Effectiveness of Short Run of Fiber Optic Cable

Hello All,

I’m considering re-configuring my streaming setup with the possible use of fiber optic cable. I just bought an Antipodes CX that I will receive next week. I had originally considered making a long run of FO cable to replace my current long run (about 20 ft.) of generic originally installed 16-yr-old CAT5 cable from switch near router to wall plate in listening room. Unfortunately, making that FO run is just simply not practical, if possible at all. Here is my current setup:

Verizon Fios router (also serves as wifi for iPad and iPhone)—CAT5—>Netgear switch GS-116 (all ethernet connected devices in home are plugged into this, including Mac Mini as Roon Server)—CAT5 to listening room—>Wall Plate—WW Starlight 8 Ethernet—>EtherRegen (stock)—>WW Plat. Starlight Ethernet—>Cary DMS-600 Streamer/DAC.

Since I cannot do the long run of FO to the listening room, I’m thinking of doing a short run from an FMC (placed directly after Fios router) to a dedicated switch placed directly after FMC. The switch would then convert the FO back to Ethernet for the long run to the listening room. It would look something like this (changes in bold ):

Verizon Fios router ( powered by iFi iPower LPS )— WW Ethernet —> FMC —> 1m (or whatever length needed) FO Cable —> Buffalo BS-GS2008 switch (powered by Keces P3) —> WW Ethernet —> Buffalo BS-GS2008 switch (powered by Keces P3) —>CAT5 to listening room—>Wall Plate—WW Starlight 8 Ethernet—>EtherRegen ( powered by Paul Hynes SR5T )—>WW Plat. Starlight Ethernet—> Antipodes CX (Roon Server) —WW Plat. Starlight Ethernet—->Cary DMS-600 Streamer/DAC. The non-audio ethernet devices would be served via a separate ethernet cable run from the Fios router to the Netgear switch. The Netgear switch and all other devices in house with SMPS will get Jemeco LPS.

So my question is: Would it be worthwhile to run an FMC—>1m (or however how long) FO cable from the router into a pair of switches (or just one switch) just to convert it back to ethernet for a 20ft+ run to the listening room? The idea would be to isolate the audio stream from the router and everything connected to the other ethernet run from the router, but I don’t know if this would do the trick. Any other constructive suggestions for the proposed setup are welcome as well.

I don’t think it would do much how you would have it set up. It would have to go between the server and the Cary streamer to do any good. In theory it could potentially improve the sound quality due to complete galvanic isolation of the fiber optic cable, which would then galvanically isolate your server from your streamer. But since the FMC converting fiber back to ethernet has a power source and internal circuitry, that could potentially cause its own noise. But there is a product by Sonore called the Optical Module. They sell a bundle that has two of the optical modules, two of their LPS and their recommended fiber optic cable and SFPs. I think this bundle is part of their “System Optique” system, which is for doing what you are trying to accomplish. Its not cheap though. https://www.smallgreencomputer.com/collections/systemoptique/products/systemoptique-optical-isolation-bundle?variant=16660686241826

The owner of small green computers, @agillis, and the founder of Sonore, @Jesus_Rodriguez, are on this forum all the time. They usually respond to being tagged and they will know way more about this than anyone else will. But check out their products and go from there. Good luck!

Thanks for the reply. I’m familiar with opticalModule. What I am trying to accomplish here is to remove as much noise as possible from the signal before it travels along the long CAT5 run from the router position in my utility room to the the listening room. I am wondering if a short run of FO cable, either at the beginning of the chain or near the end, would be effective. I am also wondering if a long run of FO cable at the beginning does any good if what follows is a 20 feet+ run of generic CAT5 to the listening room is what follows.

How so?


Of course it can generally be done. I am referring to my specific logistical situation.

OK, it seemed like you already had snaked Ethernet cable from your router to your listening room, so fiber would be no different, but you know your logistics.

I had not done the work, it was done during the initial build of the house. I am the original owner and I had the builder run CAT5 to every room in the house. What I am trying to do now is mitigate the noise traveling along that 20ft+ run of CAT5 to the listening room some other way since running FO cable to replace it is not practical, if possible at all.

OK, not looking for an argument, but if you can’t do it any semi-competent electrician can snake cable thru your walls and across multi-levels.

Especially since there is probably a chase for the Ethernet cables already in place.


The CX’s ethernet port is low noise design already so you may be wasting cash especially for such a short run. I would suggest contacting support at Antipodes for an opinion. They have the best support I have ever seen. I am an EX user with the same length of cat5. Completely silent.

Right, I get it, and my answer was that a run from the server to the streamer with the correct hardware would be the best way to go since you are trying to get the best sound quality. Having the galvanic isolation between the server and streamer will get rid of any upstream noise (in theory) that travels through the ethernet cables (if there even is any to begin with). The wireworld ethernet cables are really good ethernet cables already so I doubt there is much noise to begin with, and other people will argue there is no noise due to how ethernet works in the first place. My thinking is that if you put a short run in where you have suggested is that you could puck up noise from either of the two switches that come after it either from the switch itself and everything else that are connected to those switches. The way you have suggested only galvanically isolates the Verizon Fios router from everything else. Putting a short run of Fiber between the last switch and your Antipodes server would galvanically isolate the server and your streamer from the rest of the system. No matter what you do though, using a generic FMC with a generic wall wart could introduce its own noise, which is why I suggested the Sonore products with LPS.

Thanks for the suggestions. You have answered one of the questions I had, which is whether a short run of FO is beneficial. I am considering the OM in that regard.

Thanks, good to know.

How about the Gigafoil?

My understanding of the Gigafoil is that it is most effective when placed toward the end of the chain, not the beginning.

Maybe so but I use three of them. I have one to each of DACs at the end of the chain as you describe and then I have one immediately off the router into the switch as the ethernet runs are long to each of my two systems upstairs and downstairs and the router cannot be moved closer.

And an optical rendu off the server too!

To get the best sound you need to keep noise out of your DAC. So the best place to put the network isolation is just before the Cary DMS-600 Streamer/DAC.

The opticalModule would be good for that. You put it just before the Cary DMS-600 Streamer/DAC and attach it with a 6 inch Ethernet cable (included with the opticalModule). The Ethernet cable is so short it picks up very little noise.

I imagine your router probably uses a 12V power supply. The iPower 12V version only puts out 1.8Amps, which may well not be enough. Check the requirements of the router before you choose a third party PSU, or you may run into problems.

[quote=“asindc, post:1, topic:115094”]
FMC —> 1m (or whatever length needed) FO Cable —> **Buffalo ■■-GS2008 switch

I believe that Buffalo switch only has regular Ethernet ports, not fibre, so you would need a second FMC to convert from fibre back to copper Ethernet on what is already a long, and it seems to me, unnecessarily complicated chain of network hardware. I think you would be better off choosing switches that have SFP ports as well as regular RJ45 ports, so that they can fulfil both functions. In fact, you already have one such switch, the EtherRegen, so if you convert to fibre before that, you can use it to convert back copper.

Remember that electrical interference can be picked up from the environment as well as more directly from a noisy PSU etc. For example, your in-wall Cat5 cable (which is probably unshielded) may be picking up interference from a nearby mains power cable. So I think you would be better off putting a fibre link near the end of the chain if you believe it will help to isolate your HiFi system from noise.

(On the subject of isolation, people often seem to be fixated on the term ‘galvanic isolation’ as if it’s some sort of cure-all. If it was, there would be no need to worry, as Ethernet itself includes galvanic isolation, so in your proposed network, you would have it in multiple locations. Its purpose is to eliminate ground loops, not to selectively filter out high frequency interference.)


Thanks for responding. I have already decided against the iPower because I can buy a TeraDak LPS for less money than similar LPSs.

Yes, I’m aware that the Buffalo BS-GS2008 does not have optical ports. Adding the Buffalo switch would be Plan C at this point. Actually, I am close to deciding to drop the Buffalo switch idea altogether.

I am going to get quotes on having fiber optic cable run from my router position to my music room, a run of about 20-25 feet. If it is feasible and I find FO to be beneficial, that is the preferred option. If not feasible, I might try a second EtherREGEN or another switch between the router and the long CAT5e run to the music room.

Your point about galvanic isolation vs. eliminating ground loops is interesting. Do you have a source for further reading?


This is what my Plan A looks like. The idea is to test whether replacing the long run of CAT5e to the music room with FO is practical and beneficial enough to make these changes.