Hello,
my experience with digital cables is mixed. First let me state that I am a believer that cables make a noticeable sonic difference, All of my power cables have been replaced with high quality aftermarket cables, I use some quite exotic cables for analogue both single ended and balanced, and I run bi -wire cables to my SL-3's.
Now digital lines are another thing entirely. I'll start off with the worst, TOSLink, which always loses focus in the imaging regardless of the component or TOSLink cable used. Invariably coax is better, with my two favourite formats, AES/EBU and AT&T Glass optical, someway ahead of this, sadly these two formats are not as widely supported as I would like to see, as AES/EBU is much cleaner with far superior soundstaging, as is glass optical.
Coax digital is a bit of an odd one. Theoretically the cable used here will make no difference whatsoever, as lone as the output transmitter and the input receiver 'see' a 75 ohm line. This is where things go pear shaped, not all transmitters and receivers are actually implemented in spec, and most RCA cables are not 75 ohm either, as the RCA connector was never designed to be a 75 ohm connector, with only the WBT NextGen and Canare currently supplying true 75 ohm RCA Phono connectors. In a system with true 75 Ohm transmitters and receivers then the cable should make negligible difference, indeed I used a cable made from Belden video cable using a pair of Neutrik professional RCA connectors for a long time very successfully. Right now I'm using the same cable terminated in the WBT NextGen RCA plugs and this has proved to be an excellent cable. If, on the other hand, the Rx or the Tx are not tru 75 ohm devices, then the cable can potentially make a large difference, not because it is better, but because it is either rectifying or worsening the impedance mismatch between the Rx and Tx ends.
As a footnote to this, I was speaking to an engineer with a decades experience at a local BBC station, where he worked on the outside broadcast vehicles, and on one occasion arrived at a site only to discover that their digital feed was supplied by an S/PDIF coax, without an AES/EBU connector in site. Forutnately there was a 30 ft length of coax cable, which he reterminated and connected up. The link not only worked, but continued to work for 4 hours without a dropout of problem. I'll leave you to draw your own conclusions about the integrity of the S/PDIF link.
In short, try using something very simple and cheap, if that works, don't always assume that just because a cable is more expensive, it will perform better in your system.
Best wishes,
Dave
