Toslink

I can't think of a mechanism for a volume change with optical cable change, no. Doesn't mean its totally impossible though.

A parallel question: IS there any appreciable audible differences between Toslink cables?

Volume changes seem doubtful but clarity is another story. Some of us have found enough difference between glass and plastic to stay with glass. Also, my Lifatec cables handle 24/192 while the Blue Jeans cable (which is nicely made BTW) can only go as high as 24/96. Same with other plastic ones I've tried.