SMPS and grounding

[Cornan]

39 minutes ago, BigGuy said:

IIRC, there was a much earlier post about the need to have the two ends of the shield connected to each other by an insulated wire otherwise the unconnected shield is just metallic sheathing.  Or does it serve a purpose even unconnected?

 

This would be the JSSG loop. My Ghent ET02 uses JSSG and the shield is not connected at either plug end, but have a drain wire connected to each end of the shield (loop). Ghent is using a Belden 1303E Cat6A CatSnake and Metz plugs. Sounds Great IMO!

[lmitche]

2 hours ago, BigGuy said:

IIRC, there was a much earlier post about the need to have the two ends of the shield connected to each other by an insulated wire otherwise the unconnected shield is just metallic sheathing.  Or does it serve a purpose even unconnected?

My post was meant to share my experience that the bjc 6a cable shields endpoints are not connected to the ethernet plugs.

 

I have no experience with insulated wire connecting shield endpoints. Likewise you will have to ask Belden about the advantages of the metal shield on their cables. I would be guessing.

[auricgoldfinger]

12 hours ago, R1200CL said:

If you buy the PoE version of that GS105, you don’t even need a PS ?

 

All problems solved ?

 

(no one has said the PoE is a no go YET)

 

And then a MicroRendu or UltraRendu driven by PoE......

 

Alex once said it will be fairly easy to make a 12 V LPS-1. Only reprogram the FPGA ?

 

Could we hope for a 12VDC version to all the people now buying 12 V switches ?

 

You could purchase two LPS-1's and hook their outputs up in series, with one set to 7V and the other to 5V to obtain 12V.

[thyname]

14 hours ago, thyname said:

A couple of (somewhat naive) questions:

 

1 - I know Jason’s ground plug and the SMPS need to be plugged in the same power strip, but can we have other (unrelated) devices plugged on the same power strip?

 

2 - Can we have other devices hooked up on the same Ethernet Switch when grounding the Switch? Or just the Streamer in question?

 

it is really great news that only the switch need to be grounded! Saves me from having my setup look like a high school science experiment if I had to ground all the various devices.

 

thanks!

 

Anyone? These should be very simple questions - more like a confirmation. Thanks

[auricgoldfinger]

1 minute ago, thyname said:

 

Anyone? These should be very simple questions - more like a confirmation. Thanks

 

2. You can have other devices on the same switch, but it is best to keep at least 1 empty port between cables.  John has explained why in his posts.

 

[charlesphoto]

4 minutes ago, auricgoldfinger said:

 

2. You can have other devices on the same switch, but it is best to keep at least 1 empty port between cables.  John has explained why in his posts.

 

 

I have not seen this explanation. Why is that? 

 

I would say that for what these switches cost (esp used) in relation to the rest of one’s system, just dedicate if possible one to the hifi only. I have a fairly full GS108 currently, but ordered a like new $10 FS105NA off eBay to isolate the streamer and server. Needed more room anyway. 

 

Personally, I’ve gone and grounded just about everything dc that even remotely comes into contact with the hifi and Ethernet and think it’s made a huge difference - transformative. No idea how much of it actually affects sound quality directly, but I am quite sensitive to EMF and can feel the overall level come down, esp in the TV/stereo corner, server closet, etc. I think even the Roku’s look and sound better. I could just be high too..... but at the cost I figured why not? 

[auricgoldfinger]

13 minutes ago, charlesphoto said:

 

I have not seen this explanation. Why is that? 

 

I would say that for what these switches cost (esp used) in relation to the rest of one’s system, just dedicate if possible one to the hifi only. I have a fairly full GS108 currently, but ordered a like new $10 FS105NA off eBay to isolate the streamer and server. Needed more room anyway. 

 

Personally, I’ve gone and grounded just about everything dc that even remotely comes into contact with the hifi and Ethernet and think it’s made a huge difference - transformative. No idea how much of it actually affects sound quality directly, but I am quite sensitive to EMF and can feel the overall level come down, esp in the TV/stereo corner, server closet, etc. I think even the Roku’s look and sound better. I could just be high too..... but at the cost I figured why not? 

 

I don't want to paraphrase what John has written on the subject.  You can search his posts for the most precise explanation.

[charlesphoto]

Ok. Not exactly sure what or where to search - this forum has became a bit dense to just put in switch and ports and find an easy search result.

[auricgoldfinger]

48 minutes ago, charlesphoto said:

Ok. Not exactly sure what or where to search - this forum has became a bit dense to just put in switch and ports and find an easy search result.

 

Go to his profile page and look at his posts.  You can also Google them.

[Cornan]

1 hour ago, charlesphoto said:

 

I have not seen this explanation. Why is that? 

 

I would say that for what these switches cost (esp used) in relation to the rest of one’s system, just dedicate if possible one to the hifi only. I have a fairly full GS108 currently, but ordered a like new $10 FS105NA off eBay to isolate the streamer and server. Needed more room anyway. 

 

Personally, I’ve gone and grounded just about everything dc that even remotely comes into contact with the hifi and Ethernet and think it’s made a huge difference - transformative. No idea how much of it actually affects sound quality directly, but I am quite sensitive to EMF and can feel the overall level come down, esp in the TV/stereo corner, server closet, etc. I think even the Roku’s look and sound better. I could just be high too..... but at the cost I figured why not? 

 

I think it is this one! ?

 

 

 

[thyname]

16 hours ago, thyname said:

A couple of (somewhat naive) questions:

 

1 - I know Jason’s ground plug and the SMPS need to be plugged in the same power strip, but can we have other (unrelated) devices plugged on the same power strip?

 

2 - Can we have other devices hooked up on the same Ethernet Switch when grounding the Switch? Or just the Streamer in question?

 

it is really great news that only the switch need to be grounded! Saves me from having my setup look like a high school science experiment if I had to ground all the various devices.

 

thanks!

 

We got the second question cleared up.

 

How about the first?

[Johnseye]

23 hours ago, JohnSwenson said:

This and every other article on Ethernet shielding is talking about the differential signal between the two wires in the pair. Leakage is common mode, it is the same on both wires (NOT differential) thus the twistedness does not matter. Because it is common mode noise the twisted pair just looks like a weirdly shaped single conductor and makes a nice antenna.

 

I do NOT recommend shielded Ethernet in most cases, leakage will go through the shield, bypassing all things I have written about blocking it, none of that works if you have connected shields.

 

That is why I recommend using UTP and putting one of the grounded named swithces some distance away from the audio system, there will be nothing on the cable to radiate.

 

John S.

 

19 hours ago, rickca said:

Is BJC Cat 6A OK to use?  It's supposed to have a floating shield.

 

19 hours ago, lmitche said:

I have lots of belden based bjc cat 6a cables and having re-terminated several, know that the cable is shielded but floating on both ends.

 

The internal structure of this cable is really something. I have no idea how they can cheaply manufacture something with this complexity.

 

It sounds like cat 6a is ok to use, and may even be better because of the shielding as long as the shield is floating.  Is this accurate?

[Cornan]

3 minutes ago, thyname said:

 

We got the second question cleared up.

 

How about the first?

 

I can only tell my own experiances where grounding the DC- output of a psu powering ISO Regen and DAC to the same grounding point as DC- output of psus powering network devices is a bad idea SQ wise.

[lmitche]

25 minutes ago, Johnseye said:

 

 

 

It sounds like cat 6a is ok to use, and may even be better because of the shielding as long as the shield is floating.  Is this accurate?

Oh boy, I guess we are having reading comprehension issues today, LOL!

[Superdad]

9 hours ago, kboung said:

Regarding combination of iso-regen powered by LPS-1

 

(1) For "tick/dropout" issue with iso-regen, it was recommended to ground downstream of iso-regen

(2) For high impedance leakage with LPS-1, it was recommended to ground Meanwell output negative

 

In this case, both groundings required or (1) will actually cover for (2)?

 

Maybe Alex or John can clarify. Thanks.

 

Hi Kboung:

 

If one is using an UltraCap LPS-1 to power the ISO REGEN, then no, grounding [the zero-volt "neg./grd"] of an SMPS that is "energizing"/charging the LPS-1 is NOT the same thing as grounding the downstream side of the ISO REGEN (the DAC's USB input).

 

This is because the LPS-1 is an isolated/"floated" PS (notwithstanding the newly discovered high impedance common-mode leakage which can creep across the unit's 100pF of capacitance between power domains), and its input and output "grounds" are not common to each other.

By the way, most people do not end up needing to ground the output side of their ISO REGEN.

 

Hope the above clears things up for you.

 

--Alex C.

[Special Snowflake]

Alex when are you going to release a DAC? I’m in the market, but don’t want to purchase anything until I know if you’re building one or not. 

[Johnseye]

1 hour ago, lmitche said:

Oh boy, I guess we are having reading comprehension issues today, LOL!

 

Why wouldn't you answer the question instead of responding like that?

[Superdad]

1 hour ago, lmitche said:

Oh boy, I guess we are having reading comprehension issues today, LOL!

 

21 minutes ago, Johnseye said:

 

Why wouldn't you answer the question instead of responding like that?

 

Chill guys.  I know it is confusing.  On my call with John last night I brought this up because it seemed at first glance that he was contradicting himself.

First off:

His comment about unshielded CAT cable radiating common-mode leakage was based on actual experience on his test bench where his specialized leakage measurement set up was picking up a large amount of stuff that he could see on his scope as he moved the UTP around.  

Yet of course a normal shielded CAT cable (6A) that has the shield tied at both ends (metal shel around the RJ45) is undesirable for our purposes because it reduces isolation by joining grounds between boxes and giving a path for both other leakage--and potentially noise.

 

The BlueJeans/Belden CAT6A does not tie its shields at all, but that shield may not be doing much for us.  It would be very effective if John's external shield wire loop trick was applied to that (external wire running between the shield ends).

 

But ALL the above is a moot point if one is using an Ethernet switch (such as the Netgear FS/GS units) that have been confirmed to shunt high-impedance leakage (from both an SMPS powering it and from the gear/cables feeding it).  

And that is where John's recommendation to put the Netgear switch at the end with your computers/router/etc.--and just run a single long cable to your hi-fi renderer.  Since the leakage will then not be on the cable (due to blocking by the Netgear), it then does not matter if the CAT cable is UTP or STP!

 

Hope that clears this up.  

[Johnseye]

Thanks for the intelligent response.

[Special Snowflake]

6 minutes ago, Superdad said:

 

 

Chill guys.  I know it is confusing.  On my call with John last night I brought this up because it seemed at first glance that he was contradicting himself.

First off:

His comment about unshielded CAT cable radiating common-mode leakage was based on actual experience on his test bench where his specialized leakage measurement set up was picking up a large amount of stuff that he could see on his scope as he moved the UTP around.  

Yet of course a normal shielded CAT cable (6A) that has the shield tied at both ends (metal shel around the RJ45) is undesirable for our purposes because it reduces isolation by joining grounds between boxes and giving a path for both other leakage--and potentially noise.

 

The BlueJeans/Belden CAT6A does not tie its shields at all, but that shield may not be doing much for us.  It would be very effective if John's external shield wire loop trick was applied to that (external wire running between the shield ends).

 

But ALL the above is a moot point if one is using an Ethernet switch (such as the Netgear FS/GS units) that have been confirmed to shunt high-impedance leakage (from both an SMPS powering it and from the gear/cables feeding it).  

And that is where John's recommendation to put the Netgear switch at the end with your computers/router/etc.--and just run a single long cable to your hi-fi renderer.  Since the leakage will then not be on the cable (due to blocking by the Netgear), it then does not matter if the CAT cable is UTP or STP!

 

Hope that clears this up.  

Haven’t audio gear manufacturers figured out how to make wifi sound good yet? How could leakage currents from the router make it into the gear through the airwaves? 

[thyname]

2 minutes ago, Special Snowflake said:

Haven’t audio gear manufacturers figured out how to make wifi sound good yet? How could leakage currents from the router make it into the gear through the airwaves? 

 

Oh no!!!! Then we would be buying audiophile air....

[Special Snowflake]

Just now, thyname said:

 

Oh no!!!! Then we would be buying audiophile air....

Yeah I suppose if we remove the cable from the equation, we would miss out on many problems to solve. 

[Superdad]

1 minute ago, thyname said:

Oh no!!!! Then we would be buying audiophile air....

 

Well I eat audio-nuts for breakfast so I pass audiophile gas.  It's not wifi, but I guess it is an ether-or situation...

[thyname]

1 minute ago, Special Snowflake said:

Yeah I suppose if we remove the cable from the equation, we would miss out on many problems to solve. 

 

Joking aside, there are many people that already think that wifi is best for streaming, including @plissken

[thyname]

Just now, Superdad said:

 

.... it is an ether-or situation...

 

LOL! Good one!