Originally Posted by Dr. Strangelove
In any case, you must remember that the USB cable and connector was designed for transmission of computer related data, not a digital audio signal. Not saying that it's bad at passing digital audio, just saying that it was not designed with it solely in mind like coax and optical were.
Sorry, I don't mean to be rude......but just what point are you trying to make?
Data is data, regardless of whether it is audio data, a spreadsheet, a web page, whatever. If the system transfers it without error and within the time constraints required for the downstream device to process it optimally, what difference could there be? Your hard drive doesn't know that FLAC or mp3 file is music and treat the bits more tenderly, does it?
Coaxial cable was around for decades, transmitting ultra high frequency analog signals before digital audio came along.....and most RCA plugs are not ooptimally designed
for digital transmission. Back in the mid-70's, when LED's were first produced in commercial quantities, it didn't take long for systems to be developed that used LED's and fiber optics to transfer analog audio signals to avoid RFI/EMI in radio stations, for instance. Neither coax cable nor fiber optic were designed specifically for digital audio.