I have a brand new Jackson JS30, and I am already having issues with a weird fluttering sound when I pull of from 15 to 14, 9 to 8, 8 to 7, etc. I can't seem to find anyone else with this problem, yet I have had this same problem on three guitars. I have tried it on multiple amps, and with different cords, as well as taking it to the shop multiple times. Here is a link to the sound. "https://soundcloud.com/porter-larson/fret-fluttering/s-p9y5f"