Word Clock

Although not technically a Digital Audio Cable format, Word Clock is an important aspect of digital audio cables. Digital audio cables require synchronization between sending and receiving. Some formats provide that sync along with the signal, while others do not. Word Clock is also useful for synching numerous devices together. One device acts as a Master Clock, which provides sync information for numerous devices (such as making multiple DAT duplications simultaneously).

Word clock is usually transmitted on 75 ohm BNC connector cables.

AES/EBU

AES/EBU is a 2 channel digital audio connection that supports most sampling rates. AES/EBU is one of the most typical connections that you will see on digital recorders like DAT decks and other hardware devices. Few audio cards have AES/EBU

Although AES/EBU uses the same XLR connector that you see on microphone cables, the actual cable is different. AES/EBU cables have an impedance of 110 ohm, while typical Mic cables are variable somewhere between 30 to 90 ohms. AES/EBU cables can be up to 300 feet long.

S/PDIF (Coaxial)

Coax S/P DIF uses an RCA style connection, which is the same connection tat you would find on the back of your home stereo or CD player. However, a single S/P DIF cable carries 2 channels of digital information. S/PDIF supports most resolutions and sampling rates.

Although it may look like the same cable you would connect on your stereo, it is not quite the same. S/P DIF uses a special 75-ohm cable.

S/PDIF Optical (TOSLink)

A variation of Coaxial S/P DIF is S/P DIF optical, also known as TOSLink. This is a very common connection for home electronics, such as DVD players, and can also be found on many audio cards and other musical equipment.

S/PDIF optical uses a special FiberOptic cable and can transmit 2 channels of audio at a time.

ADAT Optical (Lightpipe)

The Alesis corporation created ADAT Optical, also known as Lightpipe, for the Alesis ADAT digital recorders. Since their introduction, Lightpipe has also been used for many other devices.

Although it uses the same cable as S/P DIF optical, the information that it caries is not the same so you can not just plug a Lightpipe device into a S/P DIF optical connection.

ADAT machines also use a 9 Pin computer cable for synchronization.

TDIF (Tascam)

Tascam Digital Interchange Format (TDIF) was developed for use with the Tascam DA88 line of recorders. TDIF uses a special 25 pin cable for transferring digital audio. Like the ADAT, the DA88 also uses a special cable, in this case a 15 pin computer cable, for synchronizing of machines.

TDIF is a proprietary format for Tascam, and so, it has not seen the widespread implementation that Lightpipe has, although there are several audio cards available that use it.

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* Source : audioMIDI.com, AES India