EtherREGEN: The long development thread. [Some Gen2 dev. pics and update starting on page 92.]

[Superdad]

4 minutes ago, rickca said:

Does your distributor have the required quantities of the right part?

 

Oh yes, about 1,500 of them at the moment.  

[rickca]

44 minutes ago, Superdad said:

Of course this is why we ALWAYS run pre-production boards!

Getting a board of this complexity 100% right on the first shot must be a tremendous challenge.

[Superdad]

29 minutes ago, rickca said:

Getting a board of this complexity 100% right on the first shot must be a tremendous challenge.

 

Well it's mostly way above my brain-grade.  I just try to keep up and act as a sounding board, double-check, and sometimes suggest an alternate direction to take. Luckily John lives and breathes this stuff and really enjoys it.  

[Except when he has to bang his head against a wall for weeks on something that should just work. Typically involving the programing or register setting of some complicated yet poorly documented chip. I think the giant companies who use some of these parts must have enough clout that they get the engineers at the chip companies to assist with the project when their own teams get stuck.  We have no such connections, and we don't have a "team" of engineers.  So some problems take longer to solve...]

[struts]

8 hours ago, Superdad said:

Our board house reads the pin assignments this way (maybe the pin-1 dot is stupidly on the bottom of the part?):

 

And here is how the bare 6-layer PCBs we just paid a lot to have a few made were run:

 

Ugh!  

Luckily the boards were never populated and sent to us. If they had something would have made some nice smoke immediately. We would have been scratching our heads and out another pile of money.

 

You couldn't just mount this part on the underside of these few boards?

[xtraktz]

Hi @Superdad

 

What is the best way to integrate etherRegen into my system? Now I have Asus router, it does not have SFP port. My music streamer is connected directly to the ASUS router via ethernet, the NAS is also connected to router. I can change my router to a router with SFP (e.g. Zyxel Keenetic Ultra) it's not a problem. 
Will I get improvements in such a scheme: my new router with SFP -> etherRegen's SFP -> etherRegen's isolated pure LAN port ->  my music streamer? 
Or is an enough old router to connect an Ethernet cable to a etherRegen's dirty LAN and from pure LAN to a streamer?

Where is the best way to connect the NAS? To router’ LAN or to etherRegen's dirty LAN port?

 

thanks!

[Superdad]

10 hours ago, struts said:

You couldn't just mount this part on the underside of these few boards?

 

No.  It is a 6-layer PCB.  What is on the bottom has no relation to what is on the top. 

[struts]

50 minutes ago, Superdad said:

 

No.  It is a 6-layer PCB.  What is on the bottom has no relation to what is on the top. 

 

Maybe just mount the part itself upside down??

[Superdad]

10 hours ago, xtraktz said:

What is the best way to integrate etherRegen into my system? Now I have Asus router, it does not have SFP port. My music streamer is connected directly to the ASUS router via ethernet, the NAS is also connected to router. I can change my router to a router with SFP (e.g. Zyxel Keenetic Ultra) it's not a problem. 
Will I get improvements in such a scheme: my new router with SFP -> etherRegen's SFP -> etherRegen's isolated pure LAN port ->  my music streamer? 
Or is an enough old router to connect an Ethernet cable to a etherRegen's dirty LAN and from pure LAN to a streamer?

Where is the best way to connect the NAS? To router’ LAN or to etherRegen's dirty LAN port?

 

I think that our inclusion of an SFP cage has confused many people. Use of optical into--or out of--EtherREGEN is not required to obtain best performance.  The whole point of all the isolation and reclocking techniques we are using (in dual domains) is to make most of the upstream stuff not matter.  Other than the complete galvanic isolation that optical offers going into the EtherREGEN (which we duplicate going across the moat), there is likely no advantage to running optical into it.

 

If you happen to have a router with an optical port and have already run many feet of optical cable to your music system rack, then sure, use the optical port of the EtherREGEN.  But don't go out of your way to run optical if you do not already have it.  And of course for the few people who have a endpoint with optical input (Sonore opticalRendu or perhaps SolidRun ClearFog), one can sort of turn around the EtherREGEN and feed that DAC-connected endpoint from the optical cage.

 

Now to more directly address your questions abut use of EtherREGEN in your set up. We suggest:

a) You place the EtherREGEN nearby your streamer (which is connected to your DAC right?), and run a short (2-3 foot) Ethernet cable of very good quality (BlueJeans CAT6A is quite nice) from the lone 'B'-side port of the EtherREGEN to your streamer;

b) Run any sort of long Ethernet cable from your Asus router to one of the 4 'A'-side ports of the EtherREGEN (cable does not have to be special at all);

c) After you have done the above, you can compare if having your NAS attached to one of the other 3 of the EtherREGEN's 'A'-side ports sounds any better than leaving it attached to your Asus router.

 

By the way, because the EtherREGEN is mostly symmetrical on both sides of its moat--same ultra-low-jitter clocking, differential flip-flops, ultra-low-noise regulators on everything--we no longer refer to any "clean" or "dirty" side.  (I need to update the first post of this thread to reflect that.) Which is not to say that there is zero difference between the sides: The 'A' side has four Gigabit copper ports and one Gigabit-ready SFP cage.  The 'B' side has a lone 100Mbps copper port.

[Superdad]

30 minutes ago, struts said:

Maybe just mount the part itself upside down??

Huh? That's very funny. 

[austinpop]

3 minutes ago, Superdad said:

By the way, because the EtherREGEN is mostly symmetrical on both sides of its moat ... The 'A' side has four Gigabit copper ports and one Gigabit-ready SFP cage.  The 'B' side has a lone 100Mbps copper port.

 

So if you have multiple devices you want to connect on the clean side, you could run your "dirty" router to your B port.

 

Which presents a Shakesperean dilemma - to 'B' or not to 'B': that is the question. 

[Superdad]

11 minutes ago, austinpop said:

So if you have multiple devices you want to connect on the clean side, you could run your "dirty" router to your B port.

 

Aside from having just stated that there is not a "clean" side and "dirty" side, what you propose is quite the opposite of what we recommend.

The #1 consideration that every EtherREGEN user should start with is to attach the DAC-attached endpoint by itself to the 'B' side copper port.  

 

Second choice--only because multiple devices on the same side of the moat is not as ideal--is to feed the EtherREGEN from upstream network via its 'B' side port, and then attach your "audio" devices to the 4 copper ports (and 1 SFP port) on the 'A' side.

[austinpop]

20 minutes ago, Superdad said:

 

Aside from having just stated that there is not a "clean" side and "dirty" side, what you propose is quite the opposite of what we recommend.

The #1 consideration that every EtherREGEN user should start with is to attach the DAC-attached endpoint by itself to the 'B' side copper port.  

 

Second choice--only because multiple devices on the same side of the moat is not as ideal--is to feed the EtherREGEN from upstream network via its 'B' side port, and then attach your "audio" devices to the 4 copper ports (and 1 SFP port) on the 'A' side.

 

Hi Alex,

 

I hope you didn’t take what I wrote as a criticism? It wasn’t. Admittedly I enjoyed making a little joke, but it’s actually a serious consideration, and I wasn’t being gratuitously facetious.

 

Maybe because I’m a reviewer, I often have multiple DACs/endpoints on hand at any given point in time. For example, I am currently reviewing a piece through both the USB and Ethernet input. So I want to use the clean side of the “regen” switch to connect both to the the DAC-attached endpoint and to the DAC directly. And then there could be other endpoints.

 

So I can see a lot of value in using the multiport side of the switch as the clean end. 

[Superdad]

1 minute ago, austinpop said:

So I can see a lot of value in using the multiport side of the switch as the clean end. 

 

Sure, that’s fine—since both sides are very “clean.”  As long as you are crossing the “moat” from one side to the other, the benefits of our special active isolation, ultra-low-hirer differential flip-flops, and femto clocking will be obtained. 

And even on the multi-jack side we made a number of efforts to passively isolate the ports from one another (12-core per port magnetics and center-tap grounding and capacitors).

 

The main point I was trying to make to you is that putting an inferior switch between the EtherREGEN and whatever audio endpoints will degrade the signal integrity and pollute the clocking. 

[austinpop]

1 hour ago, Superdad said:

The main point I was trying to make to you is that putting an inferior switch between the EtherREGEN and whatever audio endpoints will degrade the signal integrity and pollute the clocking.

 

Now Alex, why on earth would I - of all people - even dream of doing that?

 

My point to you was that there are legitimate use cases that need multiple clean ports. Here's the picture from an impending review.

 

 

The EtherRegen could slot into where the SOtM switch currently is. Do note, from the picture: there is one "dirty" input, and 2 "clean" outputs. 

[Superdad]

9 minutes ago, austinpop said:

Now Alex, why on earth would I - of all people - even dream of doing that?

 

LOL.   Of course I know you know that your's is something of an extreme case.  But considering you could almost purchase 3 EtherREGEN units for the price of one SOtM switch I am not too worried... 

[austinpop]

1 hour ago, Superdad said:

 

LOL.   Of course I know you know that your's is something of an extreme case.  But considering you could almost purchase 3 EtherREGEN units for the price of one SOtM switch I am not too worried... 

 

Not that extreme. Just one EtherRegen could replace the SOtM switch in my picture, with the same PSU and the same 10MHz reference clock. A shootout just begging to be done.

 

Hint, hint.  

[LewinskiH01]

4 hours ago, Superdad said:

 

The 'A' side has four Gigabit copper ports and one Gigabit-ready SFP cage.  The 'B' side has a lone 100Mbps copper port.

 

What is the significance of having Gigabit vs 100Mbps copper ports in the context of audio transmission/reproduction such as how this unit is meant to be used?

[Superdad]

39 minutes ago, LewinskiH01 said:

What is the significance of having Gigabit vs 100Mbps copper ports in the context of audio transmission/reproduction such as how this unit is meant to be used?

 

The new low-jitter, differential, active digital isolators we use are not fast enough for Gigabit speed. So the lone 'B'-side port is 100Mbps. Since 100Mbps is plenty fast for all audio endpoints there should not be any issue for any normal use case.

[LowMidHigh]

SuperDad, 

 

How long a cable can I run safely from the  A side to a Mac Mini dedicated to Netflix streaming? It's about 20 meters from the switch? Or would you recommend getting a second switch? 

 

Thanks! 

[marce]

On 7/9/2019 at 9:36 AM, struts said:

 

You couldn't just mount this part on the underside of these few boards?

Its SMD!!!

[Jud]

2 hours ago, marce said:

Its SMD!!!

 

Well, the underside's a surface...  😉

 

Apologies for the OT, but just curious, have you ever seen two-sided SMD? If not, is there a very good reason not to do it?

[marce]

I do double sided placement designs every day, no reason not to do it (though it does have an impact on cost and ease of assembly)... But unlike PTH components the pads for SMD components only exist on the outer layers of the PCB so you can't get to the pads from the opposite side, and you can't drill through the PCB without causing shorts.

A PCB is a 3D entity, with numerous layers of copper patterns forming the circuitry, the simplest usually having 4 these days, more complex ones 10-16 and very rarely up to 28 layers (the most I have ever done!), these layers connected by either standard plated through vias or HDI via's.

https://en.wikipedia.org/wiki/Via_(electronics)

https://en.wikipedia.org/wiki/Microvia

 

For fun the design I am doing has numerous power supplies, the fun part is getting rid of heat, heat sinks don't work very well in the vacuum of space and no convection currents to cool the PCB!!! In this instance the hot parts will have single sided placement with a metal assembly clamped to the opposite side of the board, lots of thermal vias to get the heat to where we want it...

[mansr]

1 hour ago, Jud said:

Apologies for the OT, but just curious, have you ever seen two-sided SMD? If not, is there a very good reason not to do it?

Double-sided PCBs are very common. The main advantage is smaller size. The disadvantage is more complicated (and thus expensive) assembly since it requires two passes through pick-and-place and reflow. As always in engineering, it's a trade-off.

[Superdad]

13 hours ago, LowMidHigh said:

How long a cable can I run safely from the  A side to a Mac Mini dedicated to Netflix streaming? It's about 20 meters from the switch? Or would you recommend getting a second switch? 

 

20 meters to the EtherREGEN is no problem at all. I believe the limit is 100 meters (328 feet) for CAT 5/5e/6 cable between routers/switches.

[Bernstein]

@Superdad

Do you have sind picture or concept pics of the outside?

What is the heat dissipation of the unit? Can it used in a closed enclosure (cabinet).