I am prepping for my first gig with the above mixer. One issue..... I am using a harmonica holder mounted to the mic stand boom that positions the harp in front of the vocal mic. When I change harps, I mute the channel so as not to hear “clunks”. When I do that, the mic is muted, but I still hear “reverb noise”. ( am using reverb on that channel). My question is how is that noise coming through when the mic is muted?