[George Prentice]

I just upgraded my Olympica’s to Amati Traditional about a week ago. They never sounded harsh in any way. I have found them to be good sounding if a bit polite in the bass at the start... but I am very familiar with the sound that you describe. I have heard it with some electronics. The Amati are more sensitive in the high frequency than many previous Sonus. They are very fast... more like ribbons, so if there is high frequency hash coming through the signal path, you are going to hear it. While I am not a fan of Mac equipment, this is not a characteristic of it. So, I would doubt the Mac has the kind of infrasonic hash you are talking about, unless there is something wrong with it... like the bias set too high in the amp. I would look upstream. This problem sounds way more than cabling. In addition, while this would not be the cause.. how lively is the room? Reflective surfaces everywhere? Dampen behind speakers, side walls, and floors if wood. Also behind listener if reflective. You can see my associated equipment below. 300 watts, is plenty. My amp never breaks a sweat (as in kicks in class B at 150 watts used).