The audio frontier is all abuzz today with the pleasure possible over HDMI, USB, FireWire®, and Ethernet connections. However, these current generation digital technologies are only part of the story, and 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 alongside CD, is still a huge part of our world today. S / P-DIF is transmitted over Digital Coax and Toslink fiber optic (EIA-J), making them still some of the most important cables in electronic entertainment.

While, thanks to HDMI, Toslink is not as often used to connect a DVD player to an A / V receiver, Toslink connectors are common in cable boxes, televisions, subwoofers, all kinds of products. And now the 3.5mm mini optical jack, aka Mini-Toslink, is everywhere ... from the 3.5mm dual-purpose headphone jack on a Mac laptop, to inputs on some of the best laptops.

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

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

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

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

The almost complete solution to this problem is to use hundreds of much smaller fibers in a 1.0mm bundle. Because each fiber is limited as to what angle of entry it can enter the fiber, there is much less variety, and much less dispersion over time. This narrow aperture effect is similar to how a pinhole camera can take a picture without a lens ... by letting light in at only a very limited range of angles, you can take a picture while removing the lens of a wider aperture would make photography impossible. Less light passes through a multi-fiber cable, but the light that enters the fibers exits within a much shorter time.

So there is a problem: the scattering of light through time ... and two ways to a better result: less scattering in the fiber (better polymers and finally quartz) and less scattering by filtering the angle of entry. How simple is that! Listen and enjoy.

• Low dispersion fiber

• Low jitter (digital timing errors)

• Precision polished fiber ends

• Black PVC with wall stripes