Toa DA-250D User manual

DA-250D/250DH
Dual-Channel Digital Power Amplifiers
DESCRIPTION
FEATURES
The TOA DA-250D and DA-250DH dual-channel power amplifiers offer a wider choice of power ratings, advanced Class D
amplification circuitry, and a highly efficient AC mains to output power ratio, for the complete technological superiority it takes
to support long-term installation applications. These energy-efficient, space-saving amplifiers are designed to combine high
levels of performance and efficiency, and are well-suited to ensure sound reinforcement reliability in a wide range of venue
types. The DA-250D is ideal for dual-zone applications such as presentation and press-conference rooms, restaurants and
similar-sized locations. The DA-250DH is well-suited to such locations as exhibition halls, sports facilities, multipurpose halls
and houses of worship.
DA-250D
DA-250DH
•High efficiency
Extremely high amplification efficiency of 80-90%, resulting in reduction in power
consumption by more than 60% compared with Class-AB amplifiers.
•Highly durable
Stands up to extended hours of operation. The DA amplifier has undergone a large
number of rigorous tests to prove its durability. In addition,TOA has been conducting
a “non-stop driving test” of the DA Series.
•High reliability
The DA amplifier has a comprehensive protection circuitry for protection against excessive
current flow due to overload, short circuit, unusual DC voltage output, and power amplifier
heat sink temperature rise ( over 100°C), temperature rise inside the unit (over 80°).
•Amplifier with lightweight design
Installation has become much easier thanks to the lightweight design.
•Compact design
The DA-250 Series is 1-unit size, and they can be efficiently mounted on a rack, so they
require only a small installation space. Because the amplifiers do not generate much
heat, 5 units can be stacked together in a rack.
•Independent power supply
Each of the channels has its own power supply. If the power supply of Channel 1 should
fail, this won't affect the operation of Channel 2. It is also possible to use the either
channel as a spare amplifier.
Conventional AB-class Amplifier
DA Series Amplifier
Efficiency (%)
Output (%)
100
90
80
70
60
50
40
30
20
10
0 2040 60 80 100
CU Version

110100 1k 10k 100k
[Hz]
[dB]
0
-2
-4
-6
-8
-10
-12
-14
-16
-18
Output
1/8W 19.6Ω
Frequency
DA-250DH Frequency Response
-5 110100 1k 10k 100k
[Hz]
[dB]
0
-1
-2
-3
-4
Output
1/8W 8Ω
1/8W 4Ω
Frequency
DA-250D Frequency Response
10 100 1k 10k 100k
[Hz]
[dB]
-65
-70
-75
-80
-85
-90
-95
-100
Output
ch2
Frequency
DA-250DH Channel Seperation
020406080100
[%]
[%]
90
80
70
60
50
40
30
20
10
0
Output
Output
Efficiency vs Output
DA-250D (4Ωdrive)
DA-250D (8Ωdrive)
DA-250DH (19.6Ωdrive)
10 100 1k 10k 100k
[Hz]
[dB]
-65
-70
-75
-80
-85
-90
-95
-100
Output
ch2
Frequency
DA-250D Channel Seperation
0.1 1 10 100 1k
[W]
[%]
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
-0.2
Output
Power Output
4Ω1kHz
8Ω20kHz 8Ω20Hz
8Ω1kHz
4Ω20Hz
4Ω20kHz
DA-250D T.H.D vs Power Output
0.1 1 10 100 1k
[W]
[%]
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
-0.2
Output
40Ω1kHz 40Ω50Hz
40Ω20kHz
Power Output
DA-250DH T.H.D vs Power Output
APPEARANCE AND DIMENSIONAL DIAGRAM
Unit: mm
Rear View
401.8 (15.82")
371(14.61") 22.5 (0.89")
Side View
44
(1.73")
6.1 (0.24") 31.8 (1.25")
482 (18.98")
465 (18.31")
442 (17.4")
Front View

OPTION
Unit: mm
MT-251H
•Capacity: 0W – 250W
•Primary Side: 100V line, 70V line
•Secondary Side: 100V line, 70V line, 50V line, 35V line
•Frequency Response: 30 – 18,000Hz (+0dB, –3dB)
•Connection Terminal: M3 screw terminal, distance between barriers: 6.6mm (0.26")
•Dimensions: 108 (W) ×80 (H) ×122 (D)mm (4.25" ×3.15" ×4.80")
•Weight: 2.4kg (5.29 lb)
Max. 80 (Max. 3.15")
4–5X7 (0.2" X 0.28")
97 (3.82")
108 (4.25")
66 (2.6") 94 (3.7")
122 (4.8")
Front View Side View
Matching Transformer
Designed for use with the DA-250DH Dual-Channel Power
Amplifier (option), the MT-251H electrically isolates the high-
impedance speaker lines from the amplifier.
DA-250D SPECIFICATIONS
The dual-channel power amplifier shall use class-D circuit topology and
shall be configurable to two channel operation. Power output in wo-
channel mode with all channels driven shall be: 250W per channel into 4
ohms and 170W per channel into 8 ohms. Each pair of channels shall be
bridgeable to produce 500 W. Total harmonic distortion (THD) shall be
less than 0.1% @ 1 kHz, 0.3 % (20 to 20,000 Hz). The frequency response
shall be 20 to 20,000 Hz (±1 dB). The signal to noise ratio shall be 100 dB
(A-weighted). The crosstalk shall be 70 dB (A-weighted). The input
impedance shall be 10k ohms for each input into an electronically
balanced input circuit. Rear panel switches shall allow selection of
bridged operation for 1-2 channels. A rear channel input mode switch
shall allow the selection of input 1 to all mode, whereby the signal from
input 1 is simultaneously fed to other channel. Each input shall feature a 3
pin phoenix block and XLR connector. Rear panel output connector shall
be a heavy-gauge M4 screw-terminal barrier strip suitable for use with
spade lugs or up to #12 AWG bare wires. The front panel attenuators shall
be recessed to prevent accidental level changes and may be removed
and replaced by included security covers once levels have been properly
set. The front panel shall have two sets of four LED indicators to indicate
the following conditions: signal presence at input (greater than -20 dB),
signal presence at output (greater than 1 W @ 8 ohms load), peak clipping
and protection circuit activation. The front panel shall also have two
removable air filters that may be removed for cleaning without removing
the amplifier from the rack. The amplifier shall be forced-air fan cooled
with the air intake at the front and exhaust at the rear.
Built-in protection circuitry shall monitor voltage and current levels to
minimize potential damage from overloads, and disable output during
shorts, DC offset, or excessive operating temperature at power amp heat
sink over 212°F (100°C), or excessive operating temperature inside the
unit over 176°F (80°C) via a relay for each channel. The relay shall also
delay amplifier connection to the load during turn-on for about 2 seconds,
so as to prevent any occurrence of noise at turn-on. Power consumption
shall be 120 W (based on UL/CSA standards) and 650 W (rated output 4
ohms x 2 channels), and 420 W (rated output at 8 ohms x 2 channels).
The amplifier shall use only one standard rack-spaces or 1.75" (44.5 mm)
and its dimensions shall be 18.98" (W) x 1.73" (H) x 15.82" (D) (482 x 44 x
401.8 mm). Front panel finish shall be black anodized aluminum and case
finish shall be sheet steel. Weight shall be 11.02 lb (5 kg).
The amplifier shall be a TOA model DA-250D.
DA-250DH SPECIFICATIONS
The dual-channel power amplifier shall use class-D circuit topology and
shall be configurable to two channel operation. Power output in two-
channel mode with all channels driven shall be: 250W per channel into
19.6 ohms (70V). A pair of channels shall be bridgeable to produce 500W
into 39.2 ohms (140V). Total harmonic distortion (THD) shall be less than
0.1% @ 1 kHz, 0.3 % (20 to 20,000 Hz) HPF OFF, and 0.3 % (100 to
20,000 Hz) HPF ON. The frequency response shall be 50 to 20,000 Hz (-3
dB, +1 dB) HPF ON. The frequency response shall be 20 to 20,000 Hz (±1
dB) HPF OFF. The signal to noise ratio shall be 100 dB (A-weighted).
The crosstalk shall be 70 dB (A-weighted). The input impedance shall be
10k ohms for each input into an electronically balanced input circuit. Rear-
panel switch shall allow selection of bridged operation. The amplifier shall
operate in 2-channel mode when the switch is deselected.
A rear-panel input mode switch shall allow the selection of input 1 to all
mode, whereby the signal from input 1 is simultaneously fed to the other
channel. Each input shall feature a 3 pin phoenix block and XLR
connector. Rear panel output connector shall be a heavy-gauge M4
screw-terminal barrier strip suitable for use with spade lugs or up to #12
AWG bare wires.
The front panel attenuators shall be recessed to prevent accidental level
changes and may be removed and replaced by included security covers
once levels have been properly set. A dip switch on the rear of the unit
shall allow independent on/off selection of a 50 Hz (-6 dB/Oct) high-pass
filter (HPF) cut-off for protection against excessive low frequency loading
and saturation of speaker transformers.
The front panel shall have two sets of four LED indicators to indicate the
following conditions: signal presence at input (greater than -20 dB), signal
presence at output (greater than 1 W @ 19.6 ohms load), peak clipping,
and protection circuit activation. The front panel shall also have two
removable air filters that may be removed for cleaning without removing
the amplifier from the rack. The amplifier shall be forced-air fan cooled
with the air intake at the front and exhaust at the rear.
Built-in protection circuitry shall monitor voltage and current levels to
minimize potential damage from overloads and disable output during
shorts, DC offset or excessive operating temperatur at power supply heat
sink over 212°F (100°C) or excessive operating temperature inside the
unit over 176°F (80°C) via a relay for each channel. The relay shall also
delay amplifier connection to the load during turn-on for about 2 seconds,
so as to prevent any occurrence of noise at turn-on. Power consumption
shall be 120 W (based on UL/CSA standards) and 580W (rated output
19.6 ohms x 2 channels).
The amplifier shall use only one standard rack-space or 1.75" (44.5m) and
its dimensions shall be 18.98" (W) x 1.73" (H) x 15.82" (D) (482 x 44 x
401.8 mm). Front panel finish shall be black anodized aluminum and
case finish shall be sheet steel. Weight shall be 11.02 lb (5 kg).
The amplifier shall be a TOA model DA-250DH.
The optimal 1:1 line isolation transformer shall be TOA model MT-251H.
ARCHITECTURAL AND ENGINEERING SPECIFICATIONS

Specifications are subject to change without notice.
Printed in Japan (0803) 833-52-389-30 u
TOA Corporation
www.toa.jp
SPECIFICATIONS
Model DA-250D DA-250DH
Power Source 120V AC, 50/60Hz
Number of Channels 2
Total Output All Channel Driven 500W (1kHz, 4Ω)500W (1kHz, 19.6Ω: 70V line)
340W (1kHz, 8Ω)
Output Voltage per Channel 31.6V (1kHz, 4Ω)70V (1kHz, 19.6Ω: 70V line)
36.9V (1kHz, 8Ω)
Output Current per Channel 7.9A (1kHz, 4Ω)3.6A (1kHz, 19.6Ω: 70V line)
4.6A (1kHz, 8Ω)
Power Output
8 ohms per channel 170W —
4 ohms per channel 250W —
16 ohms bridged 340W —
8 ohms bridged 500W —
Hi-Z: 70V per channel —250W
Hi-Z: 140V bridged, per channel —500W
Power Consumption*
Idle power consumption 28W, 0.5A 35W, 0.7A
Rated power consumption
1kHz 8 ohms 420W, 5.9A —
4 ohms 650W, 8.7A —
70 Volts —580W, 7.8A
1/8 Power Pink noise*18 ohms 102W, 1.7A —
4 ohms 132W, 2.3A —
70 Volts —147W, 2.3A
1/3 Power Pink noise*28 ohms 197W, 3.1A —
4 ohms 308W, 4.4A —
70 Volts —311W, 4.5A
1/8 Power 1kHz 8 ohms 84W, 1.4A —
4 ohms 112W, 1.8A —
70 Volts —123W, 2.0A
1/3 Power 1kHz 8 ohms 160W, 2.5A —
4 ohms 222W, 3.4A —
70 Volts —256W, 3.8A
Frequency Response 20Hz – 20kHz (±1dB) HPF ON: 50Hz – 20kHz (–3dB, +1dB)
HPF OFF: 20Hz – 20kHz (±1dB)
THD 0.1 % (1kHz) HPF ON: 0.1% (1kHz)
0.3% (20Hz – 20kHz) 0.3% (100Hz – 20kHz)
HPF OFF: 0.1% (1kHz)
0.3% (20Hz – 20kHz)
S/N Ratio (A weighted) 100dB
Crosstalk at 10kHz (A weighted) 70dB
DC Offset* ±5mV
Voltage Gain* 29.5dB 35.1dB
Damping Factor* 100 (1kHz, 8Ω)220 (1kHz, 19.6Ω: 70V line)
Inputs
Input impedance 10kΩ(unbalanced), 20kΩ(balanced)
Input sensitivity +4dB (1.23V)
Input clipping 14V (25.1dBu)
Protection Circuit Amplifier section DC output, overheat protection, load shorting, overload current, maximum output
Power supply section Overheat protection, AC rush current
Cooling Continuously constant speed fan with front-to-rear airflow,
50,000 hours life time at 25°C (77°F)
Operating Temperature –10°C to +40°C (14°F to 104°F)
Operating Humidity Under 90% RH (no condensation)
Dimensions 482 (W) × 44 (H) × 401.8 (D)mm (18.98" x 1.73" x 15.82") (EIA Standard 19-inch rack mount width)
Weight 5kg (11.02 lb)
Finish Panel: Aluminum, alumite process, black
Case: Plated steel sheet
Accessories Euro style terminal block connector (3-pin) ×2, Tamper-proof cap ×2
Option — Matching transformer: MT-251H
0dB=0.775Vrms
*Typical data
*11/8 power with pink noise represents typical program with occasional clipping.
*21/3 power with pink noise represents severe program with heavy clipping.