Finding the best alternative to my Chromecast after having cancelled wi-fi plan

[steak]

For years, I streamed high quality audio to a pair of Adam AX8 amplified speakers using a Chromecast Audio with a jack - rca Y-cable plugged to it.

I recently cancelled my ADSL wi-fi subscription, because I didn't really need it and wanted to use my phone for everything Internet, including a hotspot when I need my laptop.

Without a home wi-fi, I can't use my Chromecast Audio without relatively complex workarounds such as using two phones (one acting as a router for both the other phone and the Chromecast dongle) or a travel router (same).

The remaining solutions are:
- Wired: As my phone does not have a jack, I need to use a USB-C - jack adapter and plug the male jack of the Y-cable to it
- Wireless: a bluetooth receiver such as Esinkin with either jack or rca output

I have a couple of questions:
- Is there likely a significant difference in sound quality between connecting to a phone via its jack or USB-C port?
- Is any wired solution superior to bluetooth, including a relatively basic/cheap USB-C - jack adapter?
- Does it make a significant difference if the bluetooth receiver outputs through jack or rca?

Thanks

 

[dunring]

The Apple 3.5mm to USB adapter sounds good, costs $9, and lots of power for headphones for such a tiny device. I use one for lots of things when not on my main system.