How can different CAT5/6 cables affect sound.
While is is beyond doubt that analog cables affect sound quality and SPDIF, TOSlink and AES/EBU can effect SQ, depending on the buffering and clocking of the DAC, I am at a loss to find an explanation for how different CAT5 cables can affect the sound.
The signals over cat5 are transmitted using the TCP protocol. This protocol is error correcting, each packet contains a header with a checksum. If the receiver gets the same checksum then it acknowledges the packet. If no acknowledgement is received in the timeout interval the sender resends the packet. Packets may be received out of order and the receiver must correctly sequence the packets.
Thus, unless the cable is hopeless (in which case nothing works) the receiver has an exact copy of the data sent from the sender, AND there is NO timing information associated with TCP. The receiver must then be dependent on its internal clock for timing.
That is different with SPDIF, clocking data is included in the stream, that is why sources (e.g. high end Aurenders) have very accurate and low jitter OCXO clocks and can sound better then USB connections into DACs with less precise clocks.
Am I missing something as many people hear differences with different patch cords?
The AI Summary that Google is often quite useful in that it creates a summary of all the stuff that it has found online about the search terms. As a consequence the response must be contemplated critically, and the response is sometime head spinning in that adjacent sentences may state something and its negation. A fundamental principle of logic is, symbolically, ∀ A (~(A&~A)). Unfortunately today, critical thinking is, in medical terms, in a critical state. |
@unsound yes indeed it should! Thank you for the link, I hadn’t looked at it in I don’t know how long. Funny, this entry:
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help me understand how this comparison is relevant in a context of Ethernet cable discussion. How’s it even valid at all? |
I think it is relevant in that the streaming signal was received through a cheapo Cat 5 cable, an inexpensive streamer and plastic optical link, the other signal was USB from data stored on the Aurender. I believe that Presto's streaming service aims to provide the same quality of sound as their downloads. My thesis is that, with a truly well engineered DAC (e.g. The K-01XD with an external rubidium clock), how the digital data gets there is not relevant - given source gear that gets the correct data to the DAC, which all minimally competent equipment and cables do. Or, perhaps, Presto's MPEG4-SLS codec is more resilient than Qobuz's FLAC, I do not know. Or perhaps my hearing has gone. I have been researching the issues and the MPEG4-SLS codec will scale back the quality of the streamed data if there are bandwidth problems. Those problems could arise if the streaming device detects data errors and causes retransmissions to be necessary, and that could be caused by a poor Cat 5 cable. Remember my initial question was "how can Cat5/6 cables sound different?", I was not asserting that nobody actually hears a difference. I guess that the answer could be that the streaming service downgrades their transmission if there are too many data errors.
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