CDM,
Take a look at this when you get a chance. There seems to be agreement that an effective USB cable must have an impedance of 90 Ohms. They indicate comments made by Gordon Rankin who founded Wavelength Audio and help design the Ayre QB9.
http://www.computeraudiophile.com/f8-general-forum/gordon-rankin-says-im-wrong-about-universal-seria...
Take a look at this when you get a chance. There seems to be agreement that an effective USB cable must have an impedance of 90 Ohms. They indicate comments made by Gordon Rankin who founded Wavelength Audio and help design the Ayre QB9.
http://www.computeraudiophile.com/f8-general-forum/gordon-rankin-says-im-wrong-about-universal-seria...