2. tech-talk
  3. 195158-133364

Using optical Ethernet input for your Hifi Rose RS130

This conversation is very specific for RS130 owners. Nowhere on the Internet (and I never got a response from Rose customer support) does it tell you what components to purchase to use an optical instead of a copper Ethernet input to the RS130. The subject gets into data center technology, which I had no knowledge of. So, after lots of trial and error and purchasing the wrong components, I present this as a guide to help others find an easier path for using an optical input for their RS130.

 

After several weeks of trial and error, here's what I discovered. Experts, please correct me. For those of you who want to use an optical INPUT to the Rose RS130, here's the TL;DR. You need a:
1. **Single-mode base1000-x copper to optical fiber transceiver,** The "-X" stands for anything with an "X" in it, like base1000-LX. e.g., 
10GTek Fiber to Ethernet Media Converter, Gigabit Single Mode SFP LC Converter, 1000Base-LX to 10/100/1000M RJ45, SMF, 1310nm, up to 20km (12.4miles)(https://www.amazon.com/dp/B07B9XFC9L?ref=ppx_yo2ov_dt_b_fed_asin_title)
2. **Single-mode LC to LC fiber optic cable** (1 or 2 meters). e.g., [FLYPROFiber- 1M/3ft OS2 Single Mode LC to LC Fiber Patch Cable, SM Singlemode Duplex, SMF Fiber Optic Cable Cord, 1G/10GB, 9/125um, LSZH](https://www.amazon.com/dp/B08B3JT2V3?ref=ppx_yo2ov_dt_b_fed_asin_title)
3. Two **SFP (not SFP+) LC modules** that work with your transceiver--make sure it says something like, "compatible with TP-link," if that's the maker of your transceiver.   e.g., H!Fiber 1.25G Single Mode SFP LC Module, 1000Base-LX/LH Fiber Transceiver. NOTE: the transceiver listed above comes with an SFP module, so you only need to purchase an additional SFP to put into the RS130.

I hope this helps. (I never got a response from ROSE customer support.) 

Misc basics:
1. To insert or remove an SFP module, pull down on the bar at the back (outside) of the module. If you're inserting it into the RS130, insert it--push it kind of hard until it clicks, raise the pulldown bar to its original (up) position, and insert the cable--make sure it clicks into the SFP. To remove the module, remove the cable by pushing down on the button on the fiber cable that locks it into the SFP, pulling down the bar, and pulling the SFP from the RS130.
2. There are single-mode and multi-mode fiber cables, transceivers, and SFPs. They must all be one or the other. Single-mode is supposed to sound a bit better than multimode. I listened to both. There is a SLIGHT improvement for single mode, but it's not dramatic. In part, this depends on how revealing your stereo system is. The price for the two is about the same so, just go with single mode.
3. About fiber cables, and this will show you how much of a neophyte I was, they come with 4 small white plugs at both ends of the cable. Remove those before plugging them into the SFPs (unlike what I did, the first 5 times!).
4. Is it worth changing from copper to optical Ethernet input? YES! The cost is low—$50 for the whole set of optical components. Either your system sounds better than Ethernet over copper, or it doesn't. If not, return the optical parts to Amazon. In my system, the answer is definitely yes, the optical components improve the sound quality. I notice increased resolution and clarity. But that's just in my system; results will vary. Test yours carefully.
5. Use good copper Ethernet cables to go from your router to your transceiver. The Ethernet cable from Morrow (cheap) provides terrific results and has a 60-day return policy.
6. OS1 and OS2 are designations for single-mode fiber cables. OS2 is better than OS1. OM1, OM2, OM3, OM4, and OM5 designate multimode fiber cables. OM5 is the best; OM1 is the worst, and they're backward compatible.

That's it! Mystery solved! Enjoy your RS130 and let the music play on!

pennpencil

Showing 3 responses by pennpencil

pennpencil OP
126 posts
 

@erik_squires  Thanks for your thoughts! Yes, LC to LC is the way I went. I don’t know if I made it clear above that I (finally) got the optical input working. The router you mention is interesting in that it has an SFP port! It’s an SFP+, which, apparently, would hurt the RS130, which requires SFP. My copper Ethernet cable from Morrow comes from a mesh satellite. I guess you’re saying that if I had an option of a router or satellite with an SFP port, I’d get a better SQ. Interesting. One thing I learned is that my service provider (Spectrum) doesn’t permit more than one modem in the house (one works, a second won’t). If and when I upgrade my wifi network, I’ll look for a system that has an SFP port.

As for single-mode and multimode, there are significant differences that matter for data centers and transmission lines, but maybe not for audio. Single mode uses a higher bandwidth, a single core, and can transmit light for a 1000 miles - whatever. Multimode uses multiple fiber cores, a lower bandwidth, and is used for shorter runs---still miles in length. Both support the 1-2 meters we need between our router and streamer--although, I guess you could run a fiber cable all the way from your router (instead of coming from a mesh satellite) without degradation or electromagnetic interference. Anyway, how any of these differences influence the sound quality, I don’t know. I just go with my ears. I read that "some audiophiles find single mode provides a superior sound." It was very anecdotal. I ended up trying multimode first because I didn’t know what I was doing. ("Oh, OM4 must be better than OS2 because 4 is bigger than 2!" -nah...OM is multimode, OS is single mode.) I found MM did a great job creating a crisper SQ in my system, but finally got single-mode working. And frankly, there wasn’t much of a change. Perhaps I heard something a little better, but that might have been wishful thinking—it takes minutes to switch out the SM for MM components, and the longer the delay, the more the imagination plays. 

Bottom line, the rig is working with the parts I listed above — listed in case someone doesn’t want to go through trial and error. MM or SM might sound different in your system. Perhaps a router with an SFP port would improve the SQ. And, in my system, optical input is noticeably superior to copper Ethernet input - although I know that’s not the case for everyone. 

I’m sure all this is TMI for just about everyone but the two of us! LOL.

Thanks for your suggestions!

pennpencil OP
126 posts
 

:-)   With all the stuff in my system, I’m not sure what "expensive" means anymore!

SFP supports up to 1 gig bps, SFP+ supports up to 10 gig bps. Both are plenty fast. I’d use the plus, but I read (somewhere) that SFP+ can hurt the RS130 because it runs a 1 gig, not faster. Otherwise, I’d prefer the faster speed (although in all practicality, it might not make a big difference). But coming straight from a router instead of going through a transceiver suggests there might be an improvement in SQ. and yes, I see there are routers with SFP ports! thanks!

pennpencil OP
126 posts
 

Definitely, the optical isolates the system from EMF that runs through copper. My previous streamer was an IFI Neo Stream that comes with an optical Ethernet input. I A/B'd copper and optical, and there was a noticeable difference in my system--crisper, more detailed. But that's just my system. That's why I took the pains to figure out the optical components for the RS130. 

More to discover