OK my freebies. Unplug analog power supply when listening to Cd and visa versa. Clean all contacts once a month. Wire management makes a difference. No wire should touch OR cross another. Elevate all cables off floor, racks, Keep powercords away from signal carrying cables. Keep IC away from internal wall wiring at least 6 inches min. Suspend speaker cables off floor with bakers string.
Move your listening chair back and foward to achieve a sweet spot. Sit more than four feet from rear wall.
Clean your room, no clutter. Eliminate first and second wall reflections. Do not forget the clg midway between your chair and speakers.
Be in a good frame of mind for listening. If not do something else. Turn every light off. Enjoy !
charles