(BALanced UNbalanced) An adapter that connects a balanced line to an unbalanced line such as from XLR to RCA. A balanced line is one in which both wires are electrically equal. In an unbalanced line, such as a coax, one line has different properties from the other. See XLR connector and RCA connector.
A passive device, often a transformer, used to couple an electrically balanced device, medium, or system and an electrically unbalanced device, medium, or system. A balun commonly is used to connect an electrically balanced twisted pair to an electrically unbalanced coaxial cable. The term balun is a contraction of balanced to unbalanced transformer. See also balanced, coaxial cable, passive, transformer, twisted pair, and unbalanced.