Axiom Home Page Forums General Discussion Technical Questions What does a "bad" digital coax cable sound like?

Okay, I read through that toslink thread and found this from Alan (who seems like he knows things):

"The only advantage of an optical digital (Toslink) connector is that it is totally immune to hum pickup from AC fields where a connector crosses an AC power supply cord. "

So Alan states that a digital signal transmitted along a coax CAN pick up artifacts/interference from AC fields that impact sound quality. This statement is counter to much of the other discussion that supports a binary view of sound quality over a digital coax line.

What am I missing/not getting? Can my long-run digital coax cable pick up hum from an AC cord (or other source of interference) or not?

I'm not trying to be ornery, it just comes naturally!