> I assume you are using PulseAudio and Gnome. On my desktop I've seen > that sometimes some volumes get set to a low value that Gnome control > panel can't seem to restore.
Thanks Tomaz, I did get the volume up to its usual level (I believe) by going to alsamixer. I had tried this before but had not manually selected the relevant sound card (device), which apparently is not "default", having done so I was able to raise the volume again. I will check out your commands though to see if I can get an even higher volume. thanks again,