This might be in the wrong area,but: recently, I have noticed that when I play my low E string and it rings, I get a sound that sounds like I have a phaser effect on it. I use no pedals, and have no phaser effect in my rack. My signal chain is this (and hasn't changed in many years): either original Fender pups or 80's era EMG's --> Sans Amp RBI pre amp -->QSC Power amp --> Avatar B410 and "homemade" 2x15 with Emminence speakers I use Ernie Ball Super Slinky's 105-45. This phasing sound has only started happening in the past 6-8 months, and only when I play the E string and let it sustain. It happens worse at the practice palce than at gigs. Would this be something electrical? Is the pre or power amp starting to go?