Digital signal that traverses via USB is encapsulated in an anslog signal and is represented as voltage fluctuations. USB is made of some sort of alloy, be it copper or silver, the only method to exchange data is voltage fluctuations.
Just recieved a sense check from an ex Sony colleague who was involved in the development of the Sony SCD1 at Kita Kanto, he now lives near Kosai and is retired but still as sharp as a tack!
"Hi G San
The poster is confusing the physical layer of USB with the audio domain. Yes, USB uses voltage transitions to represent 1s and 0s but that does not make the audio signal analog and it does not give the cable the ability to change tone, detail, warmth, air, or anything else.
As you correctly pointed out in your email G san, Voltage transitions carry data, not music. The DAC does not reconstruct audio from the shape of the voltage waveform on the USB cable. It reconstructs audio from decoded packets after error checking, buffering, packet reassembly, reclocking, jitter isolation and power isolation.
The USB cable never carries a continuous audio waveform. It carries encoded packets. So when someone says USB is analog because it uses voltage fluctuations, they are making the same mistake as saying a hard drive is analog because the bits are stored as magnetic polarity".................
So all that's left to negatively upset the apple cart is Noise, that is easily solved by shielding most decently made still inexpensive cables do this more than adequately, some double or triple shield, recognizing external noise as the only real influence.

