The EtherREGEN thread for various network, cable, power experiences and experiments

[JohnSwenson]

2 hours ago, HumanMedia said:

My system is wireless endpoint to ER, to UltraRendu, to DAC.

 

The UltraRendu is on its own JS-2. I know if I put the ER on the other output of the JS-2, it is not recommended, shared 0v etc. But what if the other JS-2 output was charging an LPS 1.2? And the LPS 1.2 powered the ER? Would this break the shared 0v and be OK?

Yes, the LPS-1.2 breaks the connection.

 

Try swapping what you power by the LPS-1.2, you may find you like one way batter than the other.

 

John S.

[JohnSwenson]

4 hours ago, stevebythebay said:

John:

 

I’ll be installing a JS-2 to support both the EtherREGEN and a Roon Nucleus soon. The “A” side of the EtherREGEN has both of these wired in along with a WiFi router (Eero mesh).  

 

As I understand it, I should connect the ground on the EtherREGEN.  I’ve ordered up a Desco banana jack ground plug adapter and associated cable To plug into an available wall socket. I’m assuming it shouldn’t matter what circuit receptacle I plug this into.
 

Just checking for any other recommendations on noise mitigation or placement for the EtherREGEN. 

Unfortunately the exact "ground" to use for "BEST" results is not necessarily easy to figure out. The simple answer is any socket connected to safety ground. There MAY be very subtle differences with connecting to grounds from different circuits.   You can certainly try different sockets if you have different circuits near the ER. The best is usually the closest to the ER so you use the shortest ground wire.

 

John S.

[JohnSwenson]

The voltage range is from 7 to 12V. It generates the same amount of heat no matter what the voltage is.

 

There may be some people that hear a slight sound difference with different voltages, but there is no specific engineering reason for choosing one voltage over another.

 

John S.

[JohnSwenson]

1 hour ago, Jud said:

After having read the user manual a bit, I have a question: Let's assume (though I haven't yet got the cables and tested with a multimeter) the Cable Matters Cat 8 patch cable metal connectors are shield-tied at both ends.

 

My system is as follows: Modem to router to ER to microRendu to IsoREGEN to DAC. In each case there is only one Ethernet or (to the IsoREGEN and DAC) USB connection. ER, microRendu, and IsoREGEN are powered by UpTone ground shunted SMPSs. The DAC is powered by an LPS-1 energized by another UpTone ground shunted SMPS. Modem and router are powered by their own SMPSs.

 

I understand the "B" side Ethernet connection from the EtherREGEN to the microRendu is not a concern regarding leakage loops. What I wondered was whether using cables with continuity through the shields for the single "A" side connection between the router and the EtherRegen, and/or the connection between modem and router, would pose a concern regarding leakage loops in this configuration.

Very good question.

All Ethernet devices have transformers on the signal lines which are supposed to prevent traditional ground loops, low frequency leakage and other electrical "muck" from winding up on the data lines. When you use end to end tied cable you you MAY be directly connecting the ground planes of devices together. Some devices have the shield of the jack connected through a cap to the ground plane of the device, some do not. If the cap is there you do not get a full galvanic connection but many types of signals will go right through the cap.

 

So in essence you are bypassing a lot of the isolation that is designed into the system. Whether this is going to cause a problem again depends on your setup. Do you have something connected to the A side that is important (maybe a TV or receiver etc), then using  end to end tied cables for connections to the A side devices may yield compromised performance. If all you have on the A side are things such as a router and a NAS, it may not matter.

 

Unfortunately there is no hard and fast rule here, you may find that the "better" cables attributes are mitigated by the shield tied configuration in some configurations. The only way to find that out is to try.

 

John S.

[JohnSwenson]

12 hours ago, Jud said:

 

Two follow-up questions:

 

- Will the UpTone ground shunted SMPS power a device using a 12V 2.5A power supply, and what about a 12V 1.5A device?

 

- Would powering my modem and router with the UpTone SMPSs possibly help at all in my configuration (it would mean all Ethernet-connected devices would be using the ground-shunted power supplies)? Or still the same answer, try and see if it helps?

The uptone supply is 7.7V at 4.8A. Whether this can power a device that is rated at 12V very much depends on the device itself. Just as the ER will work fine 7-12V some other devices may also, just pulling more current at the lower voltage. BUT they may not work at when fed by 7.5V. There is no way I can tell you whether that is true for any other device unless the documentation specifically specifies an input voltage range that includes 7.5v.

 

The questions about things like grounding and cables etc, are difficult questions, it depends very much on exactly what you have, and how it is connected, both audio system cables and power connection and exactly how all the power supplies in all your equipment behaves, there is just no easy way to answer these questions without hours worth of work on my part and I simply don't have the time to do that. So I'm going to have to say that I'm not going to put any effort into trying to answer such questions from now on, I simply don't have the time or brain power left to try and analyze these questions. You won't actually physically damage anything if you manage to hook things up in a sub-optimal way, so just try. If someone wants me to tell them whether they should spend $1000 on a specific cable I simply cannot do that.

 

John S.

 

 

[JohnSwenson]

10 hours ago, Meridimac said:

Season's Greetings!  I expect ER in January to replace a Cisco 2960 in my main setup. My question is about the best way to serve a second, remote system connected by in-wall Cat5e (which can travel through a gigabit Catalyst switch, or not) to a ground-shunted Netgear GS-108 located 125 feet away.

 

Summary of Qobuz/Tidal/Roon current streaming situation:

 

Fiber internet provider (Zhone modem) serves Ubiquiti EdgeRouter X SFP (router) wired Cat6 to Intel 7i7BNH NUC running ROCK plus SFP optical fiber to Cisco Catalyst 2960 switch connected by Shunyata Venom ethernet cable to ALLO DigiOne Signature transport which outputs S/PDIF via Blue Jeans cable and SpeakerLink to Meridian DSP5200SE active speakers.

 

Along with other source electronics, ER will be plugged into a Shunyata power strip with Defender AC filter and Alpha NR 20A mains cable on a dedicated circuit. Roon core NUC and a Meridian 218 endpoint will be on A side (with SFP optical) while ALLO endpoint is on B.

 

Questions: Include ethernet to remote system on A side, or run from router? Pass through Cisco gigabit switch or use couplers direct to Netgear? Re-purpose 10/100 Cisco 2960 for remote (also ALLO) endpoint after Netgear, which serves TV, Apple TV, DirecTV?

 

TIA for any suggestions.

 

You want to keep the ER near the ALLO without any boxes in between. I would probably run the existing optical connection from the Ubiquity router to the optical SFP on the ER. This sounds like it is just swapping the 10/100 2960 for the ER, correct? Is the router near the ER? Is the 125ft cable near the ER?

 

If the router, ER and 125ft cable all near each other it seems you have several ways to hook this up:

 

1) ER optical from router, 125 cable from router, gigbit 2960 or Netgear at other end

2) gigabit 2960 from router, 125ft cable from gig 2960, Netgear or 10/100 2960 at other end

3) gigabit 2960 from router, 125ft cable AND optical to ER from gig 2960, Netgear or 10/100 2960 at other end

4) 10/100 2960 from router, ER from 10/100 2960 optical,  125ft cable from router, gig 2960 on other end.

 

The 10/100 2960 has one gig port and the rest 10/100 so whether you can use it at the end of the 125ft cable depends on if the TV etc can run at 100 or if the NEED gigbit.

 

Several people have stated that the ER driven by a 2960 sounds better than the ER directly into a router. The SFP port on the 10/100 2960 IS gigabit, so it can talk to the SFP on the ER.

 

I'm getting a feeling that #4 probably gives you the best over all optimization.

 

John S.

 

 

[JohnSwenson]

3 hours ago, Meridimac said:

Hi John. Thanks for the quick reply.

 

The ER will be close to the Ubiquity router which has one SFP optical for connection to the ER optical. So, yes, I will just swap your switch to replace my existing Cisco model WS-C2960-8TC-L. Because it has 10/100 out, it can't then replace the remote gigabit Netgear serving the AV pieces 125 feet away, but could sit between the Netgear and distant Roon endpoint if you think there would be a benefit. Every item mentioned can connect to ER or the router.

 

The other Cisco switch Catalyst WS-C2960G-24TC-L serves everything in the house from the router EXCEPT the main audio system which is isolated by the optical connection. This gigabit switch can be bypassed, using couplers, should I want to have the remote audio system directly connected to the A side like I plan for the Roon core NUC and a Meridian 218 endpoint (which is waiting for that company to finally, someday update the firmware).

 

Do I bypass the Cisco that feeds all kinds of other stuff to keep everything audio on the ER?

 

BTW, in theory, I could also bypass the Netgear from ER side A using an optical converter directly to the SFP cage in the potentially remote 10/100 Cisco because I bundled fiber in with cat5e everywhere when I built the house, but have never pulled it out from behind the wall plates or spliced it.

 

 

Since you are running optical into the ER, it is probably better to just have that connection into the ER and hook other stuff up to the 2960, although if they are near each other you could try it both ways and see what sounds best.

 

There is no obvious "this will definitely be the best", so it looks like if you really are interested in optimizing the system you are going to have to try some things out and see what sounds best.

 

John S.

[JohnSwenson]

There has been some discussions about thermal issue with the ER and I'd like to go into a little detail about how this all works. There is a lot of partial understanding of this that can cause people to make bad decisions. (BTW this is generic, ALL electronics follows this).

 

To see how the system works thermally start at the outside of the case, its thermal properties are by far the biggest factor, the internal details have very little to do with it. (I know that sounds bizarre , but it's true).  What matters for a case like the ER which is a closed case made out of aluminum, which reaches an equilibrium where the entire case is all at almost the same temperature, is how how well the case gets rid of the heat AND the total power being generated inside the case.

 

This type of case has two primary means of getting rid of heat: IR radiation and air movement in contact with the surface. Without a fan blowing air across the surface both of these are heavily determined by the temperature of the case. As the temperature goes up more heat goes out through IR, and more air convection happens. BTW in this particular case, the IR is the biggest contributor to getting the heat out, not air. So what happens is the case reaches a temperature that produce IR and convection power that equals the total amount of power generated by the circuit. That's it. The temperature of the case has nothing to do with the internal structure, whether things are connected by metal to the case or just air etc. NONE of that matters for case temperature. It is entirely the equilibrium temperature where internal heat flow matches external heat flow.

 

The structure INSIDE does matter for the temperature of the board though. The temperature of the board is again an equilibrium of the heat coming from the board and how efficient the board can get heat to the case. We know from thermodynamics that the board HAS to be hotter than the inside of the case, how much hotter depends on the hat transfer efficiency of the board. It turns out that the common PC board is actually pretty good at doing this, and most of it is IR radiation not air. It turns out that for a system like the ER the board temperature is only a degree or so hotter than the case! Even when there is just air between them! There is no need for direct metal to case connections, it would only drop the board temperature by a fraction of a degree.

 

This only works when most of the heat being generated by the devices on the board gets coupled well to the board and the internal power and ground planes do a good job of spreading the heat around throughout the board. in the ER case it is a six layer board with a LOT of P/G planes that do a VERY good job of this.

 

The only issue is that some of the small devices do not couple well into the board, their size is so small they just can't transfer their heat dissipation well into the board. Most of the devices on the board DO couple well and the device temperatures are only a few degrees hotter than the board. BUT a few of them don't couple well and they are much hotter than the board. These are the ones that have the heatsinks, this adds another path to get the heat from the device to the case (again IR and convection) The result is these devices are quite a bit cooler then they would be without the heatsink. (they still are hotter than the board, but not by much) Note these internal heatsinks do not change the case temperature one bit, the total heat stays the same, they just lower the temperature of certain devices that have a hard time getting their heat into the board.

 

We spent a lot of work on this, analyzing, measuring, trying different things etc. The result is a well integrated thermal system where every device runs at well below its thermal rating. Nothing you could do on the inside will make the parts run any cooler. The only thing that really matters is getting the case itself cooler, external heat sinks, external air flow etc. But you have to do a LOT of this to make a big difference since a large percentage of the total case heat flow comes from IR, air flow changes only make a fairly small change in the total.

 

One very important thing to understand is that the IR emission from a black surface is vastly greater than from a bare metal surface, so putting a bare metal heatsink on top of an ER will actually increase the  temperature of the case because you are almost stopping the IR emission. If you DO use a heatsink make sure it is black!

 

This brings up another interesting way to cool the thing, put a black thick aluminum plate under the ER, the bottom will transfer a lot of heat to the plate through IR, which then spreads out through the plate into the environment. You could also make that into a nice anti vibration platform.

 

The temperature inside the case does not inherently matter to the oscillator, but it DOES affect the thermal sensitivity. All crystal oscillators have a sensitivity to temperature change, but it is not constant. At a certain temperature the temperature coefficient is zero. Far away from that temperature small changes in temperature make a fairly big change in frequency. The zero point for the oscillators we use are a little above common room temperature, so at the temperature they are at inside the case they are definitely above the zero point so they become somewhat sensitive to temperature changes. This is why reaching thermal equilibrium is quite important. You want to keep the temperature stable because the oscillator is sensitive to temperature change. The cooler the case is the less this sensitivity is.

 

There you go, far more than you ever wanted to know about thermal flow and electronics.

 

John S.

[JohnSwenson]

1 hour ago, kennyb123 said:

 

I'm thinking it's likely that the choice of SFP will dictate how likely attenuators might be needed.  If there haven't been reports of a hot treble from the guys playing with the opticalRendu, it could very well be that the SFP that Sonore recommended doesn't need to be used with attenuators.  I selected Startech SFPs based on the endorsement of Emile from Taiko Audio.  I have no idea if these would be any better than what Sonore recommends.  You could maybe start there though as those SFPs are very reasonably priced - Sonore sells them for $20 each.  

Just look at the rated distance compared to what you will be using. The ones you are using are rated at 40KM, the SX ones are rated at 500M. Those 40KM ones need a very powerful laser to reach that distance, with a short cable (like what you would have in a house) it is severe overkill and can fry the receiver. The 500M ones have a much lower power laser which works fine with the short cables we use for audio.

 

There MAY be things that make the 40KM ones better (maybe better receivers etc, I have no clue what is inside) that might make it worth it, but I would start with the SX ones get familiar with them and then later try playing with the ones that seem a little out there for this purpose.

 

John S.

[JohnSwenson]

As far as I can tell these "grounding" boxes are really noise injectors, BUT with phase adjusted so it tends to cancel out noise already in the system. The box is an antenna which picks up the AC line frequency already in pretty much all environments and injects it into the "ground" of your system. If this is done properly it CAN cancel out some of the existing ground noise, but it can also increase it if things are not right.

 

The upshot is that if you have setup these boxes and tuned things right and them you use something to decrease the ground noise (such as an EtherREGEN) you may find that things sound worse, because now the injected noise from the ground box doesn't have anything to cancel out. So I would recommend trying the EtherREGEN both with and without the ground boxes and see what you prefer.

 

John S.

[JohnSwenson]

20 hours ago, nkbg said:

 

I am using a 7V Farad on the ER.

 

I made a cable using V-Quad Cu21 wire from VH Audio (https://www.vhaudio.com/v-quad.html), Oyaide connector, WBT solder. It did improve everything by a notch - quieter and calmer. Chris at VH is great to deal with as well.

 

This is really good cable, it should make a superb DC cable.

 

John S.

[JohnSwenson]

4 hours ago, TwinPeak said:

I finally managed to connect my Ubiquiti X-SFP router to the audio network and EtherREGEN's SFP-port - by single-mode SFP's and a single-mode optical cable. Coached and instructed by user octaviars until everything was up and running. The trick was configuring the Ubiquiti's SFP-port setup (on browser)  - and swapping ends of the single-mode optical cable so that EtherREGEN's SFP was using Blue cable end (UPC) and Ubiquiti the Green (APC). Bingo!

 

So how does it sound? Well, in my system the internet connection via EtherREGEN is actually only for being able to manage my Mac Mini and EtherREGEN's attached devices (NAS, UltraRendu etc). But it did have an impact on sound quality: Blacker background, better female voices, more dynamics, especially in low frequencies and improved overall clarity - it sounds more like "analog".

 

The question is if the improvements I hear is caused by the absence of a "dirty" regular internet connection to EtherREGEN and A-side connected devices - or is it the galvanic isolated single-mode fibre connection? I listened for eventual "trade-offs" or something missing, but couldn't find anything. I will call it a great improvement.

PS! I have ordered a set of regular duplex SFP's and optical cable - just to be on the safe side...

There seems to be a bit of a misconception here, that the EtherREGEN is getting rid of noise coming in over the internet, this is not true, it is getting rid of noise coming from the networking equipment in your home: modem, router, switch, other devices connected to the network. This noise can exist even if you don't have any form of internet connection. The noise is a combination of leakage current from the SMPS powering the network equipment and phase noise coming from the cheap oscillators inside said equipment.

 

John S.

[JohnSwenson]

2 hours ago, OldBigEars said:

 

Doesn't that make the ER run even hotter than the standard 7v PS?  It already gets quite hot....

No it doesn't, the amount of power the devices uses is independent of the supply voltage (within the specified range of 7-12V).

 

John S.

[JohnSwenson]

1 hour ago, chungjh said:

Is anyone using vibration isolators for ER? Any difference?

I have mine on a 1/2" thick aluminum slab which sits on roller bearings from Ingress Engineering.  Over the last 5 years or so I have done a lot of experimenting and listening and this configuration gives the best results, particularly for digital devices.

 

The roller bearing are single base types, the machined aluminum base sits on the shelf with a ball bearing sitting on the base. The aluminum slab has polished stainless steel sheets (outdoor pocket "shaving mirrors" ) glued to the bottom (I use rubber cement) where i want the slab to sit on top of the balls.

 

This combination does a very effective job of blocking seismic waves from reaching the crystals in the oscillators. As far as I have been able to tell seismic waves (very low frequency waves in the ground, caused by ground heating and cooling and nearby trucks or trains) are one of the biggest contributors towards oscillator output contamination. These temperature change induced seismic waves are one of the reasons a lot of people like listening in the middle of the night, the ground temperature has stabilized thus produces much less intense seismic waves.

 

Unfortunately there is a correlation that the oscillators with the lowest phase noise also have the highest sensitivity to seismic waves, so measures like these can become quite important for very high quality digital systems.

 

A few words on the aluminum slab. The 1/2" thick aluminum plate has several very good properties one one bad property.

 

The good:

thick aluminum is a good absorber of higher frequency vibrations. It is good shielding both for electrical waves AND magnetic waves (thin aluminum sheets do not shield well from magnetic fields, but thick ones do). At 1/2" it is very rigid so provides a good base for dealing with the low frequency seismic waves. Sheet metal (particularly the case of most electronics) bends at these low frequencies significantly decreasing the effectiveness of the roller bearing

 

The bad:

thick aluminum "rings" like crazy. This after all is how wind chimes work. It turns out the ringing is caused by surface acoustic waves forming standing waves on the surface of the aluminum. Fortunately this can be damped out by things touching the surface, thus scattering the patterns and preventing standing waves. On the bottom this is the balls through the mirrors, for the top just putting your equipment on the top disturbs the waves enough to prevent the standing waves.

 

As to cost I just have Online Metals cut a piece of 1/2" aluminum to the size I want. The roller bearing from Engineering are not too bad. The mirrors are a couple dollars a piece from Amazon.

 

There are some issues with this system, number one is cables. The plate has to be free to move on the bearing, thus you need very flexible cables, "fire hose" cables will not work with this! If you put a device with a user interface (preamp with knobs, buttons etc) you don't want "stiff" controls, particularly push buttons or slides that take a lot of force. Rotating controls don't seem to cause a problem.

 

Because of the cable issue i wound up making my own very flexible cables for most things. The improvement in system sound is such a big improvement it was worth it trying to get flexible cables.

 

John S.

[JohnSwenson]

21 hours ago, HumanMedia said:

I currently have the EtherRegen and upstream router and one circuit and the downstream UltraRendu and DAC on another circuit on a balanced power transformer.

 

If I were to go from the upstream router via an optical connection into the etherRegen, could this change which circuit the EtherRegen should be placed on? With an optical input, could it be better moving the EtherRegen to the same circuit as UltraRendu and DAC?

 

Also, whilst optical is an electrical disconnection from upstream, the optical transceivers must generate noise/RFI of their own, so should the EtherRegen be treated differently when using the optical input?  Greater distancing from other components? Different grounding strategy?

 

Any suggestions, advice or experiences appreciated.

With the A side connection via optical there is no inherent reason why either power connection should make a difference.  IF it is easy to do so I would still keep the ER on a different circuit than the uR or DAC, just in case there is some small interaction between power supplies. The ER power supply connects to the A side so it seems to make sense to keep it on the same circuit as what is driving it IF it is easy to do so.

 

If you want to put what is driving the A side 200 feet away and have the ER next to the uR, then go ahead and power the ER from the same circuit. But if you have both circuits near where you want to put the ER, then go ahead and put the ER on the the circuit not powering the uR.

 

John S.

[JohnSwenson]

6 hours ago, chungjh said:

I put a heat sink on top of ER and it brought down the temperature significantly--down to just warm.

The ER was designed to run in the range 40C - 60C, so if you have cooled it off so the case is below 40C you will most likely not be getting the best sound it is capable of giving you.

 

John S.

[JohnSwenson]

50 minutes ago, hemflaw said:

Posting here in case anyone else has experienced something similar: 

 

I got one of the early-ish shipping EtherRegens. Have used with no problem with the original supplies.

 

Baseline setup: consumer router > in-wall CAT7 to wall jack > bluejeans ethernet cable > ER (factory power brick) dirty side > ER clean side > audioquest Cinnamon ethernet > Antipodes EX > USB > Antipodes P2 reclocker > HDMI > DAC > analog components.....

 

In the most recent working setup, the ER factory power brick was connected with a Van den Hul MainsStream, connected to a PS Audio P5 regenerator. The Antipodes and other stuff is also connected to the PS Audio P5, all of which shouldn't matter here.

 

 

 

PROBLEM: A month or so ago I got a used Uptone Audio UltraCap LPS1.2. It came with the original wall wart and an up-spec cable ('Ghent GAC4 Gotham JSSG360 DC lead'). As with the ER factory power supply, I connected the LPS 1.2 with a Van den Hul MainsStream, plugged into a PS Audio P5 regenerator.

 

I did the research and set the voltage to 12. (If this is wrong then I am definitely misreading whatever posts I found in the EtherRegen thread)

 

Connecting it up, all the lights behave as you'd expect, the LPS goes from red to green. All the lights come on on the EtherRegen, as normal.

 

I get ethernet link and traffic lights on the EtherRegen clean and dirty side.

 

But with the new power supply in (and not other changes to the config described above) I simply cannot access (via file sharing, or Roon, or ping) my Antipodes EX. I tried lots of rebooting, re-connecting etc., pain I won't recount here. Throughout the troubleshooting, the power cycle lots on the LPS and the power and ethernet lights on the ER worked as expected, but I got no connectivity.

 

Troubleshooting performed:

- When I remove the ER entirely and connect ethernet from my in-wall jack direct to the Antipodes EX it works immediately. 

- When I replace the standard ER power supply, the ER lights come on as expected, and I have connectivity within 30 seconds or less.

 

 

Any help appreciated ... I can't really go back to the guy I bought it from as the LPS appears to work, but... things aren't working.

You are correct, 12V should be the optimal voltage from LPS-1.2 to ER. 9V should also work, did you try that?

 

One specific difference is the SMPS that comes with the ER has the negative output connected to the safety ground of the AC mains plug, the LPS-1.2 output is isolated from the safety ground. There is a ground screw on the ER which can be used to connect a safety ground if you have an issue with this. Although if your system does not work AT ALL, and this fixes it then you have some other issue in your system which you might want to track down. (usually related to stuff done on USB which prevents proper ground connection, so the only path is safety ground, which is not necessarily the best thing to do)

 

To use the ground screw you need a "ground plug" which looks like a regular mains plug, but just has one wire coming out which is connected to the safety ground pin. The end of this wires gets wrapped around the ground screw. Amazon has some without the wire but has a banana jack, you will then need a banana plug to spade wire (Amazon has these under turntable ground wire).

 

Give this a try and see if this fixes the problem.

 

John S.

[JohnSwenson]

11 minutes ago, Theobetley said:

Can an original ER owner get the new firmware update?

Go to the UpTone website, then go to the Blog section. The top post is about the EtherREGEN and contains a link to the firmware update zip file. The instructions for updating and actual firmware file are in the zip. This is only necessary for ERs delivered in November of 2019.

 

John S.

[JohnSwenson]

4 hours ago, jamesg11 said:

Yes, I’m an isoRegen stayer!

 

Re the use of the js-2 on both macmini & etherRegen - back somewhere is advice from Superdad that isolation is maintained in my case by flipping the etherRegen around, ie modem ethernet into B-side & then A-side thru to dac etc.

I powered both the ER & dac with the 2 js-2 dc outputs (& I used 2x lps1.2s to power uRendu & isoRegen) - I assume this logic applies to your situation ...

The JS-2 is isolated from the safety ground BUT the two outputs share their negative rails. The power to the ER goes into the A side. Thus powering the ER and the DAC from the same JS-2 is defeating the moat of the ER but also the moat of the IsoRegen.

 

John S.

[JohnSwenson]

4 hours ago, Ricardo007 said:

For users of double or triple stack of etherregens:

I am master clocking the last etherregen close to te streamer.

have you positive impact from masterclocking also the etherregens upstream?

You have to be careful with doing that. If you are getting the clocks for the different ERs from the same clock box, you may be bypassing the ER moats by doing this. Some clock boxes have fully isolated outputs, but many do not, the grounds of all the outputs are tied together.

 

John S.

[JohnSwenson]

11 hours ago, Jud said:

IIRC, John Swenson and many others say grounding boxes don’t/can’t work, so perhaps no side and save your money is best. But up to you, of course.

The Entreq type boxes are band-aids for leakage problems, properly setting up an ER and power supplies is a real solution. You definitely do NOT want to use both together.

 

They are in fact antennas, most of the signal is actually picking up line frequency (50/60Hz) which if winds up being out of phase with your leakage will tend to cancel out some of the leakage. Most of the complexities in the boxes wind up filtering out the RF stuff. This type of canceling is not guaranteed, it is very system specific. If you have a system using these and you have wound up tuning so you DO get this cancellation (remember this is done by deliberately injecting line frequency noise into the system!), adding an ER will just make things worse because now the injected noise has nothing to cancel out with.

 

There are other types of boxes which actually feed the safety ground around in a very effective way, these are perfectly fine to use with an ER.

 

John S.

[JohnSwenson]

11 hours ago, GMG said:

Very interesting John 

can you give an example for those“other types of boxes”

I don't remember any of the names, I don't have them myself but have seen people here using them. They are NOT necessary for proper operation of an ER, but they don't hurt it either.

 

John S.

[JohnSwenson]

21 hours ago, Abolive said:

Hi guys,

Running the ER through copper for now, but I would like to try fiber. Can I use any SFP said to be Cisco compatible with a Meraki Ms220? I ask this as this model is getting old and the Cisco specs may have changed.

Thanks!

The SFP "compatibility"  is a number burned into a memory in the module. Different manufacturers have different "Manfacturer ID" numbers. A Cisco switch will look for that number, and if it is not a Cisco number, it won't connect.  It has nothing to do with protocols etc. So as long as the module you buy has a "Cisco" number, you are fine. It is probably best to get two modules so you have the same one for the EtherREGEN. It's not required, but if both are the same you don't have to worry about a mismatch.

 

John S.

[JohnSwenson]

6 hours ago, kennyb123 said:

 

My understanding is the connector can be metal as long as the shield is floating at one end so as to avoid offering a path for leakage current.

There are three things possibly involved here:

ground loops

low impedance leakage loops

high impedance leakage loops

 

Ground loops have been around for a long time and are well known. This is when you to boxes, both with safety ground connections, connected to outlets that have significant amounts of mains wire between them. Normal current running through the hot and neutral induce a voltage onto the safety ground going along with them. If there is a large difference in cable length between outlets, or one branch has a high current load (power amp, air conditioner etc) this induced voltage between the two outlets can be significant which causes current to flow through the cable between boxes. This current is low impedance line frequency so the transformers in Ethernet box WILL prevent it from going between boxes, UNLESS the cable is shielded and connected on both ends, you then can develop a ground loop. No shielding, or shielding not connected o both ends, breaks the loop. Note that this won't happen between devices connected to the same power strip or outlet (duplex outlets almost always have the same safety ground wire). In order for a ground loop to form you must have at least two boxes connected to safety ground (third pin).

 

Leakage loops are a property of power supplies, and DON'T depend on safety ground connections. You can develop them even if all boxes have two pin connections to the mains. You can have them even if both boxes are connected to the same power strip.

 

Low impedance leakage is a property of LPSs and part of the leakage for SMPS. It IS stopped by Ethernet transformers. So unshielded or shielding not connected at both ends WILL stop this type of leakage.

 

High impedance leakage is only a property of SMPS, it is NOT stopped by Ethernet transormers, so for THIS type of leakage it does NOT matter if the there is connected shielding or not. It is getting through anyway. It CAN be stopped by shunting it to safety ground, which only works for this type of leakage. Note this is safety ground, NOT actual earth connection, it doesn't matter whether the safety ground is connected to a ground rod or not.

 

Unfortunately all of this makes it incredibly difficult to make simple always applicable rules. Fully connected shielding by itself, never makes any of this better is any way. So avoiding it is always a good bet. The dielectric (fancy word for insulation) used between the wires in pairs (note NOT the jacket), CAN make a big difference, unfortunately many of the cables that use the best dielectrics are also fully shielded. So frequently it is hard to get the really best dielectrics without getting the connected shields as well. It CAN be done, but not very often. There is no way to know in advance whether the goodness of the very good dielectric is larger than the badness of a fully shielded cable, THAT is very system dependent.

 

Unfortunately, no simple rules.

 

John S.

 

 

 

 

[JohnSwenson]

53 minutes ago, Rsbrsvp said:

Forgive me for my ignorance, but why not get a good cat 8 cable and remove the metal shield from one side?

Of course you are free to do anything you want. Buying a CAT8 and modifying to cut the end to end shield connection can certainly be done.

 

But just because something says it is CAT8 does not necessarily mean it has really good dielectric, some do , some don't.

 

John S.