Apparently it's not just us, this is an upstream change. Dave Jones found this: https://www.raspberrypi.org/blog/latest-raspberry-pi-os- update-may-2020/
To select headphones, the recommended process is now to create a file called .asoundrc in your home dir with these contents: defaults.pcm.card 1 defaults.ctl.card 1 ** Changed in: linux-raspi (Ubuntu Focal) Status: New => Invalid -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-raspi in Ubuntu. https://bugs.launchpad.net/bugs/1889468 Title: 20.04.1 selecting audio output device does not work on rpi Status in linux-raspi package in Ubuntu: Invalid Status in linux-raspi source package in Focal: Invalid Bug description: Testing the 20.04.1 candidate images on rpi (currently rpi4-2GB) I'm noticing that I can no longer select the audio output device with amixer. This used to be possible by using: amixer cset numid=3 2 for HDMI0 amixer cset numid=3 3 for HDMI1 amixer cset numid=3 1 for 3.5mm headphone jack However, now trying to set this gets the following error: amixer: Cannot find the given element from control default It seems that by default, it will now use the hdmi output for whichever one is connected, and will only output through the headphones if no hdmi device is connected. Kernel is: Linux ubuntu 5.4.0-1015-raspi #15-Ubuntu SMP Fri Jul 10 05:34:24 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-raspi/+bug/1889468/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp