The XLR connector was invented in the 1950s by James H. Cannon, founder of Cannon Electric in Los Angeles, California and for this reason it was sometimes known as a Cannon plug or Cannon connector. Originally manufactured as the Cannon X series, subsequent versions added a locking (L) mechanism (Cannon XL) and then surrounded the female contacts with rubber (R) polychloroprene insulation, which extended the part number prefix to XLR.

XLR connectors are available in male with protruding pins and female with recessed pin-holes in both cable and adapter styles. The female XLR connectors are designed to first connect pin 1 (the earth pin), before the other pins make contact, when a male XLR connector is inserted. With the ground connection established before the signal lines are connected, the insertion (and removal) of XLR connectors in live equipment is possible without picking up external signals.

The most important quality of an XLR cable is that it is balanced, however an XLR cable can only deliver a balanced signal if both devices on either end of the signal are also balanced. If any of the devices in the chain are unbalanced, then the whole signal will be unbalanced. (Read our blog on Balanced Audio Cables) If you would like to learn more about the Selby range of XLR cables and adapters, feel free to speak with our Selby Techs by calling 1800 69 2225 or Viewing XLR Online