Have you played with the "Audio MIDI Setup" control panel? Do a command+spacebar to search for it.
If you getting it working, consider purchasing the "BitPerfect" app for $10. Really made the USB sound out of my MBPs much better.
Then once you are ready for more, consider a step up to a Roon Nucleus or other server. The sound was clearly better (lower noise floor) than two different MBPs+BitPerfect. Install and run Roon on your MBP first to see if you like it and if it is worth the money to you.
If you getting it working, consider purchasing the "BitPerfect" app for $10. Really made the USB sound out of my MBPs much better.
Then once you are ready for more, consider a step up to a Roon Nucleus or other server. The sound was clearly better (lower noise floor) than two different MBPs+BitPerfect. Install and run Roon on your MBP first to see if you like it and if it is worth the money to you.