Also known as an XLR-connector, a professional audio connector for balanced audio signals. Pin 1 is connected to the cable shield, pin 2 connects to the signal hot lead and the third pin is connected to the signal return lead. Sometimes equipment is manufactured with pin 2 and 3 reversed, which causes problems when going from a balanced line to an unbalanced line.
THREE-PIN CONNECTOR
Meaning of THREE-PIN CONNECTOR in English
Guitar English glossary. Английский словарь гитарных терминов . 2012