Benefits of a premium Ethernet cable

[John Gallup]

In my current setup, digital music from a Roon ROCK NUC server travels through an Uptone Audio EtherRegen and a short link of fiber, thence to a long  stretch of ordinary contractor-grade Cat 5a cable, and finally to a dCS Bartók streaming DAC.

At substantial effort and expense, I could rearrange things so the final lengths of Ethernet (maybe 60 feet) would be replaced by a single run of something like an Audioquest Vodka Ethernet cable. I'm wondering if anyone has experience of whether this is worth the trouble and expense. Well mostly the expense; the "trouble" is the hobby part of it.

FYI, I posted this question on Audiogon and got a few useful suggestions amid the usual "bits are bits" flame wars. Thought I'd see if anyone here had some useful experience.

[BKDad]

Let me provide my two cents.  Or,  maybe, less.

In the lab I used to toil in prior to becoming a full time home scientist and audiophile, one of the things a few of the guys worked on was those fiber optic terminals used in CATV and telco systems to provide a digital connection into homes and small businesses.  Passive Optical Networks, as they're often called.  So, Ethernet connections were everywhere for testing these products and new chipsets.  

One of the accepted facts was that wired Ethernet connections were inferior to those made with fiber.  It wasn't because the bits themselves were any different at the receiving end.  Most Ethernet protocols have so many error correction mechanisms built in that it's hard to get the bits wrong.  The problem is that wired Ethernet connections are, well, wired.  That means that they support all sorts of undesired transmission of common mode currents and picked up noise.  This garbage inevitably gets into the terminal equipment and makes life hard for that terminal equipment.  Glass is nonconductive, so that problem is moot with fiber.  So, when anybody wanted consistent test results they used fiber based Ethernet.

Ethernet systems usually have some level of common mode isolation because transformers in the Ethernet connections are often used to isolate the various pieces of equipment.  That's not only for noise reasons, but also for electrical shock reasons.  You can read more about that all over the internet.  While these transformers are excellent for safety purposes, they're only fairly good for noise isolation.  Not like glass.  Hey - there's a reason that there's so many error-correcting mechanisms in the Ethernet protocol.

Various electrical cables will change the characteristics of the noise pickup and common mode transmission.  But, they can't do much more.  They're like different sewer water compositions compared to spring water.

You can actually measure this, at least for the lab gear.  I never even tried to measure it for audio gear.  (I don't do streaming at home.  Because, well, because.  It's not my cup of tea.  That's just me, however.)  I suspect that common mode currents carried over wired Ethernet in an audio system probably sound a lot like common mode currents carried over USB connections.

So, as one Audiogon poster suggested, I'd consider going as far you can with fiber.  Then, if you want, use something like that EtherRegen to finally clean up the signal before connecting to your DAC.  Use a good "linear" supply to power that fiber interface.  It may not have to be super expensive, but you do want the benefits of transformer isolation from the AC mains that you can't get with most commercially available switching wall warts.  That would be my approach.

That's the two cents.  Please note that I've never seen a product like an EtherRegen, so I'm not endorsing or condemning it.  But, it is a product you already have and use.

BTW, as I alluded to earlier, this same sort of issue exists with USB connections.  I do have measurements and plots taken here in my own house of USB common mode currents and their effects.  It's amazing how much junk there is.

[John Gallup]

Thanks for taking the time for this thoughtful and helpful response.

[TomicTime]

i use a 10 meter run of fiber between converters ( Small Green Computer ) and very short Audioquest ethernet from switch to first converter and same from downstream converter into Nucleus. Wholeheartedly agree with linear supplies  and a seperate power conditioning box for digital bits…. hope this helps…..

[BKDad]

4 minutes ago, TomicTime said:

 and a seperate power conditioning box for digital bits…. hope this helps…..

That's a great point that I should have mentioned.

In our USB sourced system, I individually isolate all the AC mains connections from each other using a filter system of my own doing.  The idea is to minimize the paths for common mode currents between the different audio components.  I also have what I'll call "DC filters" that provide similar filtering for the DC feeds from the linear supplies for the source computer and some other pieces like the USB isolator.  These really clean up the sound up as well.  The best analogy I can use is that instead of changing the color of the glop on your window into the sound, they instead wipe it cleaner.  Whether you prefer that's to your own taste is a different question you need to answer for yourself.

Similar products for the AC side that I've read about online are:

 Isotope Aquarius

ISOL-8

Again, I've never seen  these products but the description on their webpages appear similar in concept to what I'm doing.  No idea how well they've executed this.  But, their descriptions are worth a read.  I believe there's also a couple other similar products available in the USA and the UK.

BTW, the idea behind this is analogous to one of the big reasons why balanced interconnections and balanced circuit sound better.  But, even the best balanced circuitry has limited common mode rejection in the audio band and they struggle to maintain that performance above the audio band where a lot of the digital signal junk resides.

BTW 2 - I've had really, really good results with Curious USB cables.  I see that they offer Ethernet cables now.  Again, I've never used the Ethernet cables.  But, they might be worth considering.  Don't spend money on the suggestion of some stranger (me!), but I am always happy to show people options.

This paper might be of interest.  Ethernet and USB cables are really higher frequency versions of the cables the authors describe.  So, the effects are more severe.

SCIN

 

[GdnrBob]

I am pretty heavy into Digital, mostly for the convenience. I have no technical experience/knowledge-Just Trust the Ears (or, Trust Someone with Better Ears-you know who you are). That hearing enabled person mentioned getting things as simple as possible. This includes the LPS(Linear Power Supply) driven addons that most Digital Tweak companies offer.

I am leaning towards their opinion.

Using LPS just adds another layer to the mix.-Often with unknown benefits/deficits.

B

[TomicTime]

i have probably been involved in 50+ replacements of switch mode power supplies with quality linear supplies, i can’t think of a single case where the wall wart or even a hyper well engineered NAIM SMPS wasn’t easily trounced sonically by even a modest but well engineered LPS ( Pardo for example )…… 

of course we all have different circumstances… hearing, electrical systems, resolution of the gear… and religious belief…

[BKDad]

To be fair, it really is possible to make a low noise switching power supply that does the job we want.  In some ways, it could even be better performing than a linear supply.  They are used in test equipment all the time.

These better ones are not what is supplied with most audio equipment.

Good low noise power supply design is hard.  Low noise switching power supply design is harder.

Edited October 26, 2023 by BKDad

[TomicTime]

so far i’ve run across one in digital audio in a 3 component stack from a Greek company…. $60 k…. but even they solit the baby w mix of SM and linear…..

[BKDad]

I believe you.  As I said, it isn’t easy or cheap.

Rectification of AC signals is inherently noisy.  Some schemes less so than others.  It’s a series of trade-offs between size, weight, efficiency, complexity, and everybody’s favorite - cost.

There’s a Japanese company - I forget the name - that makes a line of really low noise switching power supplies aimed toward audio and medical applications. They might be pretty good.  Guess what!  They’re expensive.

[John Gallup]

10 hours ago, BKDad said:

As I said, it [AC rectification] isn’t easy or cheap.

Got one of these for the Roon server, NAS, FMC, EtherRegen. Not cheap indeed but has lots of output capabilities.

[BKDad]

Pretty nice unit.  I have an earlier model powering my music server, for the moment.

The only limitation is that none of those outputs are really isolated from each other.  That means that there is a common mode current loop - often called s ground loop - between all the devices powered by that one power supply.

That may not be ideal.  Kinda defeats some of the reasons for EtherRegen and FMC, amongst other things.

But, hey…. If it works for you, that counts for everything.

[Holmz]

On 10/26/2023 at 9:47 PM, BKDad said:

… Rectification of AC signals is inherently noisy. …

At some point a battery might make sense.

[BKDad]

25 minutes ago, Holmz said:

At some point a battery might make sense.

They have their own issues.  Including maintenance.

But…. My first really successful digital audio system used four SLA batteries for the analog sections and a single one for the digital in the DAC.  That transformed an OK but not great sounding CD transport and DAC combination into one that was comparable to, albeit somewhat different from, the vinyl playing turntable.  That proved to me the value of electrical isolation.  Digititis?  What digititis?

I am amazed how little emphasis is placed on isolation in commercial digital products.  Most efforts are incomplete and pretty token.  Mostly marketing.  Of course, that has molded the market into not believing its value.  Kinda like people being convinced that time and phase performance doesn’t matter with loudspeakers.  Distorted waveforms are distorted waveforms…

[ctsooner]

I’ve had so many of the digital clean up products in the house over the years.  Many did what they said they would (lower noise in the system).  I have finally found that Waversa products have scratched my itch. They are passive and easy to install in seconds.  They just work and are in all price ranges.  I am finally at that age where ease needs to be taken into consideration, lol.   

I’ve also noticed that the better DAC’s often have a lot of built in noise reduction.  Some companies use expensive boards that have isolation etc built into the board itself (it helps, but isn’t a total fix).