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?

retiredaudioguy

If digital signal is an on or off signal (0/1), and transmission is bit perfect, how can noise (random intensity fluctuations on a continuous scale) enter a cable? Either transmission is bit perfect, then no possibility for any noise. Or it is not bit perfect with resultant noise. 

I could have been really contentious and asked if anyone has heard sonic differences between T568A and T568A wiring standards.

 

OOPS.  That should have been:

I could have been really contentious and asked if anyone has heard sonic differences between T568A and T568B wiring standards.

I replaced most ethernet cables with inakustik Premium (double shielded) Cat6 Ethernet cables for the digital chain.

The Dawn Tech effe01 Ethernet/Fiber Optic Isolator connects to a Sablon Audio 2020 Ethernet Cable to my Grimm MU1 / Mola Mola Tambaqui.

I think that the consensus is that the sonic differences are caused, not by digital issues, but by RFI or other noise induced in the patch cord leaking through into the analog circuitry.

Perhaps I am lucky (or hard of hearing) but yesterday I listened back to back to the Weilerstein Elgar from my Aurender SSD, USB connected to the Esoteric K-01XD SE and the same work streamed from Presto through the Bluesound Vault, TOSlinked to the DAC and detected no differences.  I live in the country, and my system is located far from any in-home electrical or electronic devices.  Also, the Esoteric unit is engineered to separate analog and digital processing.

My streaming is limited by drop-out in my internet connection.