I recently received my second B&K REF 50 (the first was defective - the volume control did not work). The volume control works fine on the new unit, however, the front 3 channels emit a high pitched noise. You can hear it from the front right and left channels when you place your ear to the tweeter. However, you can hear it from the center channel from several feet away. The center channel speaker has higher sensitivity than the other 2 channels. I called B&K today and they stated that this is not unusual and is the result of processor noise. I've never heard of this before and when I inquired further they represented that their units do not include mute circuits, unlike other manufacturers. The lack of mute circuitry makes the processor noise audible. Does this make sense? Can any other B&K REF 50 owners hear this processor noise from their speakers? The sound is somewhat annoying and I am considering returning the processor for a different brand/model. Thanks.