Connectors

A wide variety of connector and cable types are found in the typical audio configuration.

Shielded cables of different sizes are used in combination with the appropriate connector type.

Usually the RCA
type connectors, due to their small size, use the smallest cable,

with Phone
connectors using a larger cable

and
XLR
using the most robust type for microphone and amplifier/speaker applications.

RCA

advantages

small, efficent use of space
easily connected

disadvantages

small wire diameter higher resistance and capacitance suseptible to higher resistance due to corrosion (use gold plated connectors) hard to make effective shield connections during manufacture easily pulled out (unlocked)

Phone

advantages

cheap
easily wired

types: (comes in 1/8 - mini, 1/4 - standard and 3/16 - Bantam)

stereo mono, balanced
tip/ring/sleeve
tip = hot or high
ring = low
sleeve = ground
mono, unbalanced
tip/sleeve
tip = hot or high
sleeve = ground
t/s/r also used in patchbays and is a slightly different design in those applications. see t/s/r.
A slightly smaller t/s/r called "bantam"is also used in patchbays to save on space.

disadvantages

can pop or crackle when inserted or removed easily pulled out (unlocked) susceptible to mechanical stress and breakage from the side due to their length.

XLR (canon)

XLR connectors use a three pin system to accomodate a shield or ground wire and two wires for the program signal. Pin 1 is always wired to the ground or shield. There are, however, inconsistencies in the way the other two connectors are wired. The most common standard favours "pin 2 hot" with the red (or white) wire connected to pin 2 and the black return wire connected to pin 3.

advantages

not easily removed (locked)
large, robust construction
accomodates large wiring
pin 1 (ground) connects first so electrostatic and ground differences responsible for "pops" are discharged before the audio wires make contact

disadvantages

expensive

Also common, especially to Macintosh computers and some portable audio equipment (Sony Pro Walkmans, etc.) is the mini stereo plug not pictured. This connector is similar in design to the phono plug but miniature. The following list gives the most common connector types for several different input and output connections:

mic inputs	line inputs	outputs	loudspeakers
balanced XLR/Canon unbalanced phone/1/4"	RCA Phone/1/4"	Phone/1/4" XLR RCA	Phone/1/4" Banana plugs XLR RCA