Sound Quality Ethernet vs AES/TOSLINK

Hi, sorry if this has been covered before, I have searched but didnt find an answer, but would feeding a Roon endpoint via ethernet or something like TOSLINK make a difference in the sound?

For example, there are streamers that take great care in lowering noise so that the digital signal is clean, but isnt ethernet inherently superior in so much its using error correction?

Ethernet and Toslink are galvanically isolated so that electrical noise in a computer is isolated from the streamer or DAC.

Ethernet doesn’t have error correction of itself [Edit: This is incorrect, see below], but the TCP protocol has asynchronous transmission that will resend a packet if a checksum shows it wasn’t received intact. I understand this rarely happens in a wired home environment.

The below comment is per Ted Smith over at the PS Audio forum (who is truly an expert in audio).

“24/96 is the theoretical limit of TOSLink (it was designed for 48k) Still there are a lot of transceivers out there that, with good cables, can reliably pass 176.4k or even 192k. None (or almost none) will pass 352.8k (DXD and/or double rate DSD via DoP.)”

That said, it seems Ethernet will allow for a higher transmission rate. Will you be able to tell the difference? Can’t say…

TOSlink is always isolated from ground loops… ethernet is not if you use a shielded ethernet cable where the shield connects grounds of devices on each end… There are some exceptions like the Blue Jeans Cable Cat 6a which uses Belden 10GX series Cat 6a, with it’s floating shield design.

Some helpful quotes from HQPlayer’s @jussi_laako (who knows a little about networked audio) on CA Forum:

Boring standard CAT6 UTP cables work just fine, since you get transformer isolation at every connector. Problem with STP cables is that it allows ground currents because the shield connects grounds of two devices, so it can be used only in carefully ground controlled environments.

STP cables which many audiophile network cables are, create ground links through the shield and thus spoil the galvanic isolation it would otherwise provide (because ethernet is transformer isolated by default).

When people ask me when they can use STP, my answer is generally that within a normal machine room 19" racks that are carefully grounded to a common ground using at least 4 mm2 copper wire and all equipment is powered through 3-pin IEC power from common power feed.

Hi Andy, the data link layer (ethernet in this case) actually does have some error correction with via CRC check… However, I agree that ethernet should be superior as digital is converted to ethernet frames and we know empiracally that mild electrical noise from local electronics has zero impact on this bit conversion to frames, and as you say the eithernet cable is galvanically seperated.

So it should be a no brainer?

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Hi Sean, suspect ground loops are totally irrelevant. Ethernet cables facilitate the transmission of frames, the frames contain the data, the conversion from ethernet frames back to the original media is bit perfect, we know this 100%, it works every time unless there is some hardware issue. The internet would not work at all if ground loops were somehow impacting the reliability of data transmission.

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You said:

"and as you say the eithernet cable is galvanically seperated".

The info I shared is highly relevant to your statement there… Have another careful read…

And I made no mention or even hint, of dropped bits…

I remember when I re-did my ethernet cabling a couple of years ago, Blue Jeans Cable suggested Cat 6 over 6a due to issues associated with the shielding. @dabassgoesboomboom

What issues specifically? As usual the devil is in the details…

Sounds very different to my communication with them and with Belden about that Cat 6a cable… not that I have any of it myself but it does break the ground loops.

Really easy to verify too… I’ve hacked one open… the shield is disconnected at both ends…

Until you get one…cabling is a crazy unpredictable thing.

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There is no GND on an ethernet cable, it would be insane to connect all network hardware together via a common ground via ethernet. The cables are electrically isolated in respect to ground.

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They sent me a document outlining advantages. I’ll see if I can find it…been at least two years since I recabled.

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No it isnt !!! The is computer science, we know exactly how it works, its not mumbo-jumbo hifi territory where no one has any idea of how anything behaves… We know exactly how ethernet behaves.

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There may be no advantages for typical home use but I’d be more interested in the disadvantages since you mentioned "Blue Jeans Cable suggested Cat 6 over 6a due to issues associated with the shielding."

I’d be keen to know about any issues associated with a floating shield where you can very easily see with your own eyes (if you hack one open) the shield is disconnected at both ends.

If there are issues, it must be something not related to ground loops. I’d be interested to know, for learning purposes @rrwwss52

Lol… snake oil… use this platinum plated CAT 6 cable… sheesh, what utter rubbish. People, just buy regular ethernet cable, dont fall for any of this nonsense.

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Not sure what you’re on about… Blue Jeans Cable Cat 6 and 6a cable is based on Belden 10GX series Cat 6 and 6a cable…

No worries Margo. Best of luck with the discussion.

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The cable, so long as it is functional will have zero impact on the sound. NONE. If cables had an impact on the data transmission, then data centres (of which I have built in the past) would be very specific about the cables they use - I can tell you now, theyre not.

For the pin layout of ethernet, see https://www.electronics-notes.com/articles/connectivity/ethernet-ieee-802-3/cables-types-pinout-cat-5-5e-6.php — there is no ground.

STP can have a shield though, right?

If the shield connects to the ground of the devices on each end… you have a potential pathway for ground loops…

I use Blue Jeans Cable Cat 6, and a few Pangeas. The BJCs have certification reports attached. No platinum stuff here.

Oops: I do have a Wywires Platinum headphone cable for my Ether 2s…

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I dug through my stuff, and couldn’t find it. Just changed computers, might have got dumped. If memory serves me, it had to do with the shield picking up interference.

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