Old phone which is supported by (even an old version of) LineageOS, kept permanently in airplane mode.
Can be extra cheap in countries which have switched off 2G+3G networks, and old phones are more likely to have a headphone jack. You might even have one kicking around in a drawer.
Audio output quality and headphone driving capability varies – research on audio forums for what might be good. LG v-series were very good.
If you’re feeling adventurous you could crack it open and remove/short antennas & microphones and cameras.
If it’s usb-only or the audio section is poor quality, apple sell a cheap usb-c dac that’s pretty good. (get it from a reputable source – most are counterfeit).













Last night:



May 2024 was better:
April 2023:
…all from Melbourne’s far outer west, using an old sony nex camera. Did my best to preserve it as perceived by my eyes. No enhancement or turning up the colour (like phones and some cameras do now with their baked-in AI enhancement).