Master Channel has no Effect on the Sound Card

If the Master channel has no effect on the sound card, then the default control has to be switched. Use gnome-alsamixer or alsamixer to test. GNOME does not provide a means to switch default mixer controls, so here is how to switch the mixer(s) affected by a multimedia key although the volume bar (screenshot attached) will stop appearing:

  1. Open the Trisquel menu.
  2. Pick System Settings.
  3. Go to Keyboard.
  4. Switch to the other tab: Shortcuts.
  5. Click Custom Shortcuts.
  6. Click the plus button.
  7. Give the shortcut a name like "PCM up".
  8. Enter a command, like "amixer set PCM 1+". This will raise the volume as much as alsamixer would after pressing the up arrow key. 2+ is also suitable, but 5+ is probably too much.
  9. Apply.
  10. Click Disabled.
  11. Use the multimedia key as though it would increase the volume.
  12. Press Reassign.
  13. Repeat steps 6 through 12 for the "PCM down" shortcut, but use a minus instead of a plus symbol in step 8, i.e., amixer set PCM 1-
  14. For another control like Headphone, repeat these steps, but hold down the Ctrl key while using the multimedia key.

Revisions

02/21/2014 - 19:16
antiesnob
04/14/2014 - 02:51
alguien
09/06/2014 - 21:59
muhammed