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

[rncasper]

Been fun to follow this thread--I too have been eagerly awaiting the EtherREGEN. I'm wondering about the SMPS provided--would you suggest it be plugged straight into the wall, as you do with the SMPS you send along with the LPS 1.2? And still interested in whether or not an LPS makes a difference. Thanks.

[rncasper]

21 hours ago, Superdad said:

 

The UpTone-branded 36W SMPS--which is provided as the "energizer"/charging supply for the LPS-1.2 and will also be the stock PS included with EtherREGEN--is slightly unique in that it is internally "ground-shunted."  That is, the outer barrel shell (-VE/"ground") of its DC output is--through circuits in the case--connected to AC mains ground.  The effect of that is to eliminate high-source-impedance AC leakage.  (Note that this does nothing to eliminate the low-source-impedance leakage common to all SMPS units--bad in most, much worse in some.)

Below is why this matters, and also why the recommendation with the EtherREGEN will be to insure that either:

a) EtherREGEN is powered by a power supply whose DC output -VE (outer-shell/"ground") is common to AC mains ground (such as the one we include). [Do not assume that 3rd party linear power supplies are like this--some are and some are not; Some multi-rail supplies have separate diode bridges and transformer secondaries and thus each output ground is "floated". This is easy to test with a continuity/multimeter--with all power disconnected.)

or:

b) If powered by a "floating" supply (one whose DC output -VE/"ground" is not common to mains ground), then the Ground Screw of the EtherREGEN should be used. [And yes, our UltraCap LPS-1.2 is a completely "floated" and isolated supply, so if using it with EtherREGEN the ground screw ought to be used.]

 

Back to why any of the above matters (and to what degree audibly varies--and in the case of EtherREGEN we do not know yet):

@JohnSwenson has measured high-source-impedance leakage on Ethernet cables coming from various other common network gear and computers. This can be pernicious stuff (common-mode AC leakage traveling over DC connections passes easily along both analog and digital connections in our audio systems), and it is desirable to shunt it away.  He measured a bunch of Ethernet switches and found that a few select ones--even a few cheap ones--will, when their DC power supply is shunted (as explained above), not pass AC leakage currents between their ports. 

[Some good posts of John's on leakage--can't find the one on it with the switches right now--here:

https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/?do=findComment&comment=723187 and here:

https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/?do=findComment&comment=735311 (tons of info in that thread)]

 

So in the design of the EtherREGEN we of course wanted to address this. In fact we have done so in several ways. The RJ45 magnetics that we chose for the four 'A'-side Gigabit ports have 12 tiny transformer cores per port. And their center-taps are wired to the ground and to the Ethernet switch chip through capacitors such that we maximize the blockage of leakage passing from port-to-port. And this works best if the unit is grounded (either through the power supply or via the ground screw).

 

But keep in mind that the above is just about blocking port-to-port leakage on the 'A' side. This has nothing to do with the full active digital isolation and reclocking moat--to the 'B'-side port--which makes the EtherREGEN unique in all the world. 

Yet frankly, with all the care we take on the 'A'-side--with all LT3045 voltage regulation, magnetics, and "femto" clocking--EtherREGEN will be a world-class switch even if the 'B' side port is never used!  But the real magic will happen when you cross the moat and use the 'B'-side port to feed your DAC-attached computer/renderer/endpoint.

 

----------

Sorry if I never quite answered your question.  

a) Don't know if plugging the stock SMPS direct to wall or into a "power conditioner" will matter--just be sure it gets a good mains ground;

b) We will all soon find out just how much or how little a good LPS benefits the EtherREGEN.

---------

 

And a quick update (busy day and I've got to get to shipping and other e-mails):

All the EtherREGEN pre-production boards are working great--end-to-end--including the SFP/optical.  John has prepped them all to be ready for user beta-test and he is shipping them down to me today (arriving Friday).  

Because the production cases won't arrive until the beginning of October, I took the milling drawings and a bunch of old LPS-1 front plates to my local machinist.  So the beta units will have end-plates that fit. Of course no silk-screened lettering--though on the 'A'-side the UpTone Audio logo from the LPS-1 faces will still be there, in the exact right spot.

 

Ciao!

--Alex C.

 

 

Much thanks--you did indeed, and then some! And counting down the days for the launch . . .