The dual-channel power amplifier shall use digital class-D circuit topology and shall be configurable to allow two channel operation. Power output in two-channel mode with all channels driven shall be: 250W per channel into 4 ohms and 170W per channel into 8 ohms. A pair of channels shall be bridgeable to produce 500 W. Total harmonic distortion (THD) shall be less than 0.1% (1kHz), 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 100°C, or excessive temperature inside the unit over 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 EN standards) and 620 W (rated output 4 ohms x 2 channels), and 400 W (rated output at 8 ohms x 2 channels).The amplifier shall use only one standard rack-space or 44.5 mm and its dimensions shall be 482 (W) x 44 (H) x 401.8 (D) mm. Front panel finish shall be black anodized aluminum and case finish shall be sheet steel. Weight shall be 5.3 kg.

The amplifier shall be a TOA model DA-250D.