Audio: Way to disable HDMI or set USB as default?

[nikolas]

Sorry for being slow, I was traveling and didn't find time to try a few things. The fix makes it rediscover the amp by itself and if I switch on the amp in time, it doesn't switch to HDMI. So that's great, but if I remember to switch on the amp when it reboots, I seem to do so within one minute, so I left it at the default of 1 min, I didn't try the longer wait times (but would be happy to if that's useful). But if the pi restarts unattended for some reason or I completely forget about the amp, then I think it still switches to HDMI and never goes back. So then I still have to switch output manually. I guess that's harder to fix and its much less of an issue now that things run pretty stable, i.e. the pi doesn't restart that frequently (mostly when a kid pulls the plug) and when it doesn't work, its almost always the output (so I remember and don't try random, stupid things first).

Thanks a lot for your help with this and please let me know if it would be useful if I try the other settings!