@Vedrfolnir It's a linux x86-64 machine. It's not a problem really, I just quit cmus and relaunch it with a keyboard shortcut — the player is so minimalistic and fast that it literally takes as second. I just wonder, maybe there is a magic :reinit_sound_output command that I don't know of or something like that 😁
Most probably there isn't, cmus although modular, considering how fast and minimalistic it is, I think no one cared enough to make the output modules hot-pluggable.