I recently picked up an old LG V30 to use as a dedicated audio player. It’s got a great headphone jack, it’s got a micro-SD slot, and there’s a build of Lineage OS for it too. It’s been nice, I can use some pretty power hungry headphones with it without issues and having a dedicated device for music has been nice for focusing on the music.
Mine is just the cover for Bitte Orca by Dirty Projectors