The Adastra 50W slave amplifier is for use with the 900 series compact mixer amplifiers or with any other suitable source. Featuring RCA sockets for input and output signals, front located master volume control. The 900 series compact amplifiers are housed in strong metal cases, two units can be mounted in a standard 19" rack cabinet. All amplifiers are fully protected for short circuit and overload with fuse protection for the DC power supply.