Hi Max!
Avid Poweramp user here since my first Android phone, Xperia X10.
1. Samsung Galaxy S i9000
2. Custom Rom 4.4.2 SuperNexus 4.0 (Voodoo Sound)
3. Its has a Wolfson WM8994 https://www.cirrus.com/en/pubs/proDatasheet/WM8994_v4.4.pdf
For me, and to all people who are still using it as their music player, its still the best sounding Android phone to date. Enabling Hi-Res audio will make it even better.