Are my CAT5 and router my weak link?

I can confirm what Al has reported about my experiences when I replaced an unshielded Cat 5 cable with a shielded Cat 6 cable. The result was more resolution. A lot more.

The $7 shielded Cat 6 cable resulted in a bigger improvement in SQ than several $1,000 power cords and several $2,000 interconnects. Yes, I know that sounds crazy. I can't explain it.

I'm not saying that other systems will benefit similarly. In fact, I doubt it. But it's certainly an affordable experiment.

As far as the router goes, I too have a router indirectly connected to my audio system (outside line -> 15' shielded Cat 6 -> router -> 1' shielded Cat 6 -> ethernet switch #1 -> 20' shielded Cat 6 -> ethernet switch #2 -> Sonos -> audio system). Ethernet switch #2 is a bus between the computer and the Sonos. Ethernet switch #1 has only one function: to sever the connection between the router and the audio system...

The router is left on all the time. I have the PSU for ethernet switch #1 plugged into a rocker switch, which is itself plugged into the wall. When I listen to music, I flip the rocker switch to kill the power to ethernet switch #1, which kills the connection between the router and the audio system. Don't know if any of that is relevant to your setup, but it's another easy and affordable thing to try.

Bryon

If I understand it correctly Ethernet cable connects computer to wireless router. If that's the case then it is in some distance from the DAC that has built in wireless receiver eliminating capacitive coupling and leaving electromagnetic radiation to consider. This radiation is practically eliminated, not only by very tight (>2twists/cm) twist on CAT6 cable, but also the fact that signal is balanced. Radiation is limited to common mode noise coming from the system (perhaps power supplies). This noise (whatever the source is) has to be strong and at least 30MHz to make effective (1/10 wave) receiving antenna of typical 1m interconnect. At this frequency skin effect is very strong and interconnect's shield is working very well (Noise from crude computer switchers is in the frequency approx. 100kHz and has no chance to be received by 1m antenna). Of course it would be wise to keep this Ethernet CAT6 cable as short as possible and far from the DAC.

Think of it like this. Your data is transfered from a NAS into a buffer in the PWD Bridge. If you copy an excel file from a NAS to another node on the network, it will be bit for bit perfect (i.e. the exact same bits) all the time, irrespective of quality of your cable. The same applies to your music file. It gets tricky when timing information is involved - not the case here. The bridge is completely asynchronous.

Kijanki - Your expertise in this area far exceeds my own. There may be good technical reasons to doubt that an ethernet cable can affect sound quality. Nevertheless, the effect I heard when I replaced an unshielded Cat 5 with a shielded Cat 6 was, from my point of view, too obvious to be attributed to placebo.

When a listener reports an experience that challenges an accepted explanation, it raises the question of the reliability of the listener. But it also raises the question of the reliability of the explanation.

Bryon

Using wireless LAN connection (Wifi) provides the best solution for physically isolating sensitive audio playback gear from potentially noisy computer gear as an insurance policy for best results. I would recommend everyone use this approach to connect their computer gear to their stereos and rest easy at night.