Thanks for responding. With Henrik's help I found my config file.
I see in your conf file you do not define anything. That is
what I had by default and I got sound before upgrading my
system. Using mpv -ao help I see that I have options pulse,
alsa, oss and others. I tried invoking mpv with the
options --ao=pulse (when pulseaudio was running) and got
no sound. Then, again when pulseaudio was running I tried
--ao=alsa, again no sound. Finally I tried --ao=oss, again no luck.
Then I stopped pulseaudio and repeated the three command line
options --ao=xxx, and again no sound. While pulseaudio was
running I brought up alsamixer and set the sound card to
my NVidia card. Then I ran alsactl store to save the setting.
All of the following experiments were run with pulseaudio off.
Still working with the command line I tried --ao=alsa:device=plughw=1.3
and mpv didn't start. I tried putting "" around the device stuff but
mpv still wouldn't start.
Then I tried putting the audio device setting in the config file.
Here is my command line:
mpv -fs --vo=gpu --vd-lavc-threads=4
MOVIE.NAME
In the config file I tried:
audio-device=alsa/default which had been commented out.
and then
audio-device=alsa:device=plughw=1.3
again neither of these resulted in sound.
mplayer seems to work regardless of whether pulseaudio is running.
I ran through all these options exactly as written while writing
this response. Nothing works.