DA-250F/DA-250FH TOA Corporation

Features

DA Series Multi-channel Digital Amplifiers

DA Series

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

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

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

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

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.) – VAC version  Independent power supply for each channel

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

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

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

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

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

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

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

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

Digital Amplifiers

DA-250FH: Block Diagram 120VAC version

DA-250F: Block Diagram

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

Technical Fields

Working Outline Class-ABClass-D

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