Hi Steve, A wierd quirk on my part, is I fuss over my K2's Filter settings. It took me about an hour, and a little home-brewed rock-solid signal source, but I am able to get all 4 filters so that I can not hear any shift at all in tone from one filter to the next. I know I'm a strange bird But hey, thats what turns me on :~] Duane N1BBR -- Bw_dw at fastmail.net