Optical Network Configurations

[audiom3]

2 hours ago, McNulty said:

If Sonore, Lumin, Hifi Rose etc. are reading this,  maybe they can consider releasing endpoints with SFP+ ports instead of SFP as a next generation of their existing products…

I was really bummed when I bought the Lumin U2 and tried like hell to get any 10G transceiver to work in it (ie. 10G/1G dual rate transceivers).  But alas, the port is just not capable.  What I am able to do in my LHY switch, is use a 10G transceiver (Finisar 1471BTL) sending/communicating with/to a 1318 (1G) inside the Lumin.  Not sure how the jitter/specs work, etc in this bastardized connection.  I know the sound improved over dual 1318s though.  But moving that Finisar 1471 from a Mikrotik CRS309 on an LPS to the LHY SW-10 proved to be a far bigger change in SQ than any other network tweak to date.

[Jud]

2 hours ago, McNulty said:

If Sonore, Lumin, Hifi Rose etc. are reading this,  maybe they can consider releasing endpoints with SFP+ ports instead of SFP as a next generation of their existing products…

 

The Fitlet3's optional optical Ethernet input is SFP+ and works just fine with my 10G system, though internally it is 1G speed. I'm guessing since it works with 10G equipment the input may meet 10G spec in terms of jitter, but I'm not sure of that.

[Psilonaught]

3 hours ago, McNulty said:

If Sonore, Lumin, Hifi Rose etc. are reading this,  maybe they can consider releasing endpoints with SFP+ ports instead of SFP as a next generation of their existing products…

 

Why on earth would a streamer need SFP+  bandwidth 🙄

[The Computer Audiophile]

1 minute ago, Psilonaught said:

 

Why on earth would a streamer need SFP+  bandwidth 🙄

I hope your products stil use 100 Mbps, becuase that's all you need. 

[Jud]

23 minutes ago, Psilonaught said:

 

Why on earth would a streamer need SFP+  bandwidth 🙄

 

You might want to read the thread a bit. There's a good practical engineering reason 10G equipment might be nice to have, though not necessary, and it isn't bandwidth.

[audiophilac]

1 hour ago, audiom3 said:

I was really bummed when I bought the Lumin U2 and tried like hell to get any 10G transceiver to work in it (ie. 10G/1G dual rate transceivers).  But alas, the port is just not capable.  What I am able to do in my LHY switch, is use a 10G transceiver (Finisar 1471BTL) sending/communicating with/to a 1318 (1G) inside the Lumin.  Not sure how the jitter/specs work, etc in this bastardized connection.  I know the sound improved over dual 1318s though.  But moving that Finisar 1471 from a Mikrotik CRS309 on an LPS to the LHY SW-10 proved to be a far bigger change in SQ than any other network tweak to date.

you weren't able to get dual rate 1/10 sfp module working on lumin - what switch did u initially use?

CRS309 or LHY?

[Superdad]

On 5/2/2024 at 10:02 AM, jabbr said:

 

The fast switches already use stuff like this https://www.renesas.com/us/en/products/clocks-timing/femtoclock-low-phase-noise-frequency-synthesizers

 

Those Renesas clock synths are nice, though a bit pricy at $16pc. in quantity, and we don't really need 3 inputs and 8 outputs.  The Silicon Labs (now Skyworks) synth we use in the EtherREGEN has phase jitter specs equal to the Renesas, but the Analog Devices synths we are moving to for EtherREGEN Gen2 have dramatically lower phase noise that any of the others.

So one does not need to go to 10G/100G switches to get that level of clocking performance. 

 

Of course this leaves out the noise/jitter that gets embedded by optical transceiver modules (differences in which I believe is the primary cause for the variations folks here between SFP brands/models; and why Finisars generally end up as preferred).

 

 

[audiom3]

7 minutes ago, audiophilac said:

you weren't able to get dual rate 1/10 sfp module working on lumin - what switch did u initially use? LHY?

Peter confirmed that no 10G module would work in any Lumin product.  But I still had to try everything, since I have tons and tons of transceivers lying around...  I couldn't get the 10G SFP+ to work in the Mikrotik CRS309, so I bought a cheap, generic 1G SFP switch (Bindardt?) and the 1471BTL worked fine in it.  But no getting around a 1318 transceiver in the Lumin U2.

[audiophilac]

Just now, audiom3 said:

Peter confirmed that no 10G module would work in any Lumin product.  But I still had to try everything, since I have tons and tons of transceivers lying around...  I couldn't get the 10G SFP+ to work in the Mikrotik CRS309, so I bought a cheap, generic 1G SFP switch (Bindardt?) and the 1471BTS worked fine in it.  But no getting around a 1318 transceiver in the Lumin U2.

with LHY switch, did you try the opposite way?

1471 at Lumin, 1318 at LHY

[audiom3]

1 minute ago, audiophilac said:

with LHY switch, did you try the opposite way?

1471 at Lumin, 1318 at LHY

Yes, tried.  The 10G modules won't 'click' into the Lumin U2 as I believe they have a few more contacts or something which makes them just a tad wider at the contact point?  So I just tried to gently push it in as best I could, to no avail.

[Superdad]

1 hour ago, audiom3 said:

The 10G modules won't 'click' into the Lumin U2 as I believe they have a few more contacts or something which makes them just a tad wider at the contact point?

That is incorrect.  SFP and SFP+ transceivers have exactly the same PCB width/contacts.

[audiom3]

Just now, Superdad said:

That is incorrect.  SFP and SFP+ transceivers have exactly the same PCB width/contacts.

Ok, thank you. I put the question mark because I wasn't sure. I don't know why the 10G modules refuse to lock into the Lumin U2 then. 

[SQFIRST]

6 hours ago, McNulty said:

If Sonore, Lumin, Hifi Rose etc. are reading this,  maybe they can consider releasing endpoints with SFP+ ports instead of SFP as a next generation of their existing products…

That seems like a sensible approach doesn't it? It may pose some engineering complications with regards to sensitive audio design. If that is not the case then it is a no brainer. Just from an adoption standpoint, there will be resistance as the norm has been 1G and lower up until now. Add pricing increase to that, the case becomes quite difficult. But certainly a ground breaking design waiting to happen.
 

2 hours ago, Superdad said:

the Analog Devices synths we are moving to for EtherREGEN Gen2 have dramatically lower phase noise

This is great to hear as the benefit from the ER1 is audible and seems attributable to the phase noise lowering aspect.

 

2 hours ago, Superdad said:

this leaves out the noise/jitter that gets embedded by optical transceiver modules (differences in which I believe is the primary cause for the variations folks here between SFP brands/models; and why Finisars generally end up as preferred).

Which brings us back to the earlier discussion about the advantage of using 10G and higher protocols to remove jitter.

The point being that a concerted effort targeting digital 'noise' removal, which could include multiple specialized solutions, maybe needed for quality output. One approach does not have to negate the other. Also, this type of effort may not be for everyone as people have differing levels of patience, idea of fun and interests. 

 

1 hour ago, audiom3 said:

I don't know why the 10G modules refuse to lock into the Lumin U2

I have the X1 and did notice the same issue and narrowed it to the transceiver locking mechanism. The Lumin did not allow for the lock to open properly which prevents the module from seating into the cage. I did get a generic 10G to work with it but did not like the performance. It is a good idea to not try to make it work and heed Lumin's recommendation.

[jabbr]

5 hours ago, Superdad said:

 

Those Renesas clock synths are nice, though a bit pricy at $16pc. in quantity, and we don't really need 3 inputs and 8 outputs.  The Silicon Labs (now Skyworks) synth we use in the EtherREGEN has phase jitter specs equal to the Renesas, but the Analog Devices synths we are moving to for EtherREGEN Gen2 have dramatically lower phase noise that any of the others.

So one does not need to go to 10G/100G switches to get that level of clocking performance. 

 

Of course this leaves out the noise/jitter that gets embedded by optical transceiver modules (differences in which I believe is the primary cause for the variations folks here between SFP brands/models; and why Finisars generally end up as preferred).

 

 

 

👏 👏 👏 Yes yes, my point is that these devices are actually more important than the oft quoted OXCO regarding ultimate jitter. Analog Devices is a great company of course and the reported jitter on some of these devices is crazy low.

 

Its not that you have to go to 10G/100G rather that these specs require compliance testing assuring that the devices behave. There is nothing preventing a specific 1G switch/device from being implemented to achieve the behavior ie stressed receiver eye pattern of the 10G spec. If you have a specific 1G device which you love the "SQ" of then you are all set. Nor is there a guarantee that any 10G switch will sound better to you. 

 

and as you further note, the clock is only part of the entire jitter budget. the 10G/100G and all the newer specs don't need to focus on requirements for each individual component because the specifications are end-to-end. specifically the specs require that the receivers accept a marginal input and clean it up.

 

in the 10G/100G (i.e. newer) world the end user need not care about which clocking device, crystals etc are used nor can they change them. external clock inputs don't exist in the lowest jitter switches (and of course these switches aren't intended for the home user)

[jabbr]

2 hours ago, SQFIRST said:

That seems like a sensible approach doesn't it? It may pose some engineering complications with regards to sensitive audio design. If that is not the case then it is a no brainer. Just from an adoption standpoint, there will be resistance as the norm has been 1G and lower up until now. Add pricing increase to that, the case becomes quite difficult. But certainly a ground breaking design waiting to happen.

 

Its entirely unclear to me that the endpoints need to handle 10G ethernet given the assumption that the switch device which is capable of 10G would presumably perform in a similar fashion when operating at 1G

 

2 hours ago, SQFIRST said:

 

Which brings us back to the earlier discussion about the advantage of using 10G and higher protocols to remove jitter.

 

Its not the 10G protocol which removes jitter, rather the specification which requires end-to-end testing with a stressed receiver i.e. a crappy input and clean output. The implementations are required to remove jitter

 

2 hours ago, SQFIRST said:

The point being that a concerted effort targeting digital 'noise' removal, which could include multiple specialized solutions, maybe needed for quality output. One approach does not have to negate the other. Also, this type of effort may not be for everyone as people have differing levels of patience, idea of fun and interests. 

 

Again all compliant 10G+ switches remove jitter and all fiberoptic switches remove common mode noise. You don't need to worry about this. 

 

2 hours ago, SQFIRST said:

 

I have the X1 and did notice the same issue and narrowed it to the transceiver locking mechanism. The Lumin did not allow for the lock to open properly which prevents the module from seating into the cage. I did get a generic 10G to work with it but did not like the performance. It is a good idea to not try to make it work and heed Lumin's recommendation.

 

Its not the 10G SFP which removes jitter though any device attached to the DAC might affect SQ.

[jabbr]

5 hours ago, audiom3 said:

I couldn't get the 10G SFP+ to work in the Mikrotik CRS309

Is the 10G module you tried on the Mikrotik CRS309 compatibility list? Although some lore has developed about certain  SFP modules, they aren't required to work when not on the compliance list. One of the things about having boxes of SFP modules is that you can usually find one that works.

 

[SQFIRST]

1 hour ago, jabbr said:

Its entirely unclear to me that the endpoints need to handle 10G ethernet given the assumption that the switch device which is capable of 10G would presumably perform in a similar fashion when operating at 1G

 

1 hour ago, jabbr said:

Again all compliant 10G+ switches remove jitter and all fiberoptic switches remove common mode noise. You don't need to worry about this. 

 

 

Based on your statements it would seem that the Mikrotik CRS305 is not compliant.

I have been using it to reduce network jitter with 10G end to end. There were other solutions necessary for optimal sound from my 1G endpoint which is a streamer-DAC. 

 

1 hour ago, jabbr said:

Its not the 10G SFP which removes jitter though any device attached to the DAC might affect SQ.

The conversation here was more about the physical issues in seating SFP+ modules in a Lumin and not so much about 10G itself.

 

 

[audiom3]

1 hour ago, jabbr said:

Is the 10G module you tried on the Mikrotik CRS309 compatibility list? Although some lore has developed about certain  SFP modules, they aren't required to work when not on the compliance list.

It wasn't that the transceiver wouldn't work in the 309. It was that it would not work with the CRS309/Lumin combo.  I use Finisar 1471s all over my house. Although a lot less now that I've ridded my AV components of FMCs.

[dbastin]

11 hours ago, audiobomber said:

Thank you @audiom3. Despite all the chatter in this thread about the technical superiority of 10G vs. 1G, there are no comparisons that I've read directly comparing a 10G implementation to an audiophile switch.

 

Actually my system is 1G until the ER, then 100mbps. Technically primitive, but sounds fantastic.😛

For what its worth, I recently compared CRS 305 to ER.

As context, my system/network is very revealing, I can hear differences changing ground wires to the very first device and inserting RJ45 caps in it, and between that device and the endpoint it CRS 305, fibre, ER and wifi to the endpoint, and all cabling is very low noise (>US$1k retail).

 

In the comparison the CRS 305 and ER were powered via a dedicated power source:

 

main switch board > dedicated power line (JPS Labs) > Shunyata Sigma Analog power cable > Shunyata Cyclops > Synergistic Research (SR) Atmosphere UEF Level 3 power cable > W4S PS 1 > SR SX DC cable. 

The devices were sat on a SR Tranquility POD Carbon and grounded via SR HD SX ground cable to SR Active Ground Block SE.

The CRS 305 and ER were here:

 

incoming fibre > mandatory receiver/modem > cable > ER Side B - SIde A > fibre > CRS 305 > cable > Antipodes CX Oladra > cable > WAP (300MB/p) - wifi - > Devialet Pro 440 (I have previously established this wifi connection is extremely good)

 

Initially I basically swapped the order of the ER and CRS 305 to:

 

incoming fibre > mandatory receiver/modem > cable > CRS 305 > fibre > ER Side A - Side A > cable > Antipodes CX Oladra > cable > WAP - wifi - > Devialet Pro 440

 

In my view the ER in this set up was superior, easy to hear but not a huge margin.

 

I tried different configurations with ER and settled on this being best:

 

incoming fibre > mandatory receiver/modem > cable > CRS 305 > fibre > ER Side A

then Side A > CX

and Side B > cable WAP > - wifi - Devialet Pro

 

In my view the ER in this set up is superior to CRS 305 by an obvious and moderate margin.

[dbastin]

7 hours ago, Superdad said:

the Analog Devices synths we are moving to for EtherREGEN Gen2 have dramatically lower phase noise that any of the others.

Yay!

Audio endpoint designers really should include this type of stuff.

[Jud]

Starting to get a little curious about transceivers and had a couple of questions:

 

- Should I expect a SFP+ multimode transceiver labeled as Finisar selling in the ~$20 range to be genuine?

 

- Who's a reliable seller (particularly in the US)?

[Superdad]

52 minutes ago, Jud said:

- Should I expect a SFP+ multimode transceiver labeled as Finisar selling in the ~$20 range to be genuine?

Probably not—unless you find some used ones on eBay.

But why go multimode instaed of single-mode when the two are close to price parity?

 

52 minutes ago, Jud said:

- Who's a reliable seller (particularly in the US)?

Well DigiKey is an authorized and stocking distributor for Coherent (that’s the new name of II-VI Corp., the company that bought Finisar a few years ago). Prices are in the $50-80 range.

https://www.digikey.com/en/products/filter/fiber-optic-transceiver-modules/118?s=N4IgjCBcoEwBxVAYygMwIYBsDOBTANCAPZQDaIAzAGwVxgAMIAuoQA4AuUIAyuwE4BLAHYBzEAF9CVAJyIQKSBhwFiZSnDj16VEIVqb6AVmZtOkHv2FjJ4aXFnR5aLHkIlI5RkxsBaCI4UlV1UPEAAWOAB2L18HZCh%2BAFcVd3IIb0IfCjkFJJS1BmZfGByEvmS3NWNvGx1HAQATLj96CFMuXRB2AE9WXC50bBRxcSA

[jabbr]

9 hours ago, SQFIRST said:

Based on your statements it would seem that the Mikrotik CRS305 is not compliant.

You are confused about what I’m saying. 
10G+ Ethernet compliance testing is specified (in the specification itself) Compliant means it passed the required testing. 

[jabbr]

9 hours ago, audiom3 said:

It wasn't that the transceiver wouldn't work in the 309. It was that it would not work with the CRS309/Lumin combo.  I use Finisar 1471s all over my house. Although a lot less now that I've ridded my AV components of FMCs.

You don’t need to use the same SFP(+) module in the switch and endpoint 

[jabbr]

9 hours ago, dbastin said:

For what its worth, I recently compared CRS 305 to ER.

If you are dealing with copper outputs/networks … there is no reason to think that inexpensive … or any … 10G switches have low common mode noise and SQ can be affected by that … essentially fancy ground loops. 
 

I have done exactly zero testing of 10G switches output using copper to endpoints