250FH CU
Note: The figure shows the DA-250F.
Thank you for purchasing TOA's Multichannel Power Amplifier.
Please carefully follow the instructions in this manual to ensure long, trouble-free use of your equipment.
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TABLE OF CONTENTS 1. IMPORTANT SAFETY INSTRUCTIONS .................................................... 3 2. SAFETY PRECAUTIONS ............................................................................... 4 3. GENERAL DESCRIPTION ............................................................................. 6 4. FEATURES .......................................................................................................... 6 5. HANDLING PRECAUTIONS ..........................................
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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
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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
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shock. When the Unit is in Use • When moving the unit, be sure to remove its power • Make sure that all volume controls are set to supply cord from the wall outlet. Moving the unit minimum position before power is switched on. with the power cord connected to the outlet may Loud noise produced at high volume when power is cause damage to the power cord, resulting in fire or switched on can impair hearing. electric shock. When removing the power cord, be sure to hold its plug to pull. • Do not
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3. GENERAL DESCRIPTION TOA's DA-250F and DA-250FH Multichannel Power Amplifiers feature high power handling capabilities and durability. The DA-250F is configured with 250 W x 4 channels (4 Ω output) and 170 W x 4 channels (8 Ω output), and the DA-250FH features a 250 W x 4 channels (19.6 Ω output) configuration. Besides, each model's output is made available for bridge connection, allowing it to be used as a stereo amplifier of 500 W (8 Ω for DA-250F, 39.2 Ω for DA-250FH) x 2 channels or a 3-c
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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.
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7. NOMENCLATURE AND FUNCTIONS [Front] 3 4 5 2 1 Note: The figure shows the DA-250F. 4. Ventilation panel (Air Vent) 1. Power switch [ ON/ OFF] A filter is located inside the ventilation panel. Power is switched on and off with each To clean the filter, remove the ventilation panel. depression of this switch. (See p. 15; Cleaning the Filter.) 2. Power indicator [POWER] 5. Indicators [INPUT, OUTPUT, PEAK, PROTECT] Lights blue when the power is switched on. The indicators are as follows from le
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[Rear] 6 7 8 9 10 9 11 Note: The figure is common to DA-250F and DA-250FH. 6. AC inlet • 3-channel input mode Connect the supplied power cord to this inlet. Set either BRIDGE1 or 2 to ON. When bridge-connecting Channels 1 and 2, set 7. Functional ground terminal [SIGNAL GND] BRIDGE1 to ON, and BRIDGE 2 to ON when Hum noise may be generated when external bridge-connecting Channels 3 and 4. equipment is connected to the unit. Connecting this terminal to the functional ground terminal of • 2-chan
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8. CONNECTIONS 8.1. Procedure Step 1. Switch off the unit's power. BRIDGE 2 BRIDGE 1 ON/OFF button ON/OFF button Step 2. Set the BRIDGE ON/OFF buttons and CH 1 mode ON/OFF button. Step 3. Connect the sound source equipment to the Input terminals. Note Refer to p. 12 for the removable terminal plug CH 1 mode ON/OFF button connection. Step 4. Connect speakers to the Speaker output terminals. 4-1. Unscrew the output terminal cover. 4-2. Strip 10 mm of insulative jacket from the end of the speaker
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[2 inputs - 2 outputs] Speaker output terminals CH1 Button Setting CH1 BRIDGE 1 ON CH2 - + - + BRIDGE 2 ON BRIDGE 2 BRIDGE 1 DA-250F DA-250FH CH 1 mode OFF CH3 + 8 – 16 Ω 39.2 Ω CH3 – CH4 + 8 – 16 Ω 39.2 Ω – [1 input - 2 outputs] Speaker output terminals CH1 Button Setting CH1 BRIDGE 1 ON CH2 - + - + BRIDGE 2 ON BRIDGE 2 BRIDGE 1 DA-250F DA-250FH CH 1 mode ON CH3 + 8 – 16 Ω 39.2 Ω – CH4 + 8 – 16 Ω 39.2 Ω – [3 inputs - 3 outputs (1)] Speaker output terminals CH2 CH1 CH1 Button Setting - + - + CH1
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[1 input - 3 outputs (2)] Speaker output terminals CH4 CH3 CH1 - + - + Button Setting CH1 BRIDGE 1 ON CH2 - + BRIDGE 2 OFF BRIDGE 1 CH 1 mode ON DA-250F DA-250FH CH3 + 8 – 16 Ω 39.2 Ω – CH4 + 4 – 8 Ω 19.6 Ω – + 4 – 8 Ω 19.6 Ω – 9. REMOVABLE TERMINAL PLUG CONNECTION 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
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10. INPUT SENSITIVITY AND HIGH-PASS FILTER ON/OFF SETTINGS The Input sensitivity can be set to +4 dB (factory-preset) or -10 dB for each channel. Besides, only the DA-250FH employs the High-pass filter on each channel, which can be set to "ON" or "OFF." 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
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11. PROTECTION OPERATION LIST Failure Protection Operation Indicator Remedy Recovery Overcurrent due Current limiter activated Peak indicator lights. Remove overload. Connecting a correct load to overload when impedance drops automatically restores below the specified normal operation. value. Short circuit Current limiter activated. Protection indicator Check speakers and Turn off the power switch. Load is disconnected. lights. lines for short circuit. Correct the load, then switch on the
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13. CLEANING THE FILTER Step 1. Switch off the unit's power. 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. 2 Ventilation Panel Detach the panel by pressing on the left and right sides. 3 Filter 15
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14. BLOCK DIAGRAMS 14.1. DA-250F 16 CH 1 CH 1 INPUT OUTPUT OUTPUT 1 H relay C + E - Current Limitter +4 dB Short Detector CH 1 volume -10 dB Protection Circuit BRIDGE 1 control OUTPUT CH 1 sensitivity OUTPUT 2 CH 2 INPUT selection jumper ON relay (+4 dB/-10 dB) H + C - E Current Limitter OFF CH 2 BRIDGE 1 ON/OFF switch Short Detector OUTPUT +4 dB CH 2 Protection Circuit volume -10 dB CH 3 control OUTPUT CH 2 sensitivity CH 3 INPUT OUTPUT 3 selection jumper relay H (+4 dB/-10 dB) + C - E Curren
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14.2. DA-250FH 17 CH 1 INPUT CH 1 OUTPUT H OUTPUT 1 C relay + E OFF - HPF ON Current Limitter 50 Hz +4 dB CH 1 Short Detector CH 1 HPF volume -10 dB ON/OFF jumper BRIDGE 1 control Protection Circuit OUTPUT CH 1 sensitivity CH 2 INPUT selection jumper OUTPUT 2 ON (+4 dB/-10 dB) H relay + C - OFF E ON HPF OFF Current Limitter CH 2 50 Hz BRIDGE 1 ON/OFF OUTPUT +4 dB Short Detector switch CH 2 CH 2 HPF volume -10 dB ON/OFF jumper Protection Circuit control CH 3 CH 2 sensitivity CH 3 INPUT OUTPU
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15. DIMENSIONAL DIAGRAM Unit: mm 465 482 18 31.8 44 374 20 400
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16. SPECIFICATIONS Model DA-250F CU DA-250FH CU Power Source 120 V AC, 50/60 Hz Power Consumption 200 W (at 1/8 rated output x 4 channels) Output 4 channels: 250 W x 4 (4 Ω ), 4 channels: 250 W x 4 (19.6 Ω ) 170 W x 4 (8 Ω ) 2 channels (bridge connection): 2 channels (bridge connection): 500 W x 2 (39.2 Ω ) 500 W x 2 (8 Ω ) Frequency Response 20 Hz – 20 kHz (±1 dB) 50 Hz – 20 kHz (–3 dB, +0 dB) (HPF ON) 20 Hz – 20 kHz (±1 dB) (HPF OFF) Total Harmonic 0.15% (1 kHz) 0.15% (1 kHz) Distortion 0.3% (
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Printed in Japan 133-22-027-00
