The UB400 is interface amplifiers designed to interconnect consumer grade and semi-professional equipment into professional, balanced, low impedance audio systems. The UB400 is a uni - directional four-channel interface that converts four IHF level signals into four balanced professional outputs. The UB400 is particularly useful in protecting the four, eight or sixteen main or monitoring IHF outputs of low cost mixers and tape decks. The UB400 is also a very low cost way to interconnect two CD players into a balanced system.