No mixer after FreeBSD 5.4 install

[hufe at mail.eecis.udel.edu]

We just upgraded from 4.9 to 5.4. After the upgrade, we no longer have a
mixer. That is, if I run mixer, with no arguments, I get:

$ /usr/sbin/mixer
mixer: /dev/mixer: No such file or directory

Similarly, I get the following:

$ cat getsmart.au > /dev/dsp
cannot create /dev/dsp: Operation not supported

I think that should work, no?

Can anybody point me in the right direction?

Thanks.

- Mark