The only way you will know is to try, as the difference will depend on the quality of receivers in the DAC for various inputs. Such differences, in an ideally engineered DAC, will be small to none, typically far less than differences heard when moving your speakers by six inches or so.
While poor optical interfaces certainly exist, some users find that by using optical, transmission of noise between components is reduced. So, perhaps you can borrow an inexpensive SPDIF coax cable and listen for yourself.