Hi! I've got a little problem which seems to be general, for all my pedals. When I switch then on and off, I hear a little scratchy sound, like a slight buzzing. Having the same problem with 8 pedals at the same time makes me think it's not the switches. I do daisy chain a few of them (but not all of them). Could it be a problem with the adaptor I'm using or should I look elsewhere?