I have some rather annoying very high frequency overtones that occur on one of my Strat's high E string...up and down the whole neck. Its a Fender Amer Std. circa 1989-ish; a very bright guitar with weak pups. I currently have a brass block and brass saddles and even a brass nut installed on it, but Im pretty sure this issue was there prior to the changes. I dont really hear it on any other guitars. The overtones do not occur on the same note played on different strings. Anybody have experience with this? Ive tried changing pup heights. Its even there when played unplugged though. Ill switch the saddles when I get around to it I guess.