I have a B52 AT100 tri-rectifier amp and a matching 4x12 cab. I run my guitar into my GNX4 from there to a BBE 362 sonic maximizer from there into my effects return on my amp. Last night I was playing and I started hearing some periodic scratchy noise so I stopped playing and my amp still made the noise. Haven't been able to get it to do it again but what might cause this?