M-Audio Revolution 5.1 Daryna SPDIF and Headphones

[Husse]

How can I force the use of SPDIF in .asoundrc?

I've seen
pcm.!default spdif
or if that does not work
pcm.!default {
type hw
card 0
device 2
}
That config file tells ALSA to override using the default device, and instead makes 'hardware device 2' your default. That's probably going to be your SPDIF out but you may have to change it for your configuration.

[Husse]

Check settings - there may be something about spdif in the players
Admittedly this is complicated