In message , chris
writes
This should be true ! BUT. Unfortunatly due to the design spec this
is not true.
There was some deep discussion on this whole issue a while back on
RAHE,
I too had thought like you. Then The Man from Belden explaind it
rather well: you could do a google on it his expanation should be a
lot better than mine.
But basically the Fibre call for in the spec is many times larger in
diameter that the wavelenght of the light used so instead on the light
bouncing down the fibre in a controlled fashon it bounces about in a
lot more random fashon and after a metre or three the uncontrolled
light bounces interfere with the main light signal generating extra
noise. This can cause misreading of the recieved signals, hence
errors, noise, distortion.
So by using a better fibre (which is not as cheap) that has a smaller
diameter, will improve the quality (by reducing the noise) at the
recieving end, resulting in less errors etc.


All audio fibre-optic links use multimode fibre. Single mode fibre
(with no bouncing about) is only used on telecomms links at hundreds and
more Megabits/sec.

At the VERY low bit rate used for SPDIF it really doesn't matter a damn.

Likewise, as many others have pointed out, for cable runs of a metre or
so, phono-plugs are quite OK for copper connections. Use a proper
RG-spec cable and BNC connectors for long lengths by all means.

I'm now playing with multi-channel 24bit, 48kHz sample-rate pro-audio
over Cobranet at work. Have a look at the Cirrus web site, some
seriously good work being done on the distribution of digital audio
feeds there.
--
Chris Morriss