I sometimes use coaxial SPDIF
( but with an M-Audio Delta 66 pci card)
As far as the pc is concerned, it's just another input.
I do this because I have an AD converter which has better quality than the M-Audio Delta 66.
I use 75ohm cable, as I make my own cables it's just as easy/cheap.
I've heard it said that cables under 3m are not a good idea.
One thing is that the automated latency compensation by a multi-track audio app which made everything so easy in the past suddenly stops working because of the extra latency introduced by the external converters ( no way the pc can know about that)
all this info should be the same for Firewire.
(make sure your firewire interface can lock it's clock to the incoming spdif,
otherwise there'll either be occasional glitches, or there'll be SRC running
somewhere which will degrade the quality)
> Does anyone use there PDIF I/O from hardware into there Firewire interface? Is there an increase in performance? Does it effect tone? Do you use standard RCA cables?