squeezebox set up for audiophiles

Have you read the official description from Denon? They still have this cable listed on their website, but as a discontinued product:

Denon's 1.5 meter (59 in.) proprietary ultra premium Denon Link cable was designed for the audio enthusiast. Made from high purity copper wire and high performance connection parts, the AK-DL1 will bring out all the nuances in digital audio reproduction from any of our Denon DVD players with the Denon Link feature connected to a Denon Link enabled Denon A/V receiver. The AK-DL1 employs high level tin-bearing alloy shielding not typically available in commercial cabling, to eliminate data loss caused by noise. Additionally, signal directional markings are provided for optimum signal transfer. Attention to detail when building this cable was used by employing high quality insulation and woven jacketing to reduce vibration and to add durability. Rounded plug levers help prevent breakage.

So in future, make sure you plug your ethernet cable in the right way round, and if the cable runs along the floor, tiptoe as you walk past so that your footsteps don't cause vibrations that could lead to data corruption

There's even an "Owners manual"...