Is this workable?

[Sound22Card]

This is my 'system' right now: digital music on thumbdrives, ...some high-res, wav and flac, ....connected to Android phone through an OTG (through mini USB port where it is also charged). From the headphone jack on the phone (signal now is analog), to the RCA inputs on an older receiver, to speakers.
The sound is fine and the phone works well for selecting music files.

Now, ...what I want to do is try to still use the phone as a GUI to pick music files, but I want to upgrade the DAC from the phone to a separate unit with a better algorithm. Is there any way to have the new DAC unit take over the conversion job from the phone? I've heard that using the charging port on the phone to get the audio out ...is a good way to bypass the phone's DAC, but I am already using that port to input the music from the thumbdrive.
I have a Steinberg UR12 just hanging around. Is there any way to use this?
My additional problem is that the lower cost DAC's don't have a screen to use to select files, if I eliminate the phone from the system.
Any ideas on this? I'm not aiming high, ....I just want to improve a bit from what I currently have.

 

[majingotan]

Use a micro usb to USB-A female OTG cable. From there, connect your male USB A to USB B cable and ensure that you also have a 5V wall wart to micro usb to power your UR12. The phone with OTG cable handshake completed will send digital data only to your UR12. Just turn up the volume to max and control the volume through the UR12 output knob and you're good to go

 

[HemiRick]

My suggestion would be to get a Raspberry pi 3+ and an Allo Boss Dac (about $125) and install Moode audio on the Pi. The Pi can read your music off the drives, and you can control the Pi/DAC/Moode w your phone. The Allo Dac then analog out to the stereo.

 

[Sound22Card]

OK, majingtan,
I'm not quite getting this. I can maybe see this working if I had my music IN my phone, but I have it on thumbdrives, which can't be connected because I'd already be using the phone's micro-USB. Also, I thought the USB-B on the UR12 was only for powering the unit.

 

[Sound22Card]

How would a Dragonfly fit into my system: thumbdrive with music on it...to phone via micro USB......phone 3.5mm out to receiver to speakers.
What would I use to select the different files on the thumbdrive?

 

[AnalogSteph]

OK, majingtan,
I'm not quite getting this. I can maybe see this working if I had my music IN my phone, but I have it on thumbdrives, which can't be connected because I'd already be using the phone's micro-USB. Also, I thought the USB-B on the UR12 was only for powering the unit.

It's the other way round - the Micro-B carries power only, the USB connection is on the B. If anyone is going to use just one connector, you'd want it to be the more robust one.

Using USB storage is a bit of a complication, but you could try using a USB hub. Doesn't necessarily work too well (some USB audio devices insist on being on a root hub) but is worth a shot. Using a powered hub would probably be best, then you would connect a power supply there and feed the UR12 like that.

Or you could - gasp! - use a computing device with more than just one USB port.

 

[Jmudrick]

Seems a bit over the top complicated. For about $200 you can get an LG V30 and a 400GB SD card with no need to change anything.