Lennart told me that it is a kernel bug for my sound card, and ALSA is supposed to not to expose the Headphone channel. Submitting to kernel bugzilla.
-- Headphone channel not affected by volume slider https://bugs.launchpad.net/bugs/429109 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
