gallaine: you say that you thought you had solved your sibilance problem but then it returned. what did you do, or perceive that you had done, to "solve" your problem? you have a complex system comprised of many parts. each of those parts "reacts" to every other in the chain. finding the weak link is no easy task, as well you know. i suspect the annoying sibilance emanates from the match or mismatch between your transport and dac. i would also suggest you have overly bright interconnects for your component, although you say you've tried changing them out. did you substitute copper interconnect between EVERY component, SIMULTANEOUSLY? if you didn't, i'd suggest you somehow arrange to do so. i empathize with you. sooner or later, we each hear a mouse in the works we can neither see nor capture. have patience and continue your quest. i'm sure you will eventually capture and tame the little beast. -kelly