Optical vs Ultra Rendu.

Is it worth the $696 more to go with the optical Rendu:


Over the standard (ethernet connected) ultra Rendu:


Has anybody compared these units, is there a notable difference in sound quality between these two?  Both still connect to the DAC via USB. 


I had the ultraRendu for a few months before moving up to the opticalRendu. At least in my system, it was a noticeable improvement ... the main benefit is noise floor reduction. With the opticalRendu, I can hear more details emerging from a blacker background. During the same time period, I auditioned Innuos Zen Mini, Lumin D2, and Lumin U1 Mini. I found the opticalRendu to be better than the aforementioned streamers.

arafiq - great feedback, thanks.
By chance, did you happen to compare the Optical to the Ultra?

The difference between the two is in the name: opticalRendu has a fiber optic SFP port while the ultraRendu has an RJ45 ethernet port. Copper ethernet and fiber optic both offer galvanic isolation, making them an ideal connection between digital components. Fiber optic is also immune to EMI & RFI–a characteristic not found over ethernet. This is why many report a lower floor noise after implementing fiber optic.

Unless your server has an SFP port, you will need to use a fiber media converter to convert ethernet to fiber optic and then into the opticalRendu. This adds another device, another power supply, another cable.

@sns recently switched from a SOtM sMS-200 to the opticaRendu. Perhaps he can share his impressions.

Sonic79 - Thank you for the Explanation. Have you personally heard the difference between these two units?

I can only compare directly to SOTM SMS200 Neo with two FMC, all powered by lps. OpticalRendu not an insignificant upgrade to that setup, really plays in different league, significantly lower noise floor and far more relaxed presentation. I presume lps used with OpticalRendu important, I use Uptone JS-2.


Sorry, can't help with UltraRendu, but based on a number of impressions from various reviewers OpticalRendu and/or Signature version both improve on some much more expensive streamers. OpticalRendu is really special IMO.

@high-amp No I have not compared them. I've only read about the opticalRendu anecdotally. It seems to garner very high praise, especially against streamers costing much more. I believe this is due to a combination of the fiber optic input and a low noise USB output. I don't have a need for one in my system presently. I am in the process of building a music server that will have a fiber NIC, so in the future I may get one to replace the Raspberry Pi I currently use. Sorry I can't help compare it to the ultraRendu.

What I don’t understand is do I need 2 optical Rendu ?

my setup from modem to router ,then long run of WWorld starlight cable 

to uptone Etherregen to AQ Diamond Ethernet cable ,to dedicated Audio computer to Final Touch Audio Callisto usb cable . What’s needed to make the optical rendu work in my system ?

@audioman58 -- I have the opticalRendu in my second (home office system). SmallGreenComputers sell a bundle that includes a separate power supply and an FMC bundle -- the cost of the bundle adds an extra $200 I think. My system is setup like this ...

Router >> Switch (which is optional) >> ethernet cable >> media converter >> fiber optics cable >> opticalRendu >> USB >> DAC

The only additional step compared to other streamers is that you insert a fiber-to-ethernet converter in between the streamer and your ethernet connection. It sounds more complicated than it really is. The other option is to buy a network switch that supports fiber optics output.

Ok Thank you , I take it I need 2 Ethernet cables or 3  from modem to router at least one Ethernet cable then rendu optical to a rj45 Ethernet converter ,then run fiber optic to another optical rendu then Ethernet cable to computer, from computer 

usb cable to dac , plus linear power supplies ,the optical Rendu I thought like 

$1200  each , is this correct ? Total outlay $$ wise around $4 k ,

unless there is a much easier less expensive way .

thanks much Everyone forthe options and assistance ,please letme know the$$ cost ,

@audioman58 -- you don't need two opticalRendus. You can get the opticalRendu bundle (which gives you everything you need to set it up) for under $1700. I'm not sure why you think you need two opticalRendus. I have only one in my system and it is a really good streamer for the price.



Your setup would be modem>(via ethernet cable)router>FMC>(via optical cable)OpticalRendu>USB in on dac. OpticalRendu $1500 plus FMC $25 or so, $6 optical cable, plus lps for opticalrendu and FMC (optional lps). Get good power supply for OpticalRendu, best you can afford.

At some point you may want to look into getting a switch rather than going out from relatively noisy router.

imho the upgrade to the optical rendu is definitely worth it, it is a noticeable improvement in my system, to my ears

+1 @arafiq 

It looks like the bundle is called the FMC bundle on their website. The price changes automatically when you choose it. I got a $49 extra when I clicked it. You can also choose to get a better power supply, an LPS, which also adds a bit extra to the total price. You do need the FMC bundle unless you already have an optical converter.

I too asked the same question when I was purchasing their products. The optical Rendu seemed to be the same as the ultra Rendu with a built in media converter for the +$700 bump in price. I went with the uR and decided to use two media converters to make the optical filter :

router > ethernet cat 8 > $15 switch > cat 8 > i5 Transporter.

Same switch > cat 8 > FMC > Fiber optic > FMC > cat 8 > uR > USB cable to DAC.

I had completely solved all power problems in my system to achieve a superior black background. The above still had grunge :

1. I added a LPS with a Y adapter to power both FMC = better

2. I added a LPS to the Transporter = better

3. I replaced the LPS power chords with Pangea Audio AC-14SE MkII = better

4. I wrapped my fiber optical cable in bubble wrap. It seems they are sensitive to vibrations. = better

5. I replaced the 3 post switch cat 8  ethernet cables with Pangea Premier SE = way way way better, but STILL some remaining niggly grunge!

I had not bought into the $700-$2000 ethernet switch nonsense. I had bought my $15 plastic covered  switch from Home Depot. I did try a more expensive switch and sent it back because I could hear no improvement. I rewired post switch and removed the FMCs. LISTENED. Then I added the FMCs back in. They were definitely improving the sound, by a lot!

6. I ordered a iFi iPower X Ultra Low Noise AC/DC Power Supply for the switch. I took out the FMCs again and installed the new PS. WHAM!! The sound came into complete focus. I reinstalled the FMCs again and now all the grunge had disappeared. The background is black and transparent to source. I now can hear exactly what Qobuz is offering. It is easy to parse all the different sound qualities offered to us.

So, no, I have not tried the oR, but I am satisfied that I am getting the best sound and saving about $500 in the process. Of course I have 9 boxes and associated cables, but I try not to think of that.

This was a 2 year journey. I learned a ton along the way. I hope it is helpful to someone else.



I too had less than successful experience with audiophile switch, YMMV. With my second ethernet out of server, switch is made superfluous, only adds detour with another added ethernet cable and switch. I use lps on my router, nice upgrade, router only feeds server, no return of signal back to router, simply goes from server to, in my case FMC. With ethernet and optical the shorter the path the better. Very few servers offer second ethernet out, with exception of Antipodes and Sonicorbiter I9, which is optical out. I simply don't understand this omission with most servers since it requires the above roundabout with either switch or router.


Most servers designed without separate streamer in mind which creates the need for switches for those who want to try separate streamers or streamer/dac, usb out of server not for everyone.

It’s funny that people are worried about sq when they use usb to their dac. If you want to increase sq, stop using usb.

If you have a noisy network, right before your dac when using the Ethernet input on your dac, get a pair of Ethernet to fiber converters with a good fiber cable between the converters. Pretty easy. Fiber can’t carry some of the garbage that is on a copper network.

It’s funny that people are worried about sq when they use usb to their dac. If you want to increase sq, stop using usb.

Definitely not a universal statement, such as the Musetec 005 DAC.


Here is a link about streaming from the guy (John Swenson) who built the Rendu's and EtherRegen. 

Raal Ribbon Headphones - SRH1A | Page 325 | Headphone Reviews and Discussion - Head-Fi.org


sns - "Get good power supply for OpticalRendu, best you can afford"

Do you feel the LPS sold with the Rendu (bundle) is inferior? And

"At some point you may want to look into getting a switch rather than going out from relatively noisy router."

Any recommendations on a good switch?

Also sns you state: "OpticalRendu $1500 plus FMC $25 or so"

In this bundle it does not show any FMCs, so what is this for?



singingg - super interesting journey, thank you for sharing. I'm hoping to get as close to what you have achieved, but somehow, without 9 boxes. You've definitely taken separates to another level!


rbstehno - "It’s funny that people are worried about sq when they use usb to their dac. If you want to increase sq, stop using usb."

Interesting comment, but both Ultra Rendu and Optical Rendu use a USB connection to the DAC.

I also had a Wyred 4 Sound 2v2SE DAC that the owner (E.J. Sarmento) recommended to connect both his MS music server and a Roon Nucleus to via USB for best sound quality.

How do you connect?


Then to add more confusion, the wiring diagram on the Small Green Computer site show a simple fiber ethernet cable going from the router to the optical Rendu.


So, what is all the extra hardware seen in this Hans Beekhuyzen video starting around 2:05. Such as the SFP media converters. What is the difference between these two set ups and will there be any difference in SQ? 


I have a BlueSound Node 2i.  Would this hook up to my BlueSound?  Has anyone done a true blind test?  This would require someone to change the connections to do an A/B comparison without the listener knowing the source by doing a random switching back and forth.  Try to stump the listener and then tell them which connection was what.  Some of these expensive add on little noticeable difference.  Kind of like splitting hairs in my opinion.  Which is more noticeable, upgrading speakers or amplifiers or using this add on?

the central idea of the optical rendu is to convert the audio signal into optical and then back to electrical just before sending it to the dac, such that any electrical noise on the ethernet fed electrical line is left behind

so of course, using any properly functioning fiber media converter to do the job will accomplish the objective

of course it is then key, on the receiving end of the signal that there be very quiet, noiseless power supplies used, so that new noise from such things as switch mode power supplies are then re-introduced into the music bearing signal

Thanks all. I have been researching a digital front end for some time now, sort of the last piece of the puzzle for me. It really seems this SGC bundle is something that checks all my boxes. My last hurdle was just trying to make the final call on the Ultra or the Optical. From what most of you are telling me here, it sounds like the $700 upgrade would be worth it. 

Another vote for Optical Rendu.  Here’s another product I just saw.  Interesting that it actually throttles down the speed to reduce noise and not too expensive.  Just another option...


One needs to think holistically when setting up streaming system. Network should be set up to take advantage of best input on dac. While some dismiss usb, usb is often best input on dac, many dac manufacturers have taken great pains to maximize usb format.

So, assuming usb superior input on dac, streamers such as optical and ultra rendu become viable and/or optimal streaming solution. The problem with usb in many streaming setups is using the common motherboard usb out on most servers, this is far from optimal. One must use one of the various usb renderers/improvers like Uptone usbRegen, Innuos Phoenix usb or any number of others to take advantage of full capability of dac usb input. OpticalRendu will eliminate any need for further usb rendering.


One must use FMC, optical out server or optical out switch in front of OpticalRendu, also must use LC format for optical module, this to make sure optical cable will be compatible with OpticalRendu. My present solution uses Bidi Gigabit Multi mode SFP LC FMC (purchased from Amazon) with 5v Teradak LPS, eventually will go to Sonore OpticalModule with LPS when chips become available for unit.


@high-amp I presume the LPS sold with Sonore bundle is fine, but assuming one gets full value with more expensive LPS, may not be optimum lps for OpticalRendu. As I mentioned previously, I use Uptone JS-2, aprox. $1k lps, I haven't tried another lps with my unit so can't ascertain for certain value of this lps in sound quality of my setup. I can only say major upgrade over SOtm, SMS200Neo which I also powered with the JS-2.


sns - thank you for your detailed response, but I'm starting to find this a little bit overwhelming. Would it be possible for you to send me a simple drawing via PM or attach it here, so I can get a better handle on what you have done with your system so I can possibly duplicate it?

The easiest way to get what you need if going with OpticalRendu, as mentioned above get the FMC bundle from smallgreencomputer. Your setup would be:

modem>router via ethernet cable> server via ethernet cable> optional switch via ethernet cable>FMC (included in bundle) via ethernet cable>OpticalRendu via optical cable included in bundle>dac via usb cable. If you get the bundle no need to worry about getting proper FMC, can be confusing as there are different type optical connectors. Don't worry about lps for everything but the OpticalRendu, the lps sold by smallgreen computer is fine, you could always try other lps at later date.

Great to see more people getting into optical. I recently tried optical after coming across Tom Gibbs’ article. There he invites the reader to try a $100 optical experiment to see how it affects their system. Because my streamer (iFi Zen Stream) doesn’t have optical-in, I converted the line from ethernet to optical and back immediately before the line enters the streamer. The difference with the optical line in place was very big, and I have a modest system. I went with a pair of media converters and transceivers from TPLink, and I went with a 1M optical cable from Monoprice. I big layer of grunge was removed from the sound.

I was recently chatting with an iFi rep, and the rep told me iFi was working on something optical. I think it’s just a matter of time before other streamer manufacturers figure out what Sonore’s already found.

@sns I didn’t realize that slowing down the signal to 100Mbps might be a good way to reduce noise further. That’s interesting. I’ve seen someone suggest that noise created by the extra energy required for SPF+ and single-mode are reasons that the lower standards of SPF and multi-mode might make them better for audio. Like you, I’m waiting for a company to put out a purpose built media converter for audio/video. I also want to see whether optical affects the HT picture.

There is an excellent office switch you can buy cheaply called the Cisco 2960. Despite huge production this business/office switch was still hundreds of dollars when new back in the day as it is built very well with an excellent internal power supply. Bought Used it is only a few tens of dollars these days. These switches have a great reputation in the audio world as the sound quality is comparable with the best audio switches. And it has an optical output which will connect directly to the OpticalRendu > via usb to dac.

Modem/Router > via Ethernet to Cisco 2960 switch > via optical to OpticalRendu

Also you would connect the Cisco 2960 via Ethernet to your Server.

Like all optical connections you need a little SFP module to be inserted into the OpticalRendu optical port and the Cisco optical port. I suspect that the Optical Rendu comes with one so you will just need to buy a compatible one for the Cisco. They only cost a few dollars.

@high-amp I may have assumed too much with my above scenario for your setup. While server is technically feeding the FMC, your ethernet connection to the FMC would come out of router, assuming you don't have switch.


A couple reasons why some use switches in addition to routers. One is they may have an excess of devices on network such that router doesn't have enough ports. Second is router is noisier environment than switch, therefore, switch is acting as filter, some may have better clocks and/or fiber out (Cisco switch mentioned above is one, UptoneEtherRegen another), and then adding the lps is adding to filtering effect. Also gets rid of complexity, getting rid of FMC and another ethernet cable.


Yes, the SFP modules need to be compatible, the OpticalRendu uses LC type connector, it does come with the unit. And yes, slowing down to 100Mbps and single mode are reportedly better, although the single mode not universally reviewed as superior. The purpose built FMC is the Sonore OpticalModule, presume this will result in further reductions in noise and provide better clocking vs. generic FMC's.


The reason I believe some find switches effective in their setup vs mine where I didn't is due to second ethernet port on my server. In my case router or noise is ONLY feeding my server, second port feeding first FMC completely filters network noise, the rerouting or detour required by adding switch only serves to complicate my network path, more direct path superior for me.I assumed cleaning network feeding prior to server would provide superior sound quality, in my case the added complexity  trumped the lower noise floor resulting in more info but cookie cutter images, totally unnatural, and this with audiophile switch with built in lps.  For those without second ethernet port on server, one is forced to use usb from server (usually noisy as it comes directly off motherboard) direct to dac or back to router or switch in order to add streamer, the router dirty, switch cleaner. For most comparing a second ethernet port out of server vs router or switch is impossible as their server's don't have the second ethernet port. I understand the point I'm making here is therefore moot to most, I keep reiterating the second ethernet port in threads because this was one of the most effective network optimizations I've experienced over the years I've been experimenting with network optimization. I would suggest for anyone looking to get a new server, and planning on running a separate streamer now or in the future they get one with second ethernet port! Another point here is that what's downstream of server is far more important than what's upstream, true in my experience and I've been told this from a number of personal conversations with the people at Uptone and Network Acoustics.



Thanks all. 

sns - I do not have a server, if I purchase a bundle from SGC the Sonictransporter i5 would be my music server.

My current router is a combo router/modem, an older Netgear AC1750 so the only reason I presume I would need a switch would be for a optical line for the Rendu. 

There hasn't been much emphasis on modems in most of these "Digital" conversations. My older Netgear AC1750 works great but should I consider upgrading it? It has been discontinued so this is the only this is the only link I could find for it:


@high-amp Don't put too much on your platter for the time being. Get the bundle and I5 and you'll be good to go, actually doing really well! You can upgrade router/switch later on, the bundle will supply vast majority of high quality streaming for you. I don't know which dac you're using, but this may be worth looking at down the road with these network upgrades, dac really most important component in the entire setup.

sns - thanks for all your help and advice. I will be using the DAC onboard my SPL Director Mk2 pre-amp to start. I have no idea how it will compare to the many other DACs touted here, such as Musetec, Denafrips, Holo Audio, MHDT, etc.

I tried starting a thread elsewhere to see if anybody has compare this on-board DAC to some of these DACs mentioned but no takers yet. The SPL line doesn’t seem to get a lot of press here on AG?

I may be maxed out for cash once I’m done and may have to leave out chasing DACs for my next life.

You can insert optical into your system much cheaper — about $80 — using this from Audiogon.  


soix - Thanks, but inserting what for $80?

This SGC i5 bundle includes a music server that has a Roon core built in saving me from purchasing a Roon Nucleus at $1,459. Then it comes with the optical Rendu, a LPS and all the cables for $2,695.

If you have a cost saving alternative, I’m all ears!!!

Honestly, in the past, I just ran a Roon Nucleus, via USB directly into my DAC and I thought it just sounded fine, but everyone seems to say USB to DAC isn’t so great. It’s also stated it's better to have a dedicated music server , then use  ethernet to DAC (better than USB) with optical being better yet.



I run the SMG/Sonore setup and just added optical units purchased from Amazon for $150.

Basically the TX/RX come in pairs, for about $60/pair. I used two pairs and have them between the switch and i5 and the switch and UltraRendu.

I can't say how it compares with the Optical Rendu because I've never used one. SGA was going the send out an OR for review, but so far that hasn't happened.

I ran the optical stuff to hopefully treat frequent crashes requiring resetting of the UR, i5 and Roon server. I don't have enough time on the clock to know if the crash problem has improved. I can say that installing the fiber system was a breeze, it's plug-and-play. It also keeps the UltraRendu well away from wifi, which was SMG's recommendation.

I like the SMG/Sonore stuff but it hasn't been trouble free. There's a review here

rooze - Interesting read, thanks. Could I trouble you for a link to the optical units you purchased from Amazon? Also, what are you using for a music server?

Do you have any idea what the alternative "one box solution" is, as mentioned at the end of the review?

FWIW, last fall I upgraded my digital chain from a VBA to Sonic transporter i5, UR, and SGC LPS.  I use the switch SGC recommended, a $22 Trendnet.  My system always seemed quiet, before and after upgrade.  I did not try OR.  My DAC lacked USB, which I was happy living without until the UR arrived, requiring a USB DAC.  Long story short, none of DACs I tried (4 DACs priced from $500 to $1300) sounded as good as my old  DAC.  The solution was the SGC USB to S/PDIF adapter.  Pricey at $500, but everything sounds pretty good now.  I will say that this digital chain is more revealing and less euphonic than the old set up, so I can now differentiate between really good recordings and not so good ones.  Honestly, I miss the euphony a bit.  I might try that iFi power supply for the switch.

Hello thanks for the info 

I spent $1500 on the New Reference  Excellent Final Touch Audio USB  cable for my dac, ,which is a Huge step up from the AQ Diamond ,WWorld platinum 8 , purist 30 anniversary and several others 2x as much ,their $900 Callisto-usb I still have and  has many great reviews ,I spend also  $800 on their Ethernet cable which is exceptional ,I never thought Digital cables can bring my system this close to Analog sounding without loosing detail.                                                                             these Sonore optical cables are $1200 each x2 is Thst correct?  plus you need a how many Ethernet cables 3 ?

from modem  to router, then from router to the Sonore Ethernet to fiber optic converter, then another Sonore on the other end ,since I am 10 meters away 

we are talking $2500 just for 2-Sonore Sonore Ethernet to fiber converters ,

plus at minimum IFIAudio wall warts for AC power, if linear then another $1k for 2 $$$ , 7nless I am missing something somewhere , Thanks for the assistance 👍


@high-amp Sorry...VBA is a generic term for any dedicated computer running Linux with Vortexbox server software. Before the Sonic Orbiter and Sonic Transporter products, Small Green Computer sold Vortexbox appliances, pretty cheaply, I might add. My first music server, in 2011, was a SGC VBA, for under a grand. My satisfaction with this server and with SGC were important factors in my decision to upgrade to the Sonic Transporter i5. The support from SGC is excellent.

Streaming was a mystery for me for years.  Called Andrew Gillis from SGC one day and got the full I5 bundle with optical rendu and I had the equipment in 2 days.  He set me up remotely and that 2nd night I was streaming Tidal Masters through Roon.  Never looked back.


i will pinch hit for @soix

fiber media converter set (a pair is needed) - this is similar to what andrew at sgc has bundled


then get a short run of optical cable:


then you should use a filtered 5v dc power supply for the receiving side of the optical pair (don’t re-introduce switch mode ps noise back in on the receiving end)


or better yet - this...