フォーラムにこのように書いてありました。
このalpha版をインストールすると、バージョン2の現行最新版にロールバックするにはアンインストールする必要がありますので、設定を保存してから行ってくださいね。

Poweramp alpha3 build-703
Google Play testing Opt-in URL: https://play.google.com/apps/testing/com.maxmpz.audioplayer 
(Use this URL again for Opt-out if needed.)

This is alpha version of upcoming major Poweramp release. Please make backup of your existing Poweramp app/settings/db before installation as you won't be able to rollback to Poweramp v2 without alpha uninstallation, causing settings to be lost.

You can install it over your existing v2 or any alpha version (your purchase and settings will be carried over).
At this time, only ARM processors are supported. We'll add Intel support for later beta builds.
Min. supported Android: 4.1.
Skins are disabled in alpha as UI is partially changed and there is no point in (re-)building skins now.

Alpha-3:
- added DVC support for Hi-Res Snapdragon 24-bit PCM variant (e.g. LG Gx/v10, HTC A9, etc.)
- Hi-Res support for Sony Z3, Meizu 5 Pro, Lenovo Vibe X3
- Look and Feel / Status Bar/Notification / Notification Colors option to override non-standard ROM notification colors
- mp3 vbr seeking improvements
- 2 Hi-Res API variants (Sony Hi Res and Snapdragon 24-bit offload) for Sony Z5/P
- option to always process/send album art (useful for smartwatches)
- bt pause/resume polishing
- scrobbling fixes, removed obsolete ScrobbleDroid support
- album art downloading update
- language selection fix
- better current output device detection (wired headset vs bt)
- other few small fixes