AudioQuest Pearl Series 3 Meter (9.9 Feet) Digital Optical Cable

AUDIO QUEST

  • $ 43.95

OptiLink 3m Optical Cable
The audio frontier is all abuzz these days with the pleasure possible though HDMI, USB, FireWire® and Ethernet connections. However, these current generation digital technologies are only part of the story, just as the challenge of designing, manufacturing and choosing the best analog interconnects and speaker cables is as important as ever. The S/P-DIF (Sony® Philips Digital InterFace), which arrived in 1983 along with the CD, is still very much a part of our world today. S/P-DIF is transmitted through Digital Coax and Toslink fiber optics (EIA-J), making them still some of the most important cables in electronic entertainment.

When the question is "how can a fiber-optic cable change the sound?" ... the answer is easier to explain than for almost any other type of cable. If the light source were a coherent laser, firing into a vacuum, all the light would stay straight, arriving at its destination at the same time. Even if the LED light source in a Toslink system were coherent, the light entering a fiber-optic cable is scattered and dispersed by imperfections and impurities in the fiber. This can be measured as a loss of amplitude ... but amplitude is not the problem, a 50% true loss would have no effect on sound quality.

The problem is that the dispersed light does get through the cable, but only after it has taken a longer path, like a pool ball bouncing off the side-rails, causing it to arrive later. This delayed part of the signal prevents the computer charged with decoding this information from being able to decode properly, or even at all. The inability to decode shows first at higher frequencies (not audio frequencies, this is a mono stream of digital audio information), so reduced bandwidth is a measurable signature of light being dispersed by a fiber. The punch line: The less dispersion in the fiber, the less distortion in the final analog audio signal presented to our ears.