Hey folks, Our church PA is slowly getting to the point where we can stop worrying about problems...slowly. The issue we are getting is a random, yet regular, buzz that goes through everything. Like...everything. Equipment list: Mackie DL1608 w/iPad2 Peavey SP mains and amp Phonic amps for monitors and sub Behringer passive floor wedges Samson Q7 mics Line 6 wireless system for lapel mic Shure wireless system for handheld Watching the meters on the iPad, I can see spikes in noise every so often even in muted channels. Only unplugged channels are free from it. Otherwise, it hits everything. Now, supposedly the building was wired so that all of our audio equipment (outlets in the booth and on stage) is on the same circuit, which I assmue means the same ground. This isn't a constant ground loop hum...just periodic buzzing, maybe a little higher than your typical 60Hz. Ideas?