USB DAC/amps are less impressive on Android Spotify because the standard Android driver is up-sampling. The Dragonfly Red runs at 44.1kHz with Spotify on my PC but on Android it up-samples to 96kHz causing glitching. Other DACs have similar issues. The proposal is for Spotify to access USB DACs directly, bypassing the Android driver.
Audiophile music players already take this approach, e.g. USB Audio Player PRO (UAPP) and Neutron. Tidal works with UAPP.
This idea is a version of "Support USB Audio through the USB Audio Player PRO driver" without the 3rd party partnership. It was written in response to @meahtenoha's review. Both ideas originate from the USB audio out OTG support thread.
External USB headphone DAC/amps for Android phones are becoming a thing. What Hi-Fi has a Best DACs page that mainly lists portable audiophile kit. I would prefer to carry a phone and a DAC rather than a phone and a portable music player because it is more fun to have access to the whole Spotify catalogue.
Updated on 2019-09-18
Thanks for coming to the Community, and adding your vote to this idea!
We're setting this idea to 'Not Right Now', as this isn't something we have any immediate plans to implement. We appreciate you sharing your thoughts.
If we do have any new info to share, rest assured we'll check back in here with a new status.