Control audio output between Line Out and Headphones

Hi, I'm struggling to configure the audio output of my Fedora 25 installation. I'd like to find a way to easily switch between front audio (headphones) and line out in Gnome Shell without physically plugging/unplugging any jacks. So to clarify my setup is as followed (on ASUS PRIME B350-PLUS Mainboard with Realtek ALC887 Audio Codec): * Headphones connected to the front headphone jack of my case via internal mainboard header * Amplifier connected to green jack on the mainboards backpanel When both, amp and headphones, are connected, the sound is only played via headphones. In the Gnome audio settings the the line out output device disappears and there is only the headphones output device. Then I used alsamixer so change "Auto-Mute Mode" from [Enabled] to [Disabled]. This way sound is played via amp and headphones simultaneously. Gnome audio settings still shows only the headphones as output device. I can than change Volume of "Headphones" and "Front" via alsamixer separately to get any mute/unmute combination I want but obviously this is neither comfortable nor compatible with any gnome extensions that would let me change output easily (like https://extensions.gnome.org/extension/906/sound-output-device-chooser/) I generated more Information with the alsa-info.sh script which can be found here: http://www.alsa-project.org/db/?f=9c9fd41a57760353f5989f85ae5b8e9185d1c2f6 Any Ideas? Thanks DK