2 different sound cards having the same S/PDIF specs, will they sound differently with the same dac?
AN ASUS XONAR ESSENCE STX VS A REALTEK HD ON A GIGABYTE MB, to make it clearer.
I am wondering.
In my opinion, no.
Some people will argue that jitter may come into play, but most modern DACs claim to combat this. I find a £20 sound card with spdif sounds identical to a £400 CD player playing the same music, or a squeezebox or a £25 Asda DVD player.
Just my opinion though, I'm sure someone will contradict that. Maybe my ears aren't golden enough, who knows?
Either way, don't trust anyone who utters the phrase "night and day"...
Although with your examples, I would still get the ASUS, it probably doesn't even need an external DAC.
*edit. Just spotted you have the ASUS and a vDac. Which voids the last sentence. But no, any spdif that outputs a bit-perfect signal should sound the same IMO.