Constant metronome type ticking in deluxe reverb, blackstar stage 60 and 15 watt Marshall solid state. Happens with Tele, Strat, and. Charvel. Straight into amp with no pedals. Tried different cables.Had my wife turn off one breaker at a time but no change. Unplugged electric dog fence. Nothing. Could it be coming through electrical system from outside? Is there some type of filter that can be used between amp and wall plug? Come on gang. Help me!