happening for me too on my MacPro 5,1 with a Xonar HDAV1.3 Deluxe PCI-E sound card. going to get an RCA cable to see if i get sound like the rest of you. my box has 128GB memory so i don't think it's a memory issue. it is more likely something to do with the format parameters and an imprecise bytes-to-frames calculation. i know mine need tweaking for this SPIFFY PCI EXPRESS SOUND CARD ON MY MACINTOSH

this was my bad lol. the reason i can't hear anything is because the HDAV1.3 does not have any "powered" outputs. they are all passive (save the HDMI in/out and possibly the mic in). my bad fellas.

https://www.youtube.com/watch?v=2NCjEa_1YwU demonstration of functional headphone jack on the Xonar STX II pci express card. all around the world gotta spread the word tell em whatcha heard gonna make a better day

all around the world gotta spread the word tell em whatcha heard gonna make a better day