Jack

The output socket of a guitar, and by extension the plug that fits it, normally a quarter-inch unbalanced connection.

The socket carries the signal on its tip contact and the ground on its sleeve, and in most guitars it also switches the battery in an active circuit. Because the cable hangs from the socket, this is the part of the instrument that takes the most mechanical abuse, and a jack that crackles or cuts out is usually a worn contact or a loose ground rather than a fault in the pickups. It also remains one of the few connectors in audio that has never been standardised away.

Example: a signal that cuts in and out when the cable is wiggled points to the jack rather than to anything in the rest of the chain.

Jack

See also