sid - vlc - changing application-internal volume, above or below 100%, produces high level distortion

[Zenaan Harkness <zen@freedbms.net>]

I'm on sid, running vlc 2.1.4.

No pulseaudio installed. Just alsa.

By default, VLC sets its "internal" volume to 100%.

When I change that "application-internal" volume, either above or
below 100%, high level distortion is produced. Changing it back to
exactly 100%, normal sound resumes.

Any ideas what's going on here?
TIA
Zeanaan