Maybe this is a stupid question and it's out of curiosity more than a need. I often read that people could use a Y cable to "mix" the output of 2 analog soundcards. It is not recommended but it can work, there is some risk associated with this practice too.

Similarly, I wonder what would append if one would mix two PCM (not dolby digital) output signal. I am not very familiar with this protocol but I assume some sync is sent time to time to inform the receiver of the bit depth and rate. So let say they are the same.

On my setup I have a sblive and awe32 both connected to different digital rca input of an onkyo tx-8140 receiver. Now, what would append if I cross the line and put both cards output with a Y cable on one input of the receiver?

1. No sound or white noise.
2. Perfect and crystal clear mixing of two sources
3. Total flaming obliteration of my precious hardware

#1 is expected and #3 is why I dont try it. Any thought?