http://circuitco.com/support/index.php?title=BeagleBone#Image_Files
http://beagleboardtoys.info/index.php?title=BeagleBone_Audio
Gerald
I checked the circuitco website, of course. But my question was about the files for the Ubuntu release, not angstom.
I noticed that the //lib/firmware directory for quantal contains several .dtbo files for various capes, just not the one I need for the audio cape. The older precise release supported the audio cape just fine, but the firmware setup has been reorganized in the newer release.
Use the "--uboot bone" to install the older v3.2.x based kernel. 
The v3.8.x branch is still in progress...
Regards,
Thanks!