Many thanks for the fast response!
I can confirm that my current version is 0.2.0(153) and I am still noticing the audio issue.
The problem is a general issue with all audio, not just a specific file. It sounds as if the boosted audio is overloading the Oculus Go's speakers (but turning the volume down doesn't seem to help).
I have uploaded a short video example where the problem is obvious:
You can clearly hear the distortion beginning around 1.06 (in the music) but as I say, I am hearing this sort of thing with every other file as well.
This audio issue started with version 0.2.0; everything was fine with earlier versions of Skybox. The audio is also fine when I play files using the "Pigasus" media player (sorry to mention the competition!) but the video quality is much better in Skybox - especially with side-by-side 3D - so your player remains my preferred option.
Is there any chance you could add an option to disable the audio boost in the settings? I find Skybox the perfect Oculus Go media player in every other respect!