Phonic XP Series power amplifiers deliver from 280 to 5000 Watts of power in two to three rack spaces. Built around robust and advanced toroidal transformers, they deliver clean power on demand. The advanced protection circuitry guards against short circuit and open circuit, and also protects against ultrasonic and RF interference. A high current power supply increases reliability and performance. Other features include center-detented gain controls, input peak limiter, selectable high pass filter, and fast recovery to ensure low distortion. The variable speed fans effectively cool the amp and protect against overheating. Input is through XLR or 1/4" connectors, while you can use Speakon-type or binding post connectors for output. The XP 2100, 3100 and 5100 power amps have sub woofer outputs with a selectable low pass filter at 60, 90 or 120 Hz. Phonic XP Power Amplifiers are specially designed for professionals who value high power, audio clarity, reliability and lasting performance.