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DA-250F/DA-250FH TOA Corporation

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Features

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DA Series Multi-channel Digital Amplifiers

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DA Series

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DA Series Models DA-250FH: 4x 250W (70V/100V) DA-250F: 4x 250W (4 ohm)

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DA Series Models DA-250FH 4x 250W (70V/100V) 2x 500W bridged mode (140V) *120VAC Version only Limiter

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DA Series Models DA-250F 4x 250W (4 ohms) / 170W (8 ohms) 2x 500W bridged mode (8 ohms) Limiter

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DA Series Four 250 Watt amplifier channels in one rack space!

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DA Series Features Class D design 85% efficient! 60% lower power consumption than conventional amplifiers Compact, single rack-space design Stack up to 5 units without open spaces between units Lightweight 6.6kg (14.6 lbs.) 120VAC version 6.8kg (15.0 lbs.) 220-240VAC version Independent power supply for each channel

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DA Series Features Low heat dissipation Recessed stepped attenuators Comprehensive protection circuitry Removable dust filters for easy maintenance Optional 250W output transformer, model MT- 250H

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DA Series Front Panel Channel #1 Channel #2Channel #3 Channel #4

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DA Series Front Panel Recessed stepped attenuators Input, Output, Peak and Protect indicators Power On/Off Removable Dust Filter

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DA Series Rear Panel Removable AC connection Power amplifier outputs w/ protective cover plate Balanced inputs (+4/-10 dBu)

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DA Series Input Section CH1 to All Switch Bridge 2 Switch Bridge 1 Switch

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DA Series Power Supply Separate power supply on each amplifier channel!

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Stack up to five units! Twenty amplifier channels in only five rack spaces! Rack Mounting

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Class D Advantages High power efficiency Smaller heat sink and power supply Less heat Increased reliability

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Digital Amplifiers

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DA-250FH: Block Diagram 120VAC version

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DA-250F: Block Diagram

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MT-250 Matching Transformer Low frequency response down to 30Hz! Up to 250W

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Technical Fields

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Working Outline Class-ABClass-D

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The method of Class-D Amplification Class-D Amplifier changes input signals into digital pulse signals in PWM and then amplifies it. Output signals are also come out as digital pulses, and audio signals are extracted by using LPF. Class-AB amplifier linearly amplifies input signals. A waveform amplified does not change after amplification. Amp Input signal Output signal PWM Input signal AmpLPF Output signal Digital pulse Output signal