There's something wrong with the onboard sound on the XE. I don't know what the details are. Apparently, finding a fix for it has been forgotten. I would like to see some work done to repair it - I'd much rather ditch my Soundblaster card and free up the PCI slot since I don't do heavy duty audio work.
Sound under Linux works fine with a soundcard on the XE, and the onboard sound of the MicroA1 is fully operational. Don't know which specific driver to use under Linux, but I'm sure it exists.