Seppo Erviälä's answer is right but not complete. As dma_k already noted,
man alsactl clearly states at the end that,
/var/lib/alsa/asound.state (or whatever file you specify with the -f
flag) is used to store current settings for
palacsinit appropriately noted that you can store config into your file with
alsactl --file ~/.config/asound.state store
and reload with
alsactl --file ~/.config/asound.state restore
This can be further improved with placing the second line, the restore command into a .desktop file.
You will need to run
sudo nano ~/.config/autostart/alsarestore.desktop, which will open nano text editor and create ~/.config/autostart/alsarestore.desktop file. ~/.config/autostart/ entries are used to autostart programs and services for specific user on startup/graphical login.
The contents of the .desktop file should be the following:
Exec=alsactl --file ~/.config/asound.state restore
Among other things, you could store your config in /etc/asound.state and symlink it to /var/lib/alsa/asound.state, but this one is more of a suggestion rather than tested solution