by Pat Brown
What is a Digital Audio Cable?
The audio interface provides the means of getting the signal from one component to the next. It includes the source (output) circuit, the cable, and the load (input) circuit. There are consumer (2-wire, unbalanced) and professional (3-wire, balanced) versions, the major difference being robustness against electromagnetic interference in its various forms (Fig. 1). Does a digital audio interface require a digital audio cable?
Since increasing the cable length can have a detrimental affect on both analog and digital audio signals, the use of balanced interfaces is mandated for large room systems. A cable contains multiple wires, or conductors. A cable designed for an unbalanced interface has a two conductors, one of which is a shield. A cable designed for a balanced interface has three conductors consisting of a twisted-pair and shield (STP). For this reason, the cable itself may be referred to as unbalanced or balanced. I’ll limit this article to a discussion of balanced interfaces and cables.
Do balanced analog and digital interfaces require different cables? I will first lay some groundwork. (more…)