Comment 10 for bug 1498129

What needs to be done to unexpire this? I have exactly the same problem. Like the OP I have confirmed that aplay plays fine to the iec958 device but pulseaudio seems to alias it's iec958 oputput to analog. I also have a colleague with the same card so this bug affects at least 3 of us. My card is the Xonar U7 Echelon Edition which I believe is exactly the same card as the OP, just different packaging and curiously a different alsa-name: Xonar U7 Echelon Ed.

I don't really understand alsa/pulseaudio config etc but happy to product/hack config files etc. to test any ideas.

Since aplay to hw:3,1 worked for me I wondered if Raymond's comment about iec958 needing to be first device was the problem and simply tried editing my USB-Audio.conf to be :

# If a device does not use the first PCM device for digital data, the device
# number for the iec958 device can be changed here.
USB-Audio.pcm.iec958_device {
 # "NoiseBlaster 3000" 42
        "Xonar U7 Echelon Ed." 1

This made no difference (but then I did say I don't understand alsa/pulseaudio so was probably stupid)