Hello all,
On my Thinkpad x240, I am experiencing exactly the same bug as someone on the x230 [0], that is I get clearly audible background noise on headphone and speaker outputs unless I mute the Headphone/Speaker control or Master. In both cases, a Realtek ALC on a Thinkpad is involved.
I have attached the alsa-info.sh output. The problems occur with plain ALSA output, Jack or Pulse are not involved.
I have tried all suggestions mentioned in [0], and also tested all available ALC-related model= parameters to snd_hda_intel, but the issue persists.
Muting all mixers on all cards didn't change anything either. Other Thinkpad laptops with the ALC3232 codec are also affected by this bug, for example [1].
The bug makes the audio output unuseable for any serious purpose.
I would be very grateful if somebody could look into this (again?), and also assist as far as I can.
Thank you & Best regards -Jens.
-- [0]: http://mailman.alsa-project.org/pipermail/alsa-devel/2014-August/080039.html [1]: http://askubuntu.com/questions/541538/headphone-hiss-after-upgrade-to-14-10
PS. I'm sorry if this is not the correct place to report this, but the bug tracker linked on the ALSA project home page seems to be down.