Supervises both main and standby power amplifiers. Automatically transfers operation to standby power amplifier. LEDs and fault alert tone notify user of a 2 dB or greater drop in either amplifier s output. Automatically restores operation to main power amplifier when trouble is corrected. Rear-panel screwdriver-adjustable controls for setting the oscillator level and the detector levels and sensitivities. Operates with 25V or 70V constant-voltage systems, balanced or unbalanced. Screw terminal or phone jack connections. Operates from 120V AC or 12V DC. Standard 19-inch rack mounting. Front panel made of #16-gauge cold-rolled steel, finished in black enamel.