Switching between active soundcards?
 

I have both a SB Live! soundcard and Lyra Wireless system installed on my Fedora 2 system.
I use the SB Live! for my computer speakers, and I use the Lyra system for transmitting sound to my living room amplifier.
If I boot up with the Lyra Wireless transmitter powered on, then the Lyra (driver) is active.
If I boot up with the Lyra Wireless powered off, then Linux defaults to the SB driver (snd-emu10k1), and the Lyra is inactive. How can I switch to the Lyra soundcard driver while I'm up and running? I can go to Hardware Browser and see both devices listed in "Sound cards", but where do I go to choose which device is active?