This is a simple, but annoying case; I have a set of Bluetooth headphones that I use with my computer when I want to watch something late at night, or just to avoid disturbing anyone, and they work great. However, after I use them my Mac always defaults back to Digital Out as the audio device, even though I have never (ever) used this or chosen it in the audio panel in System Preferences.
Instead, I'd like it to just go back to the previous audio device, which is an external sound card (a Griffin Firewave Firewire device, though I may be replacing this with a USB alternative).
Is there a way to do this? I've recently discovered I can switch audio device by option-clicking on the volume control in the menubar, but it's still annoying that OS X goes back to a default that I've never used! Alternatively, is there a way that I can disable other audio devices such as internal speakers and digital out, so it can't pick them?