How can different CAT5/6 cables affect sound.

On the issue of networks and their impact on sound quality. Those approaching this from the science perspective, prima facie argument precludes yielding any validity to those reporting networks do indeed impact sound quality. Ignoring this and reverting to prima facie arguments is not good science. Quality scientific inquiry requires addressing  this counter argument through development of more rigorous research into the possible causes for this variability. Simply writing off this evidence as some derangement syndrome, based on emotions and/or distrust of human senses doesn't pass muster. 

Instead of retreating to the same old refrains, try to find explanations for why individuals hear differences with a multitude of audio streaming devices. Another option is to actually experience these devices in your own streaming chain.

Instead of retreating to the same old refrains, try to find explanations for why individuals hear differences with a multitude of audio streaming devices.

@sns 

In many instances, those differences are heard in systems that are not galvanically isolated behind at least one run of SFP fiber.

When differences are still heard with components or cables located upstream of fiber isolation, explanations still exist for that phenomenon, to the extent that psychology is indeed a science.

Galvanic isolation in quality streaming components is virtually a given these days, certainly there are generic streaming components lacking this, and I do agree this needs to be addressed.

You're correct that TCP/IP ensures error-free data transmission, so theoretically, CAT5/6 cables shouldn't affect sound quality. However, some argue that differences in noise, shielding, or EMI from cables could influence the DAC's analog output stage or power supply, potentially causing subtle audible changes—though this isn't strictly about the digital data itself. It's a debated topic, with some attributing perceived differences to placebo or system-specific interactions rather than the protocol itself.

 

Just checked the web and this is the 18,456th forum thread about this topic with 352,789 responses not including this one

somewhere around the 15th thread everything that could possibly said about this topic had already been said multiple times

hard to believe you all  are debating it for the 18,457th time. 

here is a response to the same topic in last week's Weekly Recap. You can up the numbers by a bit.

I spend about 5 minutes a week here hoping for something interesting but you guys debate this same topic over and over and over and the same responses are repeated over and over and over. .If you search "Ethernet" in this forum you get 12,599 hits as of a few minutes ago. Everything that can be said has been said in those posts. Let's move on