Poll and chat: Fibre Media Converters (FMCs)

FWIW I think that's the 10/100 version of the 2960. The 2960cg is the gigabit version and may be more desirable in your network. I wish I could get the time back I spent reading a thread about nervosa surrounding 10/100 vs gigabit for audio applications.

 

Good catch, mine are CGs.

 

Never looked into this (and not sure if I want to), but here are my thoughts:

• The reason why I would do this is isolation from noise coming from the router. So my question would be if the receiving FMC is actually any better in terms of noise than a standard router. And which FMCs are better than which routers or switches? Arguably, the switch/router has to deal with noise itself coming in from a number of devices connected to it and thus might be inherently noisier.
• Does clean power on the receiving end make a difference? And/or on the switch/router?
• How much does cable EMI on the way influence the noise in the Ethernet case? Is that a factor at all, given that we’re talking about twisted pair cables that are rather well shielded, anyway?
• So RPis are rather susceptible to noise? But what about devices that are made to shield away the noise, like a Zen Stream or any other dedicated audiophile streamers? Has anybody tested if it makes a difference there? I’d hope that the difference is much smaller, at least?

 

post 24

 

Thanks, I had read over the paragraph with the Zen.

 

Here is my experience. Switching power supply wire of router run many times thru ferrite. (yes, audible). Then send ethernet to switch with that switcher PS wire also run through ferrite. (yes, audible). If I could get the right end connectors perhaps an iFi supply would make it sound even better, but alas my router and switch use tiny connectors.

Data comes from Ext Spinning drive shared via win 10 desktop. The switch is on the other side of the room with short cable to playing computer using jriver. I did try a second switch right after the router but that did not improve things. Finally, went to short CAT 8 Cables from desktop PC to router and at the switch to connect to the playing computer. Audible benefit vs the CAT6a that was being used. Still have a 30 foot run of CAT 6a from the router to the target switch that has not been replaced.

CAT 5e, CAT 6a are not shielded in their standard configs. There is a shielded version of CAT 6A though, but I never used it. CAT 7 is shielded but really is normally terminated with a different connector and is a bit of an outlier.

CAT 8 is shielded and the bandwidth is improved along with alien crosstalk, NEXT (near end crosstalk) and return loss. I did not think it would make a difference, but it did.

 

As a networking guy, and an ostensible audiophile, this is my opinion, so take that for what it is worth. Network equipment and audio equipment are primarily designed for two entirely different things. Network equipment at its core is designed to deliver a stream of ones and zeros quickly and without errors. That is all it has to do (setting aside routing and packet filtering which are just purposefully manipulating that stream). Audio equipment has to produce wanted sound, whether from a digital or analog source, and in doing so avoid the propagation of unwanted sound. You can use a cheap SMPS on your switch. It won't affect the stream of ones and zeroes, but it may create audible noise that would not matter otherwise. Likewise you can make your router part of your ground loop. The bitstream will still flow, but it may also add a signal you can hear. I can't speak to the efficacy of network equipment specifically targeted for audio, but it does make sense that things like cleaner power and opto-isolation, even if they don't matter for the pure networking aspect, would be beneficial in an audio application.

 

Your comments reflect my experience. In fact, I was considering a fiber run from my router to my best system, but that got me thinking more critically about clean power. I realized that there were a couple switched supplies on the same house circuit as the stereo. A quick look on the oscilloscope showed they were a lot noisier than my linear supplies. I was able to move things around and get the last of the switched supplies out of that system and did find a noticeable audio improvement. The thing about noise is that you have to get it all to see an improvement. The last step was building a Jean-Paul linear supply for the RPi under the Pi2AES and the sound improvement was a strong step forward. It pays to go after the noisiest part of your system first, if you can figure out what that is.

After this process, I'm less interested in fiber and more interested in building quiet power for everything I can.

 

Fiber may be an easier route for those less technically inclined

 

You can also try an iso transformer on switching supplies if you’re really set on eliminating them but it isn’t practical.

Keep in mind some LPS’es can measure like crap, too, especially some of the Chi-fi/AliExpress variety. I’ve cleaned those up in the past by putting LT3045 DC to DC regulator boxes in front of them - cheaper solution than buying some of the $$$ Audiophile LPSes.

 

That's been a hypotheses of mine for a long time. Your experience makes me want to follow in your footsteps a bit more aggressively.

 

I was upgrading the last of my "dumb" switches to a UniFi switch and took the opportunity to run fiber to my Pi2AES. I picked up the 10Gtek fiber to RJ45 box and ran a short Cat6 patch to the Pi2AES. I am feeding the 10Gtek box with one of the older iFi PSUs running through an Atomic Bob Noise Nuke.

I was interested but a bit skeptical about the audible difference this would make and did it on a lark - it was a totally reasonable cost for the SFP to RJ45 box and a couple of sfp fiber transceivers. Colour me impressed. Everything is a good solid tick and a half easier/smoother, and a half tick more spacious sounding with headphones.

Running W11 Roon->UniFi USW-24-> SFP to Fiber Transceiver directly from the switch->Fiber LAN->10GTek SFP to RJ45 + PSU tweaks->OG Pi2AES + PSU tweaks-> Geshelli 4499 J2 w/ Sparkos OP Amp + PSU tweaks->Lyr+->ZMF Classics. Glorious.

Edit: On my Genelec + Sub work monitors the fiber LAN + PI2AES is a marked improvement over copper LAN and USB, too. Best spent audio $60 ever.

Testing setup pic.

 

Maybe this is another poll but I'm curious how many of the people that felt fiber improved sound were going from ethernet to fiber versus how many were going from wifi to fiber? My simplified thought is that wifi is a noise isolation path similar to fiber. That said, I have read that wifi and ethernet have different but roughly equal noise risk.

 

I finally took the jump from wifi to fmc- @lehmanhill

I also had thought that wifi is noise-proof (in my head it was) and I didn't want to complicate the whole set up. I decided to try if out as I have been reading this thread and it seemed that everyone has positive experiences. I got an etherregen for a good price and that broke any left over resistance.

I have to say that the transition is impressive - the chain is now router > tplink fmc> fiber optic cable>etherregen SFP port > etherregen output on other side > pi2aes >Yggdrasil a2> vintage amplifier> speakers. For all these extra interconnections - I think I have better and wider imaging, better center imaging (which is a weakness of my speaker) and a slight richness to vocals which was immediately noticeable. I am almost upset that I didn't try it out a few years ago.

 

@lithium - Thanks. That's very useful. Your setup is close enough to mine that I think the results should carry over.

 

Firstly thanks to Kernel Kurtz for the primers that made choosing what I needed easy.
I was already convinced as I ran a switch before the Pi streamer and it helped. This seemed worth a go and is a much larger improvement.
From the Pi hat to the DAC is optical so any ethernet noise is purely in the digital bit which is where it becomes very difficult to see how it would matter.
Still tempted by the F**k no option!
Running the converter at the Pi end off a USB power bank which is better than the supplied SMPS. UTP cable rather than shielded for the galvanic isolation.