Why are there discussions on the internet S/PDIF vs USB regarding sound quality if both transmit digital signal? Wouldn't be there literally no difference?
Let's take this example: https://www.reddit.com/r/audiophile/comments/8t17rj/dac_question_usb_or_spdif/
someone got upvoted for answering:
Optical gets you complete electrical isolation, however it is typically higher in jitter in comparison to SPDIF or USB in most designs.
Since when "electrical isolation" matters when transmitting digital signal? Cannot digital signal be verified and re-sent on the fly if any packet fail validation, like in the TCP protocol? If you have big enough buffer, you wouldn't even be aware that this happened. Why and how is there any technical difference between SPDIF and USB in terms of sound quality, even if not really perceivable by humans?