The results are little odd but at least this is a plausible workaround. Doing a store as you suggest (thank you for that, BTW
) does write my (changed) settings to /etc/asound.store but taking down and restarting KDE shows that the mixer doesn't automagically pick the settings up (so where are they coming from, I wonder...). alsactl restore does bring my settings back, however, so there is
at least some hope of avoiding resetting everything by hand every time I restart the system. But KDE sure doesn't seem to want to remember what I did. Feh...!