From the Mouth of the Sun's "Sitting In a Roofless Room," from the new album Woven Tide, released by Experimedia.

Back in the late 1980s, it seemed a good idea: Separate a CD player's transport section from its D/A circuitry so that each could be optimally designed, and, as D/A technology improved, the sound of your CD player could be upgraded by replacing the outboard D/A processor. The catch was that the transport and D/A chassis needed to be connected with a serial data link: S/PDIF in optical or electrical flavors, or balanced AES/EBU. To minimize the number of cables required, the format of that link embedded the clock data within the audio data, which rendered the link sensitive to interface timing uncertainty, or jitter. (See "Bits Is Bits?," by Malcolm Hawksford and Chris Dunn.)