AudioQuest Optilink Pearl Full Size to Full Size Digital Audio Cable (8 M)

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.

While thanks to HDMI Toslink is not so often used to connect a DVD player to an A/V receiver Toslink connectors are common on cable-boxes TV sets subwoofers all sorts of products. And now the 3.5mm Mini Optical connector also somewhat incorrectly known as Mini-Toslink is everywhere from the 3.5mm dual-purpose headphone jack on a Mac laptop to inputs on some of the finest portables.

For these many reasons AudioQuest has refined and renewed our line of serious high performance OptiLink cables. All models and all lengths are now available Toslink to Toslink and Toslink to 3.5mm Mini Optical.

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.

There is another serious dispersal mechanism in the Toslink system. The fiber is a relatively huge 1.0mm in diameter and the LED light source is also relatively large spraying light into the fiber at many different angles. Even if the fiber were absolutely perfect the signal would be spread across time because light rays entering at different angles take different length paths and arrives with different amounts of delay.