At last night's gig several patches exhibited a phase-y swoosh. More noticeable on some patches than others. I had never experienced this before. I repeatedly checked to make sure no effect was inadvertently engaged, and no effect was the cause.
I was running main outs stereo to FOH with an unfamiliar sound guy, so I'm wondering if he did something weird. The seting did not allow an opportunity to trouble shoot.
Any ideas what might have caused this? Thanks!