Not sure why so many people get their panties bunched up
by what the OP is doing by re-purposing an old iPhone? I am using an old iPhone SE at the gym by streaming tidal or qubuz on their WiFi. Sounds like my old iPod shuffle but with WAY more music to pic from than iTunes playlists. I use my iPhone 7 in my bedroom as a streamer to a shiit DAC with a Realistic old receiver to power it up. It’s music guys, we are not building rockets for space travel. Just loosen up and enjoy what you have. If you are using a raspberry pi, vanilla wafer, or chocolate cookie and getting music to make you happy, isn’t that the why we listen? Cmon!