Objective-Fi Optical Networking & SFPs

[Superdad]

7 minutes ago, plissken said:

...just like Alpha Audio on YouTube did when they tried six different Ethernet Cables.

 

And that was the silliest thing I ever saw. They (and you via your extracting the audio from the video) were expecting comparison of Ethernet cables to be valid via microphone recording through some unknown ADC, then encoded/compressed into a YouTube video. Unbelievable--and surely not "objectively" valid in the least 

[Superdad]

23 minutes ago, ray-dude said:

 

@Superdad without asking you to divulge anything proprietary, did you or John look into any of these things when you were designing and prototyping the ER?

 

Hi Ray: 

We don't include any SFP transceiver with the EtherREGEN and have not dissected and measured ground-plane noise or looked at the signal integrity eye-pattern for various fiber-optic modules.

 

One thing I will point out--which I think you might find interesting--is something sort of obvious but overlooked:

All Ethernet RJ45 copper connections go though both a set of transformer cores (typically 2~8 tiny wound round cores, though for EtherREGEN we use 12-core-per-port magnetics) and PHY transceiver circuitry (mostly these days built into the Ethernet switch chip, but for some switches a discrete PHY chip, per port or grouped, is used--ala the old Cisco Catalyst 2960s, likely one of the things that made them special).

And the signals for SFP cages are always wired directly to the switch chip via the processor's SGMII interface (or even QSGMII or XGMII for much higher speeds--though those are not via SFP cages). Aside from that direct interface perhaps not activating as much circuitry/generating ground-current noise/clock-threshold jitter inside the chip, SGMII is also an LVDS interface, and that carries some advantages.  

Lastly, most good switches will dedicate a 3.3V regulator to provide power to whatever SFP transceiver is plugged into the cage (as we do with an LT3045 just one centimeter behind the EtherREGEN's SFP cage).

 

--Alex C.

 

P.S. By the way, @plissken's first name is Mark not Paul. (And over at ASR he is Jinjuku; various other names elsewhere...)

[Superdad]

15 hours ago, kennyb123 said:

@Superdad any chance you can summarize this for me?  It sounds like you are saying that one interface has an advantage over the other, but I’m unfamiliar with some of these terms so I’m not able to interpret which is better and why that’s so.

 

Mainly I was trying to bring some facts to the discussion of SFP modules, pointing out that there are factors and differences at play besides just the optical transceiver. Some of those might be an advantage favoring the use of optical, some of them might instead favor--or at least influence interaction (and sonic differences)--towards copper.

 

Nothing definitive from me. And while @JohnSwenson would probably have much greater insight than I, he is rather heads-down in new projects for both UpTone and Sonore, hence you don't see him posting much lately. 

[Superdad]

18 hours ago, NoNaim said:

The ADOT, Melco FMC is still very new so it doesn't seem like too many people have it in their systems though.

I guess I just don’t get it. From the photos it is easy to see that this “new” FMC is just an off-the-shelf box—with a 30-cent crystal and nothing at all in the way of high-quality voltage regulation—with a different brand label.

 

A bit like how it turned up that the ThunderData/SilentAngel Bonn/NuPrime/English Electric switches are all nothing more than a $20 ZyXEL GS-108B v3 with an unknown OXCO and a fancier case.
https://www.aktives-hoeren.de/viewtopic.php?f=39&t=11581

https://audiophilestyle.com/forums/topic/62588-uptone-ether-regen-english-electric-8switch-comparison/?do=findComment&comment=1125616

The Sonore opticalModule Deluxe is a from the ground-up design—with a bill-of-materials cost easily 5x this ADOT unit.

[Superdad]

15 minutes ago, NoNaim said:

Actually, while you are on. I was also considering the etherRegen but I have a couple setup questions.

There are a number of issues—relating to preserving the benefits of the EtherREGEN’s active differential isolation “moat”—both with regards Ethernet cable connections and power supply “ground” domains.  Rather than my diverting this thread, how about you contact me directly via our web site? Just be prepared that I am going to ask you for a current system diagram (hand-drawn is perfectly fine) as I am a visual person and trying to follow text of partial system descriptions never works for me or our clients.

Thanks!

[Superdad]

8 hours ago, Abolive said:

FAI Box ->TP Link mc220l -> Zyxel  -> EtherRegen -> streamer 

Why not go optical straight from the TP-Link MC220L to the EtherREGEN?  What is this Zyxel box you intend to insert between them?