Shielded vs. unshielded Ethernet and Grounding

[mansr]

32 minutes ago, Em2016 said:

While I'm with the unshielded ethernet group, I was looking through an Icron user manual and noticed this:

 

 

http://www.icron.com/pdf/el5363-hdmi-usb-2-0-manual.pdf

 

They have quite a bit of experience in both networked audio AND video, so there must be something to their recommendation, especially their notes on interference?

 

They're obviously not fans/believers of the balanced and isolated nature of unshielded ethernet.

 

It doesn't change the fact that shielding may open the door to a ground / leakage loop but they must have seen/measured this interference they mention.

 

I'll tag the respected experts @JohnSwenson @Miska @mansr @jabbr

I don't think that device uses Ethernet signalling, so there's that. Regardless, even balanced twisted pair can suffer under extreme interference. That's why shielded Ethernet cables exist. The usual advice for audio purposes is to use unshielded cabling if conditions permit since an unnecessary shield won't improve anything and may cause other problems. If outside interference makes communication unreliable over unshielded cables, there is obviously no other choice than to use shielded.

[asdf1000]

51 minutes ago, mansr said:

I don't think that device uses Ethernet signalling, so there's that.

 

But it's HDMI video and USB 2.0 audio, over ethernet? A LEX and a REX unit.

 

http://www.icron.com/products/icron-brand/kvm-extenders/cat5/el5363-hdmi-usb-2-0/

 

 

[mansr]

37 minutes ago, Em2016 said:

But it's HDMI video and USB 2.0 audio, over ethernet? A LEX and a REX unit.

 

http://www.icron.com/products/icron-brand/kvm-extenders/cat5/el5363-hdmi-usb-2-0/

It uses Ethernet cables, but (probably) not Ethernet signalling. 1080p60 video requires about 3 Gbps, so the demands of this device are higher than those of regular GbE.

[Ralf11]

curious about the forthcoming etherREGEN...

 

is it intended as a high priced ($3,000 level) sort of item?  or much lower?

 

is it going to be specialized for ethernet only?

[mansr]

15 minutes ago, Ralf11 said:

curious about the forthcoming etherREGEN...

 

is it intended as a high priced ($3,000 level) sort of item?  or much lower?

 

is it going to be specialized for ethernet only?

My understanding is that it's simply an Ethernet switch, just as the regular Regen is a USB hub. The recipe looks the same. Take a regular switch/hub, remove most of the ports, install some over-specced clocks, and watch the money roll in.

[Miska]

I can measure effect of ground currents through shields, but not interference that doesn't cause packet loss or any other directly related effects.

 

So far, since last reboot, my network interface has transferred 4 terabytes of data without errors, over CAT6 UTP.

 

What you are referring to doesn't seem to have anything to do with Ethernet, it only uses same cabling and connectors for completely different signaling. A bit like I2S over HDMI cables/connectors.

 

If you need to put stereo DSD512 over gigabit ethernet, you need to do 50 Mbps over 1 Gbps link, so you can do shitload of retransmissions due errors (because of interference or whatever) and still meet the needed bandwidth. But if you have ground current through the shield, it doesn't matter at all if the transmission is perfect as it can be, because things are completely ruined outside of the data transmission.

 

[Kal Rubinson]

50 minutes ago, Miska said:

If you need to put stereo DSD512 over gigabit ethernet, you need to do 50 Mbps over 1 Gbps link, so you can do shitload of retransmissions due errors (because of interference or whatever) and still meet the needed bandwidth.

Running 6 channel DSD256 smoothly over CAT6 UTP.

[jabbr]

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?

[Superdad]

8 hours ago, Ralf11 said:

curious about the forthcoming etherREGEN...

 

is it intended as a high priced ($3,000 level) sort of item?  or much lower?

 

is it going to be specialized for ethernet only?

 

4 Gigabit copper Ethernet ports, 1 Gigabit SFP cage, 1 10/100Mbps ultra-clean and isolated port (expensive GMR isolators), low-phase-noise master clock driving clock synthesizer for various clocks, LT3042/45 LDO regs, specially chosen magnetics for best leakage isolation, and a few other details.  

Price to be much lower than competitive units that are simply modified off-the-shelf switches—versus our from-the-ground-up approach.  Targeting $500 but it depends upon final BoM cost.

https://www.computeraudiophile.com/forums/topic/38968-etherregen-early-general-details-please-dont-ask-too-many-questions-yet/

 

 

8 hours ago, mansr said:

My understanding is that it's simply an Ethernet switch, just as the regular Regen is a USB hub. The recipe looks the same. Take a regular switch/hub, remove most of the ports, install some over-specced clocks, and watch the money roll in.

 

Your understanding is wrong.  Except for the very last part, where the money rolls in—due to happy customers enjoying audible benefits and a solid value. Same as with our other products—all sold with a 30-day, money-back guarantee. 

[Ralf11]

Thx - those are the NVE Spintronics devices?

[Superdad]

22 minutes ago, Ralf11 said:

Thx - those are the NVE Spintronics devices?

 

Yes.  John has been using them for years.  They are far better than any other digital isolator.  Among their many positive attributes is that they introduce less jitter than RF, optical, or capacitive isolators.

[plissken]

10 hours ago, Superdad said:

 

4 Gigabit copper Ethernet ports, 1 Gigabit SFP cage, 1 10/100Mbps ultra-clean and isolated port (expensive GMR isolators), low-phase-noise master clock driving clock synthesizer for various clocks, LT3042/45 LDO regs, specially chosen magnetics for best leakage isolation, and a few other details.  

Price to be much lower than competitive units that are simply modified off-the-shelf switches—versus our from-the-ground-up approach.  Targeting $500 but it depends upon final BoM cost.

https://www.computeraudiophile.com/forums/topic/38968-etherregen-early-general-details-please-dont-ask-too-many-questions-yet/

cts—all sold with a 30-day, money-back guarantee. 

 

Looking forward to empirical data.

[adamdea]

1 hour ago, plissken said:

 

Looking forward to empirical data.

you mean sales figures?

[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

[Ralf11]

Air Defense for Everybody!

[jabbr]

17 hours ago, Superdad said:

 

4 Gigabit copper Ethernet ports, 1 Gigabit SFP cage, 1 10/100Mbps ultra-clean and isolated port (expensive GMR isolators), low-phase-noise master clock driving clock synthesizer for various clocks, LT3042/45 LDO regs, specially chosen magnetics for best leakage isolation, and a few other details.  

Price to be much lower than competitive units that are simply modified off-the-shelf switches—versus our from-the-ground-up approach.  Targeting $500 but it depends upon final BoM cost.

https://www.computeraudiophile.com/forums/topic/38968-etherregen-early-general-details-please-dont-ask-too-many-questions-yet/

 

 

Not bad!

 

There is a market for a consumer audiophile type switch. Hopefully one that can meet professional switch specs.

 

17 hours ago, Superdad said:

 

Your understanding is wrong.  Except for the very last part, where the money rolls in—due to happy customers enjoying audible benefits and a solid value. Same as with our other products—all sold with a 30-day, money-back guarantee. 

 

Your, the UpTone, products are very reasonably priced, particularly given the small audiophile market. 

 

I would like to see to see an end-to-end jitter/phase noise measurement the same as which is specified for the 10GBase-X Ethernet spec (2002) ie <5.5 picosec end to end jitter. Not required for 10/100 Mb Ethernet but give me a reason not to use a 10G switch at 1G, for example.

[Fitzcaraldo215]

27 minutes ago, jabbr said:

 

Not bad!

 

There is a market for a consumer audiophile type switch. Hopefully one that can meet professional switch specs.

 

 

Your, the UpTone, products are very reasonably priced, particularly given the small audiophile market. 

 

I would like to see to see an end-to-end jitter/phase noise measurement the same as which is specified for the 10GBase-X Ethernet spec (2002) ie <5.5 picosec end to end jitter. Not required for 10/100 Mb Ethernet but give me a reason not to use a 10G switch at 1G, for example.

When you say "end to end" that must necessarily include the DAC, unless you think that is of no importance in our setups.  

 

Of of course it is.  In fact everything upstream really doesn't matter unless the analog output from the DAC is measurably affected.  So, why not just measure a range of DACs for  traditional audio frequency, noise, jitter, etc. with these various network transmission "improvements"?

 

Count me skeptical, but I have a hunch the results will not be dramatic, especially with certain DACS, and that much of these heroic efforts to improve the input to the DAC will not result in commensurate improvements at the output.

[jabbr]

17 minutes ago, Fitzcaraldo215 said:

When you say "end to end" that must necessarily include the DAC, unless you think that is of no importance in our setups.  

 

The good thing about IEEE specs is that the measurement details are specified. The standard measurement is what I’d like to see at a minimum for an Ethernet switch that claims to have improved functionality over consumer off the shelf $15 units. IEEE 2002 made a conscious decision not to specify the specs on individual components such as clocks, psus etc, rather looking at end-to-end specifications. That was >15 years ago.

[plissken]

14 hours ago, jabbr said:

I would like to see to see an end-to-end jitter/phase noise measurement the same as which is specified for the 10GBase-X Ethernet spec (2002) ie <5.5 picosec end to end jitter. Not required for 10/100 Mb Ethernet but give me a reason not to use a 10G switch at 1G, for example.

 

I would like to see bias controlled testing where we take JRiver with a large pre-buffer, or Tidal, play a track and disconnect the Ethernet cable and see if ears can track it (they wouldn't know if the cable is in or out). 

 

I wonder what the jitter on that would be in seconds. 

[Emcee]

What about something like BJC Cat 6a which have a ''floating'' shield (unattached at each end)?

 

I also have the Supra Cat 8 STP which introduced a nasty buzz in my system until I removed the copper jacket on one connector.

 

Is either of these theoretically better/worse than basic unshielded Monoprice Cat 6?

[jabbr]

7 minutes ago, Emcee said:

What about something like BJC Cat 6a which have a ''floating'' shield (unattached at each end)?

 

I also have the Supra Cat 8 STP which introduced a nasty buzz in my system until I removed the copper jacket on one connector.

 

Is either of these theoretically better/worse than basic unshielded Monoprice Cat 6?

?

[plissken]

3 minutes ago, Emcee said:

What about something like BJC Cat 6a which have a ''floating'' shield (unattached at each end)?

 

I also have the Supra Cat 8 STP which introduced a nasty buzz in my system until I removed the copper jacket on one connector.

 

Is either of these theoretically better/worse than basic unshielded Monoprice Cat 6?

 

Shield normally presents a problem when it's connected to chassis. When I see a boutique cable company make Ethernet cabling with shield tied chassis then I know they are clueless and did zero homework. 

 

Bottom line is that for audio applications in the home UTP is superior to STP. 

 

Enhanced CAT6 has foil around the individual pairs to prevent interpair cross talk. This is called foil twisted pair (FTP). 

 

With a shield that is fully floated around all the pairs then it's to prevent intercable cross talk. This is how BJC does it and it won't allow for a ground loop. 

 

For a fact CAT5E is orders of magnitude capable of exceeding data rates that audio requires. I don't know of a modern audio only standard that would make properly implemented 5E even break a sweat.  

[mansr]

20 hours ago, jabbr said:

I would like to see to see an end-to-end jitter/phase noise measurement the same as which is specified for the 10GBase-X Ethernet spec (2002) ie <5.5 picosec end to end jitter.

How is that relevant for audio? The DAC isn't running off the link clock.

[jabbr]

1 hour ago, mansr said:

How is that relevant for audio? The DAC isn't running off the link clock.

It’s not relevant for you nor intended to be, however for people for whom upgrading Ethernet switch clocks or for whom cable shields, avoiding leakage currents is important, of for anyone interested in Ethernet signal integrity, I am pointing out that IEEE standards for 10Gbe fiber already have very stringent requirements and people should get some comfort in using equipment which meets such standards.

[Fitzcaraldo215]

1 hour ago, jabbr said:

It’s not relevant for you nor intended to be, however for people for whom upgrading Ethernet switch clocks or for whom cable shields, avoiding leakage currents is important, of for anyone interested in Ethernet signal integrity, I am pointing out that IEEE standards for 10Gbe fiber already have very stringent requirements and people should get some comfort in using equipment which meets such standards.

Ok, but if those efforts have no provable effect on the output from the DAC, other than giving people "comfort", of what relevance are they to our listening?