I had complained that I couldn't set the volume on a Pro Audio Spectrum card.
It turns out that is because it emulates a SoundBlaster 1, which had no mixer,
so the SB driver code treats it as a seriously deficient card.

I'm going to try to write a native PAS driver (using the Hannu Savolainen
driver from Linux/FreeBSD as "documentation") but I strongly suspect that
it will be easier to buy a new sound card...