The EtherREGEN thread for various network, cable, power experiences and experiments

[R1200CL]

11 hours ago, Superdad said:

A great many aspects of the EtherREGEN's architecture would have to change to support Gigabit on the 'B' side.

So even a simple (dual?) DC powered with only one SFP(+) in and equal one out with external clock interface would still be expensive? Like more than $999 ?

[kennyb123]

16 hours ago, James Stephens said:

All this talk of SFP vs SFP+ modules has got me wondering about potential sound quality differences between modules and also single mode vs multimode and whether it might make a difference SQ-wise.

 

What do people think?

Listeners have tended to prefer single mode over multi mode.  1000BASE-LX seems also been preferred, possibly due it’s longer wavelength - but also due to the fact that listeners aren’t finding the need to use attenuators with SFPs that meet this standard.  There was a working hypothesis that the lower the power draw of the SFP the better the sound quality.  That may have lead to attention given the Finisar 1324, which is my current favorite.  

[James Stephens]

17 hours ago, kennyb123 said:

Listeners have tended to prefer single mode over multi mode.  1000BASE-LX seems also been preferred, possibly due it’s longer wavelength - but also due to the fact that listeners aren’t finding the need to use attenuators with SFPs that meet this standard.  There was a working hypothesis that the lower the power draw of the SFP the better the sound quality.  That may have lead to attention given the Finisar 1324, which is my current favorite.  

Thanks. The albeit limited number of opinions out there on this does seem to point in favor of single mode. It "feels" to me like the better choice given that a more precise laser beam is directed down a much narrower core in the case of single mode vs led light bouncing around as it makes its way down a much larger core in the case of multimode.

[MarkusBarkus]

...the light is "bouncing around" in the single mode cable too, it just has different "bounce" characteristics.
 

Sure, the SM lasers are more powerful/coherent, the cable core narrower/more constraining, but these cables are snaked around through walls, etc. and not in a straight line. 
 

It's not clear to me why folks seem to prefer SM over MM for audio. But, just because I didn't hear a reliable difference, doesn't mean others don't/won't. I'm on SM fiber, it should be noted.
 

I ordered a couple of SFP+ transceivers to test, which is at the heart of the latest dust-up regarding optical stuff. Will it make an audible difference? Will it even work? I'll find out! 

[James Stephens]

36 minutes ago, MarkusBarkus said:

...the light is "bouncing around" in the single mode cable too, it just has different "bounce" characteristics.

 

 

Yes, of course.

 

38 minutes ago, MarkusBarkus said:

I ordered a couple of SFP+ transceivers to test, which is at the heart of the latest dust-up regarding optical stuff. Will it make an audible difference? Will it even work? I'll find out! 

 

Interested to hear back on this ... 

 

Best,

James

 

[charlesphoto]

@MarkusBarkus It will be interesting to hear what you think. IMO I think we’re right on the edge of what I’ll call the ‘unicorn forest’ with these SFP choices. I think I’m good with my Finisar 1324’s into my oM and oR. I wasn’t sure how much change I heard going from multi to single mode - the quality of transceiver device and how and where it’s powered make significantly more change then the SFP choice imo. 

[R1200CL]

My reason to prefer and recommend DFB laser and sigel mode fiber 1310 nm is based on research done by people participating in the White Rabbit Project. The interest was at that time phase noise. You will have to do a lot of google and scan to various documents to find this. Phase noise is easier to find info about. They even developed their own switch. 
 

It also seems that manufacturers almost only use DFB laser and single mode support in 10GB and also SFP28. Yes a SFP28 module will fit the EtherRegen. 

 

I also studied several data sheets (including old ones) from Finisar that until some time last year was available at Finisar website  together with a very nice overview about the various all type optical modules. To bad this was removed. Maybe cause I emailed them with questions about the various modules ? 

 

At that time jitter numbers was available. (Still is on the 1421). 

This is why I recommend FTLF1421P1BCL and of cause the lately discovered use of FTLX1475D3BTL. 
I have obtained 10 of the SFP version. I will also test one or two off the SFP+ version. 
 

I have asked JohnS if he can se any technical benefit with one vs the other, since both is 1310nm with DFB laser.

Based on the strict requirements of the 10GB standard, one could assume better quality of SFP+ modules. 

However this also requires the equipment used with the 10SFP+ module to comply with that standard. Not that is should matter that much for our purpose. I don’t know. 

Both modules cost the same new, but the 1421 is widely available on eBay at a reasonable price.

I would assume it’s enough with one FTLX1475D3BTL to obtain any possible benefit of the 10GB SFP+ and it may be beneficial to use the 1421 in the other end, as you then can use a 10GB switch, which you can’t if both modules is 10GB FTLX1475D3BTL

 

https://ohwr.org/project/white-rabbit/wikis/Non-compliantSFP

https://ohwr.org/project/white-rabbit/wikis/SFP

 

[GryphonGuy]

11 hours ago, MarkusBarkus said:

...the light is "bouncing around" in the single mode cable too, it just has different "bounce" characteristics.
 

Sure, the SM lasers are more powerful/coherent, the cable core narrower/more constraining, but these cables are snaked around through walls, etc. and not in a straight line. 
 

It's not clear to me why folks seem to prefer SM over MM for audio. But, just because I didn't hear a reliable difference, doesn't mean others don't/won't. I'm on SM fiber, it should be noted.
 

I ordered a couple of SFP+ transceivers to test, which is at the heart of the latest dust-up regarding optical stuff. Will it make an audible difference? Will it even work? I'll find out! 

 

My own experimentation in my network found that 1310nm signals were far better than the 850nm wavelength. I do not know whether 850nm is an LED emitter and the 1310nm a proper laser, I just know that over OM5 cabling (I tried OM4 with subtle differences not worth the expense either way) the 1310nm audio sounded much better with deeper blacks more impactful transients etc etc. Everything an audiophile tries to achieve.

 

I have not tried single-mode fibre.

 

Regards

GG

[GryphonGuy]

4 hours ago, R1200CL said:

My reason to prefer and recommend DFB laser and sigel mode fiber 1310 nm is based on research done by people participating in the White Rabbit Project. The interest was at that time phase noise. You will have to do a lot of google and scan to various documents to find this. Phase noise is easier to find info about. They even developed their own switch. 
 

It also seems that manufacturers almost only use DFB laser and single mode support in 10GB and also SFP28. Yes a SFP28 module will fit the EtherRegen. 

 

I also studied several data sheets (including old ones) from Finisar that until some time last year was available at Finisar website  together with a very nice overview about the various all type optical modules. To bad this was removed. Maybe cause I emailed them with questions about the various modules ? 

 

At that time jitter numbers was available. (Still is on the 1421). 

This is why I recommend FTLF1421P1BCL and of cause the lately discovered use of FTLX1475D3BTL. 
I have obtained 10 of the SFP version. I will also test one or two off the SFP+ version. 
 

I have asked JohnS if he can se any technical benefit with one vs the other, since both is 1310nm with DFB laser.

Based on the strict requirements of the 10GB standard, one could assume better quality of SFP+ modules. 

However this also requires the equipment used with the 10SFP+ module to comply with that standard. Not that is should matter that much for our purpose. I don’t know. 

Both modules cost the same new, but the 1421 is widely available on eBay at a reasonable price.

I would assume it’s enough with one FTLX1475D3BTL to obtain any possible benefit of the 10GB SFP+ and it may be beneficial to use the 1421 in the other end, as you then can use a 10GB switch, which you can’t if both modules is 10GB FTLX1475D3BTL

 

https://ohwr.org/project/white-rabbit/wikis/Non-compliantSFP

https://ohwr.org/project/white-rabbit/wikis/SFP

 

 

Your theory needs practical testing. There's something for you to do! 😉

 

With fibre, the golden rule is not to mix and match different model transceivers on the ends of the fibre, as has been stated ad nauseum lately. So when you see something that fits the bill, so to speak, you buy two or in pairs.

 

Regards

GG

[GryphonGuy]

oh,

 

I'll just add, don't buy the 10km type transceivers for a meter or 5 run of fibre. The laser will be too bright for the other end. You would need to buy an attenuator for each transceiver as well if you insist on buying the tens of kilometre range transceivers.

 

I stick with the 1310nm 2km range. No problems yet but I need to run 30 metres of fibre so the losses in that run of round corners etc might be enough to dull the transmission to acceptable levels.

 

I'd be happy to be proven wrong here, as I don't know that technical side.

 

Regards

GG

[R1200CL]

1 hour ago, GryphonGuy said:

I have not tried single-mode fibre.

Actually 1310 is single mode. 1300 can be MM. Name those SFP you’re using.

Anyway that SQ confirmation of 1310nm is nice. 

 

1 hour ago, GryphonGuy said:

Your theory needs practical testing. There's something for you to do! 😉

 

With fibre, the golden rule is not to mix and match different model transceivers on the ends of the fibre, as has been stated ad nauseum lately. So when you see something that fits the bill, so to speak, you buy two or in pairs.

I will. Still nothing wrong in mixing those two specific modules I think. I’m quite sure equal laser wave length and same manufacturer ensures that. Still I totally agree. Testing is good. And just found the 10GB below $40. 

We could even ask @AfterDark. to test some combination of the modules he has, but maybe he won’t. Won’t benefit his sale I guess. 
 

1 hour ago, GryphonGuy said:

I'll just add, don't buy the 10km type transceivers for a meter or 5 run of fibre.

 

This a totally disagree with. Now you’re the one creating confusion about something well tested.

This the same saying don’t purchase Adrian’s nice 10GB modules. 

I’m using this 1421 with a one meter cable. No problem at all. 
And if it really is an issue for someone, just add $10 and purchase 20 meter and hide it behind your rack.

 

I like to hear the arguments about too bright.
 

[MarkusBarkus]

11 hours ago, R1200CL said:

I like to hear the arguments about too bright.

I would too. I will try to find some actual technical info on it. I suspect phone calls may be required. We have a lot of photonics research here in upstate NY.

I recall posting previously that statements about "over-bright" lasers and SFP "burnout" seemed to me to be anecdotal in nature. "Swamping" or "over-saturating" the transceivers.

Also, coiling a bit of extra cable wouldn't do much to attenuate a laser signal moving at the speed of light, also IMO.

 

I suspect that if the receivers are designed/built to accept a certain wavelength and type of laser, they would not be overwhelmed by closer proximity. I am not an expert on lasers, BTW. 
 

All of the info I see is more about retaining signal integrity/intensity over distance and in bending applications by improving the sheathing/cladding materials, creating "moats" or "trenches" to redirect light back toward the core. No one seems worried about too much signal, albeit with the previous caveats of matching wavelengths, types, etc. 

 

I think it is more likely the case that because SM components cost a bit more, and are desired/required to allow signal integrity across longer distances, practical engineering would not recommend them for short runs, since MM is designed and works well for that purpose. 
 

As usual, as a community, audio enthusiasts are off-piste and testing off-label usages in the jungles of Audioland . Bravo audio experimenters! 

[James Stephens]

2 hours ago, MarkusBarkus said:

I suspect that if the receivers are designed/built to accept a certain wavelength and type of laser, they would not be overwhelmed by closer proximity. I am not an expert on lasers, BTW. 
 

All of the info I see is more about retaining signal integrity/intensity over distance and in bending applications by improving the sheathing/cladding materials, creating "moats" or "trenches" to redirect light back toward the core. No one seems worried about too much signal, albeit with the previous caveats of matching wavelengths, types, etc. 

 

 

Here's an interesting data point:

 

I am currently using StarTech SFP1000ZXST 1000BASE-ZX SFP modules over OS2 fiber between my OM and ER. These are 1550nm, single mode, 70km, modules. I'm not using any attenuators.

 

They aren't cheap; a more exacting laser is required for the longer distances as I understand it.

 

See https://www.startech.com/en-us/networking-io/sfp1000zxst for specs. Unfortunately, the specs are nowhere near as detailed as for the Finisar SFP's ...

 

The Taiko Audio contingent tested a bunch of SFP's and rated the StarTech ones that they tested the best. Google "taiko startech sfp1000zxst"; the info is on the whatsbestforum.

 

I haven't done detailed tests myself but they do sound very nice to me.

 

Best,

James

 

[PYP]

2 hours ago, James Stephens said:

I am currently using StarTech SFP1000ZXST 1000BASE-ZX SFP modules over OS2 fiber between my OM and ER. These are 1550nm, single mode, 70km, modules. I'm not using any attenuators.

That is interesting.  What is the length of the OS fiber cable you are using?

 

SFP modules seem robust except for the connectors, which look fragile.  Have you had any issues yanking the old ones out?  

[kennyb123]

2 hours ago, James Stephens said:

 

Here's an interesting data point:

 

I am currently using StarTech SFP1000ZXST 1000BASE-ZX SFP modules over OS2 fiber between my OM and ER. These are 1550nm, single mode, 70km, modules. I'm not using any attenuators.

 

They aren't cheap; a more exacting laser is required for the longer distances as I understand it.

 

See https://www.startech.com/en-us/networking-io/sfp1000zxst for specs. Unfortunately, the specs are nowhere near as detailed as for the Finisar SFP's ...

 

The Taiko Audio contingent tested a bunch of SFP's and rated the StarTech ones that they tested the best. Google "taiko startech sfp1000zxst"; the info is on the whatsbestforum.

 

I haven't done detailed tests myself but they do sound very nice to me.

 

 

I jumped on those but found that I could hear the harm over saturation was doing.  I was not alone.  An attenuator was a must with these just to get that hard edge dealt with.  I ultimately dumped these and am now using the Finisar 1324 also recommended by Taiko.  Much better and no need for attenuators.
 

 

 

[James Stephens]

18 minutes ago, PYP said:

That is interesting.  What is the length of the OS fiber cable you are using?

 

Hi there, 5m length. From OM in basement up to Living Room and out through a brush plate to the ER.

 

18 minutes ago, PYP said:

SFP modules seem robust except for the connectors, which look fragile.  Have you had any issues yanking the old ones out?  

 

I am always super careful when squeezing the duplex clip so that I don't crush the heat shrink tubing behind it for example ... I haven't damaged one yet lol. 

 

[James Stephens]

1 minute ago, kennyb123 said:

 

I jumped on those but found that I could hear the harm over saturation was doing.  I was not alone.  An attenuator was a must with these just to get that hard edge dealt with.  I ultimately dumped these and am now using the Finisar 1324 also recommended by Taiko.  Much better and no need for attenuators.

 

 

Hi. Thanks. I do plan to try some Finisars .. it is fun experimenting ... which specific part number?

 

Best,

James

 

[James Stephens]

2 hours ago, James Stephens said:

See https://www.startech.com/en-us/networking-io/sfp1000zxst for specs. Unfortunately, the specs are nowhere near as detailed as for the Finisar SFP's ...

 

Apologies .. I had a . at the end of the URL before so it wouldn't work. Here is the correct URL:

 

https://www.startech.com/en-us/networking-io/sfp1000zxst

 

 

[kennyb123]

1 hour ago, James Stephens said:

 

Hi. Thanks. I do plan to try some Finisars .. it is fun experimenting ... which specific part number?

 

Best,

James

 

FTLF1324P2BTL

[MarkusBarkus]

4 hours ago, James Stephens said:

The Taiko Audio contingent tested a bunch of SFP's

Ha! That is a moving target. I have the "Planets" in mine--also recommended. Variously, Finisars and Startechs have been in and out of favor. 
 

Actually, I think @kennyb123has "rolled" several SFPs to compare and has good feedback.
 

I would like, and plan to try, the Finisar SFP+ in the Taiko. I ping-ed Emile Bok to see if he has any cautions there--other than, X sounds better. I have only fed it via SM optical, SFPs. 

[kennyb123]

2 hours ago, MarkusBarkus said:

Actually, I think @kennyb123has "rolled" several SFPs to compare and has good feedback.

Yeah I definitely have a problem.
 

 

[austinpop]

Ken, clearly you're a starter, but not a Finisar!

[James Stephens]

Lol I have a few months on the Planet Technology MGB-TLX's pictured by @kennyb123and also mentioned by @MarkusBarkus.

 

Here is the link for others that may be interested in those: https://planetechusa.com/product/mgb-tlx-mini-gbic-lx-module-20km/

 

I mentioned the StarTech SFP1000ZXST's because the subject of overloading the receiver was being mentioned ..  and we hadn't discussed 1550nm or even 1000BASE-ZX SFP's at all ... I wouldn't have tried them unless Taiko had mentioned that they had been in production "for 9-10 months"

 

Cisco does recommend 10dB attenuators for their 100-BASE-ZX SFP's in cases where there is less than 8dB of attenuation to avoid overloading the receiver ...  

 

I see that the Finisar FTLF1324P2BTL's are no longer in production (for 3 years now). I wasn't able to find any on Ebay ......

 

Best,

James

 

 

[R1200CL]

15 minutes ago, James Stephens said:

I see that the Finisar FTLF1324P2BTL's are no longer in production (for 3 years now). I wasn't able to find any on Ebay ......

The data sheet is from 2006. It’s a vey old module. It’s rated up to 4 km. It uses 1310 nm FP laser.

 

Attached is a good option. You can get them as low as $10. 
 

Another thing. The word attenuator doesn’t exist on Finisar site. 😀
 

finisar_ftlf1421p1xcl_oc-48_ir-1_stm_s-16.1_rohs_compliant_pluggable_sfp_transceiver_product_specification_0.pdf

[MasterWarzombie]

Delivery tomorrow of my first Farad to supply the etherregen. So I chose 9 volts which will allow me to test on my other Sotm products which are all 9 volts.
I chose with a direct orange SR fuse! and the reference cable from the Farad retailer in France.
I also ordered the DC Level copper cable from FARAD.

To be continued