Hey, guys. I have a '65 BF Deluxe Reverb that sounds really sweet, mostly. Lately (I don't know how lately; I have just started noticing it) it's been going sort of "blattt" when I play the low E string on my guitar a bit hard. It happens on either channel, and my Strat and Les Paul both do it. Any idea what it might be? I am fairly familiar with tube amp circuits and I know how to work on one without killing myself.