Shielded vs. unshielded Ethernet and Grounding

[Darryl R]

My dCS Network Bridge is connected to my DAC with dual AES interconnect, and connected to my music server via shielded Ethernet cable.  The music server is in turn connected to my LAN with the same shielded cable.  A reputable manufacturer advised me my system may grounded to the LAN because of the shielding on the Ethernet cable.  I have some occasional light humming in the speakers.

 

Has anyone experienced any grounding issues with shielded Ethernet?  I see it is a known issue in various on-line sources.

[Darryl R]

Thanks for the great reply AMP.  I'd like to take this up privately with you.

[Darryl R]

Thanks for this.  There seems to be a consensus among cable manufacturers with a sense of responsibility for their products that if shielding is used it should be grounded only at the source end.

[Darryl R]

On 8/1/2018 at 5:03 PM, jabbr said:

For the final connection between your wall socket to your DAC or streamer by all means use Cat 6 U/UTP patch cables and you won't have a ground loop.

 

For a new installation in your walls, I recommend Cat 6a either F/FTP or U/FTP ... the reason the shields are needed around individual twisted pairs is to reduce cross talk which is helpful at 10 Gbe ... now if the receiving device has a socket which doesn't connect ground then not an issue for ground loops. Audio doesn't need 10 Gbe but a short segment of Cat 6 is fine etc.

 

Personally I have Belden U/UTP 5e in my walls but have added LC-LC fiber.

 

If you are having a need for heavy duty shielding around your twisted pair cables there is another problem going on that you should first solve. Perhaps your listening room is sitting atop a high powered radar array?

 

You may have hit on something, I hadn't considered the phased array RADAR of the surface-to-air missile battery next door

[Darryl R]

Thought I'd post a response from Audioquest in connection with the main subject of this thread:

 

"Just like with our analog interconnects, we connect the shield at the receiving end of the cable only.  All cables are going to carry some noise, and we feel strongly that it’s better to ground the cable rather than have the noise floating around.  In our listening tests, both analog and digital cables sound better this way.  Please bear in mind that those cables that feature NDS (Noise Dissipation System), like Vodka RJ/E, dissipate the vast majority of the noise so there is very little being dumped into the component’s ground plane.

 

There is an easy (and cheap!) way of checking this out – you could buy an unshielded Ethernet cable for a few dollars and compare it to your Vodka.  It’s not just the superior conductors and insulation that makes Vodka better! In the unlikely event that an unshielded cable does offer improved performance in your system, we could always re-terminate your cable without the drain wire attached."

[Darryl R]

On 8/7/2018 at 12:49 PM, Darryl R said:

Thought I'd post a response from Audioquest in connection with the main subject of this thread:

 

"Just like with our analog interconnects, we connect the shield at the receiving end of the cable only.  All cables are going to carry some noise, and we feel strongly that it’s better to ground the cable rather than have the noise floating around.  In our listening tests, both analog and digital cables sound better this way.  Please bear in mind that those cables that feature NDS (Noise Dissipation System), like Vodka RJ/E, dissipate the vast majority of the noise so there is very little being dumped into the component’s ground plane.

 

There is an easy (and cheap!) way of checking this out – you could buy an unshielded Ethernet cable for a few dollars and compare it to your Vodka.  It’s not just the superior conductors and insulation that makes Vodka better! In the unlikely event that an unshielded cable does offer improved performance in your system, we could always re-terminate your cable without the drain wire attached."

 

I've compared BJC UTP and AQ Diamond, and the cost of the AQD alone should be enough to eliminate the so-called placebo effect.  In fact, I wanted to eliminate the AQD, but there's no denying the extra detail, clarity, presence, in fact a quality that made me sit up and smile in comparison.  I really don't have the money to spare, and wanted to put it towards something else, but I'll be keeping the AQD.

 

Music:

David Benoit - Freedom at Midnight, Kei's Song

Al Jarreau - My Favorite Things (w/ Kathleen Battle)

Thomas Gropper, Arcis-Vocalisten München, Barockorchester L'Arpa Festante  - Bach Kantata 182

Thierry Fischer, Mormon Tabernacle Choir, Utah Symphony  - Mahler 8

 

Equipment:

Server: Fanless Ubuntu file server, dual SSDs, bridged Ethernet w/JCAT Net card
Digital: dCS Vivaldi DAC 2.0, dCS NBR
Amps: D'Agostino M400
Speakers: Wilson Alexia 2
Cable: Shunyata Sigma
Power: Shunyata Denali 6000T, 2000T

[Darryl R]

On 8/20/2018 at 8:40 PM, plissken said:

 

I've a running offer of $5000 to anyones $1000 (loser also picks up travel expenses) that this can't be done when blinded. 

 

Part of the offer is I'll make a cable on the spot that tones out the same (shield etc) on the spot that is 3X longer than your AQ. 

 

I'll supply a server / client machine (with dual Intel GBE server NIC)running JRiver, and a managed layer 3 switch configured for dynamic LACP LAG. This will allow for me downing an interface or removing a network cable without interruption in playback. 

 

Two rounds of 10 possible, randomly chosen, swaps. You hit 16 for 20 and you are $5000 richer. 

 

Let me know your findings.  It appears I've been ruled out because mine was under $1K

 

You guys are fun, really.  And I truly appreciate all the participation in my thread.  I've nothing to prove, just merely posting my findings, and I wouldn't necessarily classify the difference as subtle.  Let me also reiterate that I wanted to put the money elsewhere, and I had the cable on contingency deal with a return authorization in my inbox* as I listened.  I did NOT want to hear a positive difference.

 

* no doubt some will say it was reverse psychology on the dealer's part .