What am I doing wrong?

Interesting that you are currently using your phone but indicate it causes "high pitched change" to the sound quality.  But then you say you don't want to use a DAP because it looks too much like a phone. 

One other thought -- you could try a Raspberry Pi with the Raspberry Pi or pCP OS and enable the LMS (server) program. This would allow you to plug in external storage devices (USB A inputs) which could be managed with a browser program on your PC, laptop, tablet or phone. You'd still need an adaptor for SD cards. And you'd probably also need a bluetooth dongle for that feature.  You'd need to do some research to make sure it does everything you want and then more setup work than for a preconfigured device, but you could customize it as much as you want.  

If that doesn't work for you then I'm out of ideas. Not sure there is anything out there that does what you want out of the box other than a DAP device which you've indicated you don't like for cosmetic reasons. 

Good luck! 

Thank you for your help, the Raspberry pi Option is an interesting one and I will look at that with pleasure.

My reservations about a DAP simply stem from my belief in it's capability to monitor itself. I think it will be likewise a phone with the inherent battery problems and therefore with a clock misalignment. Not noticeable with headphones, but with large speakers.

As respects a DAP, perhaps order one from an online retailer with a full money-back return policy.  If it works, problem solved! If it doesn't send it back for a refund. 

Thank you Amazon!

I have an Innuos Pulsar Streamer and Accuphase DC-1000 DAC and as incredible these components are, they are useless when the internet is down since my only source for music is streaming. After extensive research I've been contemplating creating a curated library of  local files to get me by when the internet is down. Basically purchase the hi-res file from Qobuz, ECM etc from my Samsung Gallaxy Ultra,  then transfer the file to a WD Red SN700 2TB that's inserted into a Sabrent EC-SNVE, and then connect the device via USB into my Innuos Pulsar.  The Sense App for my streamer then detects my local files and so basically I'll then have music.