XLR

XLR refers to a family of electrical connectors originally designed by Cannon Electric (now ITT Cannon) for professional audio applications. XLR connectors are circular, locking, and typically come in 3-pin variants but also in 4-, 5-, 6-, and 7-pin configurations. They are designed to carry balanced audio signals and, in some uses, power.

Construction and variants: The 3-pin XLR is the most common, with a male connector containing three pins and a female containing three sockets, paired with a latch-release coupling that locks when mated. The 4- and 5-pin variants extend capability for additional signals, with 4-pin often used for power in certain equipment and 5-pin widely used for DMX512 lighting control. Higher pin-count versions exist but are less common in typical audio setups.

Electrical usage: In a standard 3-pin XLR, pin 1 is ground, pin 2 is hot, and pin 3 is cold. XLR cables are typically used as balanced lines, which helps reject noise over long runs. They can also carry phantom power (commonly up to 48 volts) on the signal conductors to power condenser microphones, provided the connected devices support this arrangement.

Applications: XLR connectors are ubiquitous in live sound, recording studios, broadcast environments, and stage lighting. They are used for microphones, line-level and preamp connections, and for DMX lighting control when multiple pins are employed. Their robust design makes them a standard component across professional audio equipment.

Durability and standards: XLR connectors are built to withstand frequent mating cycles and rough handling in performance environments. They enjoy broad compatibility across manufacturers and remain a de facto standard for many professional audio and stage lighting applications.