Reading up on the "Edge" 5E3 Deluxe I saw mention of an RFI Cap being added in the vicinity of the PT to reduce power line noise. Can anyone explain where its installed, why it would be needed and generally how it works? Is it like an EMI suppression filter? This is a new one on me. I read this paper and it while a lot of it was over my head, some of it was interesting. But I don't get the impression that it was exactly on point with what Fender is doing inside that amp.