Protecting equipment from bad power.

[Bob Lee (QSC)]

Good call. I've attached a very short clip that captures it. You can hear the sound all over the female vocal. The mic is plugged straight into the board and has no effects on it. A similar sound tracks through with the guitars, but not my bass. The guitars are mic'ed, I direct line into the PA.

That's some weird distortion, not noise. Like a misadjusted effect on her vocal channel or something. A power "conditioner" or voltage regulator or whatever won't fix that.