Lower-Dispersion Higher-Purity Fiber Conductors
The problem with optical fiber transmission is that dispersed light does get through the Toslink 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 the information from being decoded properly, or even at all. This 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.