Dang, I thought he had built his own hardware.

I'd still love to get a proper successor to the Sandisk Sansa Fuze, just with USB-C charging instead of its proprietary charging cable.

There's plenty of "luxury" /audiophile MP3 players out there which cost in the hundreds of dollars, but that one was in the sweet spot of bang-for-your-buck music player that I could just use for listening to music on long plane rides etc. without draining my smartphone battery.

I get what you're thinking of with having a separate device, but I've found it better to just have a decent extra battery pack to travel with. You get a lot more flexibility with use. Maybe you just wanted to listen to music. Maybe you later decided you actually wanted to read instead, or play a game, or watch a video. Maybe you forgot to sync those podcasts until you got to the airport waiting on the plane and only just downloaded it and now it's a hassle to bust out a cable and sync it to your offline only MP3 player.

Essentially, you could carry a small battery attached to an extra sigle-task dedicated device, or a slightly larger battery in about the same-ish form factor that will let you use that energy to do anything you want with your other device you're probably already carrying.

If your phone is in whatever airplane mode, battery saver mode, etc. it's not going to use that much power just to play local music.

I had been wanting something similar recently and ended up buying a Hifi Walker H2 and loading rockbox on it. Works great, and it’s a total nostalgia trip to be using rockbox again after so many years!

Wheels will always be the best way to navigate music libraries.

You have many options for DAP, unfortunately they are often android based. In some rare cases, they are either pure custom OS, or stripped down android device. I have a Cayin N3U, I hesitated a lot with some Hobby device as it's a small brick and Android, while the android interface is still too present for my taste, and a bit too large, I have no regret, I really wanted something dedicated, no Bluetooth, tube, portable, no streaming, no extra app.

I wonder if you could get an iPod Classic and upgrade the storage/replace the battery...

I've considered building a device with the Teensy.

I don't even need it to be portable. In fact, I'm happy with a "component stereo" look with a VFD display. ;-)

The Tangara from cooltech.zone fits most of ur requirements, except the price one maybe