SFP/FMC/Optical cable - The only important ethernet cable?

[TRHH]

There is simply no mechanism by which noise can be transferred over an optical cable.

Noise is transferred over electrical connections and no such connection exists using optical. Fiber will kill any noise being transmitted with the data which contains the digitised music.

If this this the case, than the only important ethernet cable would be from FMC to DAC/Streamer - the rest can be "simple" CAT6 U/UTP (see below illustration).

What are you thoughts about that?

Torben

 

[MarcelNL]

That sounds a bit simplistic IMO, noise effects contained within the bits/bytes will pass through a fiber optic cable, and fiber optic cables contain a conversion step from optical to electrical signal.

 

Every aparatus using UTP/STP cable is capable of polluting the digital signal on it's own, so everything matters (as much as i'd wish that not to be true)....to the point where it's possible to hear the difference between various LPSU's powering a router upstream from a dedicated audio fiber optical stretch in my network.

[Iving]

16 minutes ago, MarcelNL said:

That sounds a bit simplistic IMO, noise effects contained within the bits/bytes will pass through a fiber optic cable, and fiber optic cables contain a conversion step from optical to electrical signal.

 

Every aparatus using UTP/STP cable is capable of polluting the digital signal on it's own, so everything matters (as much as i'd wish that not to be true)....to the point where it's possible to hear the difference between various LPSU's powering a router upstream from a dedicated audio fiber optical stretch in my network.

 

Agreed

 

My offline local-playback-only Dante system music player PC is upstream of RedNet DDC/Reclocker/DAC, separated by optical. Parameters of PC domain affect SQ - inc. power supply.

[audiobomber]

I agree with @Iving and @MarcelNL. Changes upstream from the fiber conversion, e.g. ethernet cables, power supplies and switches, affect sound quality through the DAC.

 

I just ran through a bunch of ethernet cable changes between my NAS and switch, and from the switch to the FMC. Every cable change was easily audible and critically important to the sound coming from my speakers. Have you tried any different cables upstream to test your theory?

 

Q. What about fiber-optic interfaces? Don’t these block everything?

 

A. In the case of a pure optical input (zero metal connection), this does block leakage current, but it does not block phase-noise affects. The optical connection is like any other isolator: jitter on the input is transmitted down the fiber and shows up at the receiver. If the receiver reclocks the data with a local clock, you still have the effects of the ground plane-noise from the data causing threshold changes on the reclocking circuit, thus overlaying on top of the local clock.

https://cdn.shopify.com/s/files/1/0660/6121/files/UpTone-J.Swenson_EtherREGEN_white_paper.pdf?v=1583429386

[TRHH]

16 hours ago, audiobomber said:

I just ran through a bunch of ethernet cable changes between my NAS and switch, and from the switch to the FMC. Every cable change was easily audible and critically important to the sound coming from my speakers. Have you tried any different cables upstream to test your theory?

 

 

There have been no improvement in SQ with different ethernet cables from ROCK to switch. From switch to FMC, no, I use fiber from switch to FMC, no ethernet.

 

There have been a small improvement when implementing OS2 Single Mode Grade B Fiber Patch Cable.

 

 

 

And from FMC to DAC/Steamer:

 

 

 

Torben

[kennyb123]

On 7/12/2023 at 12:57 AM, TRHH said:

There is simply no mechanism by which noise can be transferred over an optical cable.

Not my experience at all.  If we consider noise to be defined as “an electric disturbance in a communications system that interferes with transmission or reception”, any of us who have heard differences from changing components upstream of our fiber span know this to be false.  There are disturbances that can either pass down a fiber span or can harm wha’s being passed that can do harm to the music.  
 

Perfection simply doesn’t exist in the real world - especially not in systems designed by humans.   

[kennyb123]

16 hours ago, TRHH said:

There have been no improvement in SQ with different ethernet cables from ROCK to switch. From switch to FMC, no, I use fiber from switch to FMC, no ethernet.

Then a choice you have made is keeping the noise floor at a level that is preventing you from hearing differences.

 

There’a a TRHH who posted on WBF - is that you?  Then your Startech FMC could be a culprit in that.  

[SQFIRST]

Congrats on getting a noise free system as that is truly not easy. The moment you think it is solved the gremlins will come along with a new noise issue. Based on your layout diagram what I can guess is that somehow you have found a balance with power supplies, components and an exceptional set of Convolution room correction filters that are effectively giving a stable sound system. Power and network isolation is a totality consisting of multiple targeted implementations, of which fiber is one. Difficult to pick out which one is the most important as it is really a System. Wish it was one thing though as that will make things so much easier...

Enjoy the music!

[TRHH]

@SQFIRST Here diagram showing the power part of the setup:

 

[SQFIRST]

Nice setup TRHH. From this thread it does appear that you are focused on common mode noise and that does get blocked with optical. Sorry if off topic, but just curios, what do the ferrite cores do for you? 

[TRHH]

11 minutes ago, SQFIRST said:

ferrite cores

 

Ferrite cores are used to suppress electromagnetic emissions by blocking low-frequency noise and absorbing high-frequency noise. This avoids electromagnetic interference.

 

Makre sure to use Würth Elektronik - they are the best. Don't cost much - 5-6 EURO for 12.5 mm.

 

Torben

 

 

[SQFIRST]

If you are able to share I was curios about any listening impressions you may have been able to discern from using them.

[TRHH]

@SQFIRST - A bit more solid bass and more clear soundstage. Small, but nice improvements.

 

It has been part of targeting different potential noise sources. 

 

Torben

 

PS: Same goes for: