The Toa DA-550F is a 4-Channel Digital Power Amplifier featuring lightweight, compact, high power output, and high efficiency. It delivers 550 W × 4 channels (4 Ω output) using a switching power supply. Each channel is equipped with an independent power section. Its Control/Monitor terminals permit power ON/OFF control of the individual channels and status monitoring for the power ON/OFF on each channel, protection on each channel, and fan operation. Prepare the control panel or status monitor display panel separately. It can be mounted in an EIA Standard equipment rack (2 unit size).