I'm guessing the impedance is wrong between my Bose QC-15 and the K3, I can't use more than 15 degrees of AF rotation or it blasts my ears unsafely. Any suggestion of a nice plug in stereo attenuator? I use a stereo adapter to run from the Bose stereo mini plug into the K#'s 1/4" stereo plug. Thanks, Gary KA1J