toslink vs coax for sound card out

[net-david]

I know (or I think I know) that coax is generally considered superior to Toslink for spdif connections. But when using an external dac with a pc sound card, would the electrical isolation of the optical connection be preffered?

Thanks,
David

[ashok]

I think this might depend on the interface at the input of the DAC.
If the DAC input ( or even the Sound card output) has a coupling transformer , I guess it should be fine. The two circuits should be electrically isolated. Sometimes however you have some resistors or caps going to the cahssis which might (?) compromise the situation.
Can anyone with more experience using these transformers comment on this issue?
Cheers.