Hi Brian,
The issue is present in safemode. I have also tried a factory reset. My testing process has been
1. Boot up phone and follow set up
2. First app installed - spotify or soundcloud for consistent audio playback
3. Phone starts off fine but after playing a song for 20 seconds, crackling starts.
4. Crackling present throughout android usage including the tap sounds when navigating menus
Reboot phone - crackling disappears until step 3.
Safe mode - crackling disappears until step 3.
Connecting and disconnecting audio jack headphones also temporarily stops the crackling until speaker is used again
It's consistently replicable.