I’d appreciate any comments on sound quality from users of Lumin products who employ a LAN optical connection (fibre, spelled the British way). I’ve been using multimode fibre from Sonore, as I once owned the company’s original opticalModule (oM) that came configured this way. When I originally set up the Lumin X1’s fibre connection, I used the oM, but have since moved to fibre implementation via an etherRegen switch. The sound quality, by the way, is terrific.
Recently, though, I’ve been intrigued by some online posters who’ve heard a tangible difference between multimode and single-mode fibre, with the latter purportedly having an uptick in SQ. As you probably know, Lumin is agnostic on the topic, saying that both multimode and single-mode will work. Lumin’s website suggests the use of Corning’s ClearCurve single-mode duplex fibre; there is no multimode fibre recommended, so perhaps that is a small clue. The recommended transceivers are StarTech and 10Gtek. Again, as the transceivers need to match the single-mode fibre, perhaps this is another small clue that single-mode might be preferred.
I can’t recall the exact fibre and transceivers with the original oM, other than the fibre was specified as Sonore-branded systemOptique Certified Fibre-Optic Cable.
Peter Lie, Lumin’s firmware lead and a frequent, valuable contributor to this site, has shared that one dealer who tested the LAN optical connection with the X1 preferred single-mode. Peter has encouraged people seeking the best SQ to test one vs. the other. To that end, I’ve ordered Corning ClearCurve fibre and some matching Finisar transceivers (FTLF1318P3BTL) that have been popular among some online posters. (As a side note, Sonore now recommends Finisar transceivers as an upgrade to their second-edition oM, perhaps another small clue!) As the purchases were quite reasonable, I don’t mind letting them sit on the sideline while I ponder this dilemma, with the potential help of Lumin users!
Hi @Flashman. I run the 1318s in my setup. One pair right after my NUC to convert it’s output to fiber and then I use the other pair from switch to my U2. When I experimented, the difference was obvious. I was using a PS Audio Bridge II card at the time and not only did things sound better, there was less audible hiss present. The Bridge II is a noisy interface but converting to fiber and then adding in the Finisars made it worlds better. Do you have a link to the Corning fiber that you ordered? I’d love to check it out. Thanks.
@Flashman thanks for sharing. I ordered two cables and they’re already out for delivery today! Kind of makes up for their pricey shipping. Not sure if I’ll note any SQ change over my generic cables, but you never know unless you try.
I’m hearing a difference with my new set-up, but since I have new Finisar transceivers plus the Corning ClearCurve fiber, it’s difficult to parse which is contributing more!
1 Like
Torben_Rick
(Torben - A Dane living in Hamburg - Roon Lifer)
6
I had to import “LC-LC Duplex 9/125µm Corning ClearCurve Single Mode Bend Insensitive Fiber Optic Patch Cable” from the US - could not find it in Europe.
Will arrive tomorrow with UPS (Germany).
Torben
2 Likes
Torben_Rick
(Torben - A Dane living in Hamburg - Roon Lifer)
7
Very interesting. I “only” use fiber from the switch to FMC and than short (20 cm) CAT6 cable to streamer/DAC.
Why do you have 2 x FMC in your setup?
Torben
PS: I don’t use Finisar, would probably not work with me Cisco Meraki Go 8 Port Switch (GS110-8-HW-EU). I use StarTech - Cisco Meraki MA-SFP-1GB-LX10 Compatible SFP Module - 1000BASE-LX - 1GbE Single Mode Fiber SMF Optic Transceiver - 1GE Gigabit Ethernet SFP - LC 10km - 1310nm - DDM
Well, my LAN is all fiber optic. So every device that has either a copper input or output has an FMC.
The Intel NUC’s only output is copper. So I use a short run of Supra CAT8 from NUC to a Sonore opticalModule and then the Finisar in that end runs to my main fiber switch near all of the source components. These include my main Win11 workstation, my TrueNAS server and the Intel NUC running ROCK. Then I have a 50’ run of fiber to my equipment area into another Mikrotik switch. Off that switch is another Finisar 1318 to Finisar 1318 installed in the U2’s cage. So really, only one FMC in that whole route. The switches keep the network in fiber optic mode.
I have yet to convert my 50’ run to single mode fiber and I suspect that could also make a slight difference over multi mode cable and transcievers. But all transceivers in my HT and audio media room are Finisar-made. I love them. I even have some 10G transceivers in my Win11 machine’s NIC and my TrueNAS server NIC. This way I can transfer my movies to the server super fast. Music takes seconds so no real notable difference between 1G and 10G.
I’m open to the idea that different SFP modules sound different- would be interesting to hear other impressions if people can compare. I really want to like my optical setup but not quite there yet.
Torben_Rick
(Torben - A Dane living in Hamburg - Roon Lifer)
12
@Hudson - I have tried different setup’s (SFP, multimode, singe mode …) and ended up with this:
I don’t know what connector “LC-LC Duplex 9/125µm Corning ClearCurve Single Mode Bend Insensitive Fiber Optic Patch Cable” has.
If it is Grade B than it is perfect. If not you could also try: “Customized Grade B Duplex Typical 0.12dB IL OS2 Single Mode LC/SC/FC/MU 2.0mm Bend Insensitive Fiber Optic Patch Cable” from
Quality level Grade B /2 according to the IEC 61753-1 standard is currently the highest level.
This is the fs.com link from Lumin website - I bought a few from them (in the past it could take up to 2 weeks to ship, not sure about now): https://www.fs.com/products/68296.html
It was put in the “ultra low loss” category in the past. However, fs.com reorganized the web site so it’s different now.
Every fiber that I got from this link had an individual test report.
Rick, I’m not sure which connectors are on my fibre cable. Looking at the German site and the numbers from Fosco that were provided, I might have Grade C and not the better Grade B. I didn’t realize one could specify various grade connectors with fibre cables. I’ll have to investigate some more. Thanks.
If memory serves me, these figures from your photo are roughly similar to mine from fs.com . I’ll try to find those fs.com test reports next week after the holiday here.
Thanks for sharing. As I’m unclear about how these measurements compare with the connectors on the fiber I purchased, I’ll wait to hear from Peter Lie after the holiday weekend about the similar fiber cables that he bought.
I found this brief explanation: “Insertion loss is expressed in decibels, or dBs, and should be a positive number as it indicates how much signal was lost by comparing input power to output power. In other words, signals always come out smaller than they go in. The lower the number, the better the insertion loss performance – an insertion loss of 0.2dB is better than 0.4dB.”
So, the grade B connector has an insertion loss of 0.12 and the lowest on my connector is 0.20. I’m not sure how that differential might affect performance. I suspect it’s not audible, but who knows?
