I have earlier posted about Audio trends and snake oil. What annoyed then and still today in marketing and media that too often today then talking on hi-fi, science is replaced by bizarre belief structures and marketing fluff. It seems that there too many snake oil rubbish products marketed in the name of hifi. It is irritating to watch the stupid people in the world be fooled with things like exotic materials, directional cables, thousand dollar IEC power cables, and all that rubbish. “If you pay ridiculous money for these cable you will hear a difference, but don’t expect your friends to”
I can agree that in analogue interconnect cables there are few cases where better cables can result in cleaner sound. And there are very many cases where there is no objectively noticeable difference.
In digital interconnect cables story is different than on those analogue interconnect cables. Generally in digital interconnect cables the communication either works, does not work or sometimes work unreliably. The digital cable either gets the bits to the other end or not, it does not magically alter the sound that goes through the cable.
But this digital interconnect cables characteristics has not stopped hifi marketers to make very expensive cable products that are marketed with unbelievable claims. Ethernet has come to audio world, so there are hifi audiophile Ethernet cables that do not make sense to me. With Ethernet the data either gets through the cable without any changes to it, or it does not get through at all. Ethernet has checksum on every data packets to detect for any errors (which are rare) in the transmission and all the packets that have data changed in any any way are discarded. So Ethernet cable can not not magically slightly alter the digital sound that goes through the cable.
Here are links to two articles on such expensive audiophile Ethernet cables:
Is streaming cable more or less expensive than $1000 audiophile snake-oil ethernet cable ?
https://audiobacon.net/2019/11/02/the-jcat-signature-lan-a-1000-ethernet-cable/
Gallery: We tear apart a $340 audiophile Ethernet cable and look inside
https://arstechnica.com/gadgets/2015/07/gallery-we-tear-apart-a-340-audiophile-ethernet-cable-and-look-inside/
Apart from the absurdly high price tag and more mechanically robust connectors, I see nothing special on those cables for carrying the data signal. I suppose those does look quite attractive to some users and this makes them willing to pay the high price.
Despite the fact that some people desperately want there to be audiophile Ethernet cables, there simply is no such thing. The IEEE standards do not include a superset of specifications that make a regular Cat-7 cable into an “audiophile” Cat-7 cable. If you still believe those “audiophile Ethernet” cables sounding better, please inform yourself how an Ethernet and Ethernet cable works.
133 Comments
David Salz says:
Lots of consumers buy products that fail to provide value based on the most logical criteria and there is no doubt that many upgrade audio cables are purchased simply for their visual aesthetic. On the other hand, some of the most respected audio engineers in the world, including Bobby Owsinski, the leading author of audio engineering books, purchase expensive upgrade cables for use in their own studios. These include analog, digital and power cables. Your technical argument is wrong, because cable related issues of noise and waveform integrity create complex interactions in audio systems that affect music reproduction. People are usually very surprised by the changes they hear when swapping Ethernet cables in a high fidelity music system. Furthermore, local solid state drives usually provide substantially better fidelity than network drives. Upgrade Ethernet cables can provide value by reducing that loss of fidelity.
Tomi Engdahl says:
“Your technical argument is wrong, because cable related issues of noise and waveform integrity create complex interactions in audio systems that affect music reproduction. People are usually very surprised by the changes they hear when swapping Ethernet cables in a high fidelity music system.”
The answer to subtle difference of sound due Ethernet cable differences moving data bits differently cause sound to changer is no, unless you want to believe those who make big money by persuading people otherwise, or those who fell for the emperor’s new clothes. Digital is quite simply different from analogue: the signal gets there or it does not.
There could be some differences on on the electromagnetic noise being coupled to the cable and sometimes going though the equipment to output of the device is not well built.
Tomi Engdahl says:
Your cable page says
https://www.wireworldcable.com/phone/digital.html
“Starlight 8 Ethernet utilizes an innovative flat and parallel twinax conductor geometry that supports extreme transmission speeds and reduces noise for the most lifelike reproduction of streamed music and video. The patented Tite-Shield™ design has twelve internal shields that isolate noise for improved sound and video quality. The official network cable categories (ie. Cat5/6/7/8) only include twisted pair cables, so these non-twisted twinax cables cannot be rated by those test specifications.”
How this specifically helps to make audio sound better?
When I have worked with pro audio systems, I have had two cases where changing Ethernet cable has had noticeable effect:
1. A broken Ethernet cable cause network connection to on and off. Sound breaking or no sound at all. Decent basic IT cable fixed it.
2. A shielded thick CAT6 cable caused humming noise to system. Using a cheap unshielded CAT 5e patch cable solved the ground loop problem that caused humming.
Tomi Engdahl says:
From
https://forum.audiogon.com/discussions/ethernet-cables-do-they-make-a-difference
On the LAN datatransfer is usually limited by the network cards of two connected devices. Most oF NAS do not support 1G.
If any of the devices in your LAN route from the storage of your audio file to your playing device is 100M – your entire connection is limited to 100M. Any cat5 cable will serve you as good as the most expensive cat6,7,8,9,10 whatever number you can come up with and willing to pay for.
Do yourself a favor and run a couple of tests:
1. Time one audio file copy over the cheapest network cable you have and compare it to the time of copy over the most expensive one. I bet they will be the SAME, and much less than duration of the audio track – conclusion: network is not a bottleneck.
2. Copy the same file file over to the playing device (computer or whatever) and compare playing it to playing from NAS. I bet you won’t be able to tell the difference.
Alternative approach – do the blind test and try to guess if cable is cat5 or cat.
Did anyone do a blind test?
Please post your honest results.
It would be nice to see “placebo effect” eliminated.
Tomi Engdahl says:
From https://forum.audiogon.com/discussions/ethernet-cables-do-they-make-a-difference
Yes, they make a difference, but not because “bits is bits”. The last meter, I have been told, improves EMI rejection. Regardless of the science, I hear a difference.
However your digital signal, especially from file source (NAS or streaming server) is a different story. Media player cashes the digital information as it comes from the source over the network cable and has enough bytes to play “smoothly”. Network protocol takes care of packages transfer, ordering, re-sending lost packages (if any) and so on. Digital data is sent in discrete packages – that is defined by TCP/IP protocol. No cable can change that, Media player converts bursts of data into contentious stream of digital data over the optical cable (for example) to DAC.
With digital data transfer – your system is as weak as your weakest link and weaknesses do not usually add up.
p.s. reasonably priced good looking cable is worth the money just for it’s look and high quality of the connectors.
p.p.s. Each of us can define “reasonably priced” for themselves
They make no difference. None. Zilch. Nada. Spend your money elsewhere in your system.
You are streaming 1’s and 0’s. If you hear music, they are getting there. Period.
The 1’s and 0’s are turned into ANALOG by your D/A converter, and THAT matters, but the quality of the cable that delivers the 1’s and 0’s only needs to be sufficient to get them there without loss.
Any cat 5e or 6 cable is sufficient for audio use transmitting a digital signal. Cat 6 is what I use and what I wired my entire house with since it supports 1GBPS speed.
Anyone who tells you that ethernet cables make an audible difference in the digital domain does not understand digital data transmission and /or they are trying to profit from your ignorance. The same is true of digital Coax and Toslink (optical); the signal either gets there or it doesn’t.
Tomi Engdahl says:
MUSINGS: Audio Cables Summary, Non-Utilitarian Functions & Scientific Falsifiability
http://archimago.blogspot.com/2015/06/musings-audio-cables-summary-non.html
MEASUREMENTS: Ethernet Cables and Audio…
http://archimago.blogspot.com/2015/02/measurements-ethernet-cables-and-audio.html
Which brings us to the concept of “audiophile ethernet cables” (see here also, and recent mainstream press exposure of the “madness”). Let me be clear. If I have issues with USB cables, or SPDIF cables, making any significant contribution to audible sound quality (assuming again essentially error-free transmission of data), there is no rational explanation whatsoever that ethernet cables should make any difference. The TCP/IP protocol has error correction mechanisms that allow for worldwide transmission integrity (otherwise Internet financial transactions should be banned!), and is asynchronous so there is no temporal dependence on exact timing mechanisms (jitter not an issue with adequate buffer to reclock and feed the DAC). So long as the “protocol stack” is functioning as it should between the devices, there will not be any issue. Systematic errors causing audible distortion either means hardware failure or poorly implemented communication software. Therefore the expectation if we were to test or “listen to” different ethernet cables is that there would be no difference.
Since I like to make sure objectively, let us at least run a few tests to see if indeed evidence can be found to support the hypothesis.
IV. Summary / Conclusion
I believe if there indeed is an ethernet audio device that “sounds different” because of different cables being used, then that device should be returned because it is obviously defective. Remember folks, it is like accepting that the earth is spherical or that 2+2=4 – because that’s just the way it is. Ethernet communication is an engineered system, the parameters and capabilities of this system is not only understood but designed to be the way it is by humans! You really cannot claim to have “discovered” some combination of dielectric or conductor or geometry that works “better” within an already errorless digital system unless you’re claiming improved performance outside technical recommendations (in the case of Cat 6 for gigabit networks, it’s 100m or 328 feet lengths within a reasonable ambient electrical noise environment).
It’s also worth remembering that audio data bitrates are quite low. Today, I hope nobody is running anything slower than 100Mbps “fast ethernet”.
Ultimately, I’m not suggesting anyone use the cheapest ethernet cable he/she can find. If you like the esthetics and build construction, go for it! Just realize that it’s essentially impossible to argue that a functioning (free of data transmission error) ethernet cable will “sound” any different or worthy of significant cost differential based on sonic quality. The idea of specialized “audiophile” ethernet cables (or “ethernet switches” for that matter) is plain nonsense.
For the record, subjectively, I have never heard a difference between ethernet cables on my system.
Well, it looks like Chord got their hands slapped for claims about sound quality with their ethernet cable ads determined to be “misleading advertising”, lacking in “substantiation”, and “exaggeration” in November 2014. Bravo to the UK’s Advertising Standards Authority. Truth is important.
Bottom line: There’s no evidence that any of the digital cables make an audible difference be it TosLink, coaxial, USB, or now ethernet within an error-free system.**
As usual, if anyone feels that I am in error, please demonstrate and leave a link to the evidence.
Comments:
Yes, indeed any low-level noise will not corrupt data.
But some folks still have this belief that the noise carried within the ethernet cable itself can creep into the DAC and cause noise floor issues (presumably). I wanted to demonstrate that with what I believe is a reasonable high-resolution streaming solution (Transporter playing 24/96 with the ethernet cables directly plugged into the device), these concerns were unfounded.
Furthermore, whatever concerns people may have about long cable lengths (like 50-feet), I could not detect any difference either…
What intrigues me about the idea that digital cables sound different, is the way in which those differences are described, by those who hear them, in audiophile terms. Quite how data can be re-arranged in a cable such that ‘the soundstage can be opened up’ or ‘percussion sounds more lifelike’, or whatever else is heard, is quite amazing. As one of the poster’s in a link above put it, “perhaps the 0′s are more rounded and the 1′s are straighter”.
Now as to the subjective descriptions… That of course opens up the whole field of psychoacoustics and the importance of controlled conditions when doing subjective evaluation! It doesn’t help of course when some audiophiles feel controlled tests like DBT’s are not valid…
As for “rounded” 0 and “straighter” 1′s, here is a beautiful example of analogue thinking in digital *data* transmission! Obviously the writer does not understand the technology to speak in this fashion. Overly “round” 1′s or overly “straight” 0′s would at some point hit a threshold and be misinterpreted leading to data error. We have no evidence anything like this is happening. I therefore cannot take this writer seriously when it comes to technical commentary.
For a moment, suppose I did measure AudioQuest ethernet cables and imagine if (most likely) they did not make any difference objectively. What happens when the Super-Duper-Audio releases their Cat 8 ethernet cable with silver conductors, Ultimate (TM) shielding, and Mega-Hyper-Tesseract (TM) geometry? Do we need to also measure those before we can dissuade certain audiophile beliefs of the “faithful”? IMO, obviously that would be perverse. It’s more important to educate folks to understand how things work and extrapolate based on understanding, developing critical ability in the process. This IMO is the higher calling of those who call themselves “journalists” in the audiophile press and formal blogs rather than ending up being the cheerleaders. And ultimately the onus of proof should be on Super-Duper-Audio to show the audio consumer why their product is better and worthy of whatever price the item may “command”.
Until someone is able to demonstrate that there actually are timing irregularities which would cause a significant change in the characteristics (like some kind of actual jitter test coming from a reasonable DAC), I think there are no worries. Just theoretical possibilities. I have seen the jitter anomalies from DACs and source players, but I don’t think cables are cause for concern…
Tomi Engdahl says:
https://forum.psaudio.com/t/ethernet-cables-and-sound/11297/11
BER is 10E-10 for ethernet. But a very rare error won’t change the continuous transfer of data and thus the sound. Errors aren’t the issue, if there even is one. Until a bit sees a DA, it has no sound.
As an “RF Guy” working in IT because it pays the bills. I’ve seen some of the most piss poor cabling in main distribution frames (MDF) & intermediate distribution frames (IDF). How do they successfully transport all that data and yet Audiophiles insist on megabuck Ethernet cables because it makes a difference. I just use good ‘ole CAT 6e shielded. CAT 7e is the best but only if you really need that much shielding.
Analog cable has several ares where changes in the cable can alter measurable attributes that superimpose go distort the signal in various ways. This is the nature of analog,
Digital, too, has measurements that define how much the “analog” signal in the guise of a square wave is distorted, I agree. But, digital. Isolates the signal to a one, or a zero. We only need the fine, answer to be the correct one or zero that it was when it left the far end of the wire.
This is what is so nice about digital. We break up the signal into easily identified pieces. Sure, the smaller the piece the better it is built back. Those fundamental pieces identified right REMOVES the cable from the “sound”.
Sure, if we mis identity the bits, we hear clicks and pops, or error circuits fills the gaps with what was being played immediately before. That does not change the tonality and timber of the music though. A persistent and continuous analog “distortion” does that.
Moving bits from A to B is pretty transparent to the external cable. A change in sound means SIGNIFICANTLY different PWM bits are comprising the finalsignal. To digital, this is a BIG change, and would trigger all sorts of detection and correction errors. The DA filters can, and do, change the musical timber and tone. But this is the analog domain now.
How are we changing the data between point A and B such that a CONTINOUS change in tone and timber are now encoded, and go undetected as errors in the Ethernet link to be corrected?
I’ve designed digital Ethernet cables for 25 years, and kind of know how to make sure the bits are the same at each end. Same, same is really good, and why digital can be so good, too.
Differences in theoretical errors on cable, yes, but differences in the sound? What are the underlying reasons we think we KNOW digital is as fragile as analog for signal integrity?
Don’t say, because (same as no answer), or jitter (We reclock the data to re-set the pulse width).
Trying to define real reasons for the signal at A turning into, digitally, an entirely different signal at B. Noise is not it. Noise won’t, and can’t, change the PWM modulated initial signal encoding into a different animal. Errors, yes, but those aren’t a continuous change in the signal.
It is BER. Same data means the same sound UNTIL the DA filters. There we can have some discussions.
Objectively – no, subjectively – depends on you and your environment
It depends on your environment, electrical, RF. If the data is getting there now without too many retries replacing the end patch cables shouldn’t make any difference. If you have poor terminations you may see some improvement. I would convert to optical at the last step if you can as this will guarantee true galvanic isolation
Here is where noise can be a problem, it isnt the effect on the Ethernet accuracy, that remains bit perfect except under the worst of sitations, it is the effect on the system clock. The system clock controls the digital interpolation coming out of the DA block. A bad clock introduces jitter and non linear quantization noise in the X and Y axis. This moves the closest, and most accurate, value with respect to time and amplitude.
This clock error is what impacts the sound. It is feasible that different Ethernet cables COULD introduce noise that MIGHT effect the system clock. A galvanic isolator might mitigate the issue if several things are true; the cable even has noise on it, it gets past the filters in the NIC card and it gets into the system clock circuit block…past the built-in noise safeguards in that critical block.
This isn’t the “sound” of an Ethernet cable. It, if “it” is really happening, is the sound of the system clocks response to noise induced quantization errors. And the noise is assumed to be there, and introduced by the Ethernet block.
This could be proven with noise injection and detection on the system clock. Are we really after a real problem, or failing to define that we have one?
The most critical item in digital are clocks, and I doubt that these are left to the wolves and with no significant amount of noise shielding. That jitter value? The system clock is where it all begins.
Galen
Noise is the biggest culprit in Ethernet cables: the noise that’s near the frequency of the Ethernet signaling won’t be attenuated much by the transformers at each Ethernet connection.
The higher the Ethernet frequency the more complicated it is to handle things so those computers make more noise.
There’s almost always a lot of noise in these frequencies coming from whatever your Ethernet source is.
The first thing is the DAC might be creating or reflecting noise back onto the cable and that noise along with any source noise might be affecting people’s systems via any groundloops (which are basically RF receivers) The (probably) very low level noise that’s picked up in any particular groundloop depends on the area of the loop. Bigger loops, more current noise is circulating in the groundloop.
The thing about RF noise is that any non-linearity in any connected circuit can modulate any audio frequency noise on the RF signal down into the audio band (e.g. a crystal radio, which is just a diode.) Guess what? Almost all of our equipment has diodes, transistors, etc. near the inputs and outputs. They, along with any other non-linear idiosyncrasies of a system can convert audio frequency modulations in any received RF into simple audio noise, perhaps right at the inputs, or perhaps it ends up modulating power supplies, etc.
How loud is this? It depends a lot on the system.
Tomi Engdahl says:
https://community.roonlabs.com/t/do-ethernet-cables-make-a-difference-in-sq/87775/2
Any basic, competently constructed ethernet cable is all one needs. The concept of audiophile ethernet cables is actually a bigger joke than almost any audio woo nonsense. Cat 6 is more than fine. Cat 5e is fine. Cat 7 if you have it is fine. Bad ethernet cables will cause problems, but they won’t be subtle “sound quality” changes.
Tomi Engdahl says:
Global feedback: can Ethernet cables make a difference?
https://darko.audio/2014/12/global-feedback-can-ethernet-cables-make-a-difference/
Audio playback from a digital source is similar to telling a joke: timing is critical.
In 2014, the new frontier of acceptance is Ethernet cables; an area of digital audio transmission where scepticism remains rife.
In the appropriately numbered KIH #13, Srajan Ebaen tackled the issue from the side. “Are you keeping an open mind or being taken for a fool?” he asked. Many an audiophile sceptic would have us believe that plonking down anything more than Monoprice money on an Ethernet cable is to be had by snake oil charmers. Maybe they’re right, maybe they’re not. Without actual listening no opinion, no matter how forthrightly expressed, can be considered definitive.
Besides, this Blue Jeans Cable editorial reminds us that many a CAT 6 cable doesn’t even meet the standard’s specifications.
Have we not been here before with USB wire?
It seems our respondents are happy with the idea that interconnects and speaker cables can make a difference but Ethernet, it’s “Nothing but snake oil, mate”.
Tomi Engdahl says:
Re: Ethernet Cables, do they make a difference?
https://www.dpreview.com/forums/thread/4415944
Yes and no. Yes because you don’t want to buy cheaply made cables. No because there’s no reason to spend hundreds on an cable that some marketing company hyped.
At the end of the day just get a good quality shielded cable and move on.
No, it won’t.
The only cables whose quality affects the sound are those that carry analogue sound. The music stream before the DAC is digital, meaning ones and zeroes, and the protocol they use for this is TCP/IP. That implies that even if that signal is horribly distorted, the pulses for 1s are still distinguishable from those for 0s, and the DAC will still produce the exact same signal defined by those 1s and 0s.
If a ‘bit flips’ during transport, the network interface on the receiving end of the cable will recognize that the checksum of the containing TCP/IP package does not fit, and discard the entire package. If too many packages need to be dropped (which would be around 99.85% of packages on a gigabit cable for a 1.5mb/s uncompressed wav stream ), the entire playback will be interrupted, but NEVER EVER will it sound different.
As long as it meets any standard, it is more important that the cable looks good in Your home.
In the digital world “audiophile” cables are a waste of money. As long as the “1″s and “0″s that go in one end of the cable arrive at the other end without changing then no amount of money spent on a “better” cable will result in any improvement.
Streaming audio is not audio, it is data. No different than any other kind of data, like a movie, photo or office document. If it is making it to your computer, then it is at 100% full quality. If it was anything less, it would buffer and stop playing. As long as the cable you have is connecting you to your network router at full speed, then it is a good enough cable.
Cat 6 exceeds the requirements for gigabit (1000Mbps) network speed, which far exceeds most internet connection speeds and is 700x more than the requirement for TIDAL’s bandwidth needs.
However, that is not what an Audiophile Ethernet cables is for. Some high end audio gear can use Ethernet cables to send signals between components. This is not a standard network connection, even though it uses a standard network cable. In this usage scenario, cable quality and shielding could potentially have a bit of an effect.
After years of working professionally with audio gear, I’m convinced that “special” audio cables of all types are nothing but a scam.
The thing about digital is this: it’s all or nothing. If the audio sounds more or less normal, then a better cable won’t help. Any deficiency in a digital cable will result in painfully obvious noise or silence (depending on the application that’s receiving the data and playing it). You don’t need a “golden ear” to tell when a network cable doesn’t cut the mustard.
Indeed, the real problem is the opposite: it’s actually hard to detect a flaky network cable that’s causing excessive data retransmission because the most common symptom short of total failure is simply reduced throughput. And since the data rates required by audio are relatively slow, listening is pretty unlikely to reveal the noise or gaps in sound that would reveal the problem.
Tomi Engdahl says:
Ethernet Cable Comparison – with music samples!
https://www.youtube.com/watch?v=fc80yCACkP8
Well… yes: we are comparing some ethernet cables this time. With music samples.
Std Ethernet 2:05
Audioquest cat700 Pearl. 5:06
Shunyata Venom 7:59
Shunyata Delta 10:48
Shunyata Alpha 13:54
Audioquest Cinnamon 16:53
Great, no difference as expected… save your money
Even though some people may hear difference, it’s just not worth the extra money over a standard cable IMHO. The first demo sounded just as good as any other (what I mean is, if you hear it you don’t actually miss anything at all).
Thank you to the creator for making this video. It took a lot of effort and I just want to say that I rally appreciate you taking the time to do this for everyone’s benefit. The fact that you don’t even try to press your opinion on others is great. Despite that, some of the comments are still so dismissive and smug. The whole point of the video is that if you think there are no differences, now your beliefs are confirmed. If you think there are., you are also correct. Listen and see. Life is not all magic nor is it all science.
I cannot understand why there cannot be a difference. Electronic devices are much more sensitive today and computer technology and live audio works much differently. Theoretically speaking, if the steaming renderer could cache the track enough and transparently recreate the file locally, there should be no difference.
It is all about common mode noise. We are working on an article with ‘proof’ / measurements.
That is great, is it that noise interferes data transfer or the noise is transmitted to the renderer and gets into the decoded analog signal?
One thing people forget about ethernet cables is while the data is digital, the signal is analogue and suffers from EMI and jitter effects. I definitely heard a difference on your compressed video even. The streaming application is time sensitive versus bog standard computer TCP/IP with retries and error correction.
Ethernet is quite resistant to emi especially any low levels in the home and jitter really isn’t an issue if the DAC is built properly. Most $100 chinese DACs with power bricks don’t even have these problems any more. AudioScienceReview has debunked a bunch of this BS.
Consumer audio brands selling ethernet cables. Just when you think you’ve seen it all… this comes along. As a certified ICT engineer … it’s bullshit. Just buy a shielded cat6a or 7 cable and you are fine. PS ethernet cables don’t need burn-in. not ever…
Thanks for going through the effort on this. I created a response video where I took the audio track and saved the 6 copies and randomly labeled them. Here is the response YT video https://www.youtube.com/watch?v=gebv9BUuNNQ&feature=youtu.be
Tomi Engdahl says:
Measuring Ethernet cables – Part 1
https://alpha-audio.net/background/measuring-ethernet-cables-part-1/
Ethernet cables. Since streaming has entered the world of high-end audio, we see ethernet cables from almost every manufacturer: Audioquest, Supra, Nordost, Shunyata, Chord, et cetera. But Ethernet is digital. And also package based (in contrast to spdif, for example). That can’t go wrong, can it? How is it then possible that we hear differences? We are going to investigate. Prepare for multiple parts. And no: we don’t have any answers yet. And we don’t know where this journey ends either!
Conclusion
We have not measured any differences in the digital domain for any Ethernet cable. UTP, Audioquest, Shunyata… all cables perform equally in the digital domain. Every bit in the sample is the same… literally: 0 difference. Take a look at the results in the screenshots.
But we still can’t conclude that Ethernet cables have no influence. After all, we have remained within the digital domain. And then something like jitter doesn’t matter. And ‘noise’ doesn’t really matter either. In short: what we have learned is that we no longer have to search in the digital domain: there is no packet loss. And there is no difference in cables as long as we keep working digitally: this is proven by exactly the same samples. And that also explains that in fact the rest of the network is not at all interesting when it comes to audio quality. Just upgrade the cable to the streamer. The rest can actually have no influence.
We wanted to take you on this trip. We will continue the search!
Tomi Engdahl says:
https://www.hifi-advice.com/blog/audiophile-insights/digital-insights/digital-cables-compared-usb-and-ethernet/
Tomi Engdahl says:
https://audiophilestyle.com/forums/topic/59556-alpha-audio-ethernet-cable-comparison/
Tomi Engdahl says:
HAARLEM
Ethernet Cable Comparison – with music samples!
https://www.youtube.com/watch?v=fc80yCACkP8
Well… yes: we are comparing some ethernet cables this time. With music samples.
Std Ethernet 2:05
Audioquest cat700 Pearl. 5:06
Shunyata Venom 7:59
Shunyata Delta 10:48
Shunyata Alpha 13:54
Audioquest Cinnamon 16:53
Great, no difference as expected… save your money
Audio science has all the proof anybody needs to prove many of these manufacturers are just taking people for a ride.
Ethernet Cable Mixup
https://www.youtube.com/watch?v=gebv9BUuNNQ
This is a response to TheAlphaAudio recording a track being played over 6 different Ethernet cables.
Tomi Engdahl says:
https://spy.com/articles/gadgets/electronics/ethernet-cables-for-gaming-1202753801/
In 99.9% of instances, any Ethernet cable that’s rated Cat 5e or higher will perform identically on the average home network for gaming. Assuming interference is not an issue, ping times should be the same. And while there are different tiers of Ethernet cables — Cat 5, Cat 5e, Cat 6, Cat 6a, Cat 7 and Cat 8 — all of them except for a Cat 5 cable are going to perform identically on your home network. And even for the purpose of gaming, the Cat 5 cable will probably be fine.
The main difference between Ethernet cables are the speeds that they’re rated for and the level of protection they have against interference. But because most online and cloud gaming requires speeds under 50Mbps, the speed rating of Ethernet cables for gaming is irrelevant. They’re all fine.
But where upgrading your Ethernet cables might benefit your gaming performance is when it comes to interference. If you have an older Cat 5 cable buried in a rats nest of power cords and HDMI cables and audio wires behind your TV, it’s possible it could be suffering from crosstalk which would affect network performance.
Tomi Engdahl says:
https://www.wireworldcable.com/phone/digital.html
Tomi Engdahl says:
https://6moons.com/audioreviews/interconnects/interconnects.html
Wire is wire, cable is cable. Too bad this statement is invalid. It’s all the more reason to dive into this matter a little deeper and attempt to understand what factors contribute to these audible if not always measurable differences.
Cables — and thus the species of interconnects we shall focus on in our listening tests here — are all susceptible to the laws of nature. This is where electrical, magnetic and mechanical values play their roles. Most of the time, an interconnect consists of a pair of cables where each leg handles a discrete channel. The need for both legs to be absolutely identical should be evident.
The only thing an interested layperson ever sees of an interconnect cable is its outside. Every supplier dresses — or better yet, cloaks — their cables in the most beautiful or at least most impressive looking mantles. The ends are terminated in various RCA or XLR plugs whose insides are often potted. The remaining available observation concerns the girth of the cable. This can range from just a millimeter to several centimeters. What is going on inside the fancy cable cover remains a closed book (safe for a few makes who publish cross-sectional graphics or photographs).
Upon taking a closer look at these conductors, we may find a single tiny wire or a bundle of complexly twisted, braided, layered, bundled or otherwise interwoven wires or wire groups wherein each conductor could be individually coated with insulation (Litz). We might find thousands of individual conductors in fact. At this level, anarchy rules and any imaginable geometry could be revealed.
Tomi Engdahl says:
https://audiophilereview.com/cables/more-mystifying-metal-madness/
Tomi Engdahl says:
Should those expensive hifi ethernet cables viewed more like art product than real technical solution for anything?
Fancy looking artesanal products sold with a made up story why they are better and maybe even sold with help of real life art performance “cable comparison” (pitching and some magic tricks to make you believe)
Tomi Engdahl says:
Pssst.. hey..look…the emperor…he’s got no clothes
Tomi Engdahl says:
expensive Audiophile Ethernet Switch..
https://audiobacon.net/2019/04/05/sotm-snh-10g-audiophile-ethernet-switch-review/
ha ha love how they talk about 0s and 1s being more complicated. Streamed content is buffered to deal with packet loss what more can you do
Tomi Engdahl says:
Truth about RCA signal cables
https://www.youtube.com/watch?v=QOagVDZLQnA
Here we discuss the circumstances of when it is appropriate to use a twisted pair RCA cable vs a Coaxial RCA cable.
Video comments:
The only problem is that nobody lists what kind of RCA input or output they have on their headunit or amplifier.
Take an ohm meter (DMM) and check the resistance from the battery ground connection on amplifier to the RCA outer ring on amplifier (with everything unplugged from amplifier). If you have less than 100 ohms it is a single-ended input.
Thanks Mr. D’Amore for the quality information. Always good to hear it from a quality engineer rather than from someone who thinks they know what they are talking about. Love all the new product you are developing and can’t wait to see more.
Tomi Engdahl says:
AUDIOPHILES aren’t always sure they’re audiophiles, like Matt the recording engineer
https://www.youtube.com/watch?v=Hd5Vz2TLcE8
I jumped on the NYC subway to make it out to Rockaway Beach to visit Matt Walsh’s Oceanus studio, I had a great time!
Video comments:
If you’re being interviewed by Steve at your own place, you’re an audiophile already!
“If someone give me a ton of money .. I would get my room treated” – Definitely NOT an audiophile
A friend of mine is a classical composer. My favorite recordings of his work are when there’s just a stereo mic near the front seats of the auditorium – recorded live. No mixing, compression or anything. There’s some audience noise too, which I like.
Tomi Engdahl says:
https://www.nordost.com/valhalla-reference/ethernet-cable.php
Yep really embarrassing marketing. Funny story about timing error
Tomi Engdahl says:
https://audiobacon.net/2019/04/05/sotm-snh-10g-audiophile-ethernet-switch-review/
Tomi Engdahl says:
The thing with digital is, it either works or doesn’t. Even if it’s not the proper cable, the fact you hear something, means it’s only going to be perfect. Or silence. That does not mean that your connection will stay stable.
almost true, there is still some glitchy area between working and not working – visually evident on digital video cables like HDMI and SDI. You can get cables were most things work, but certain scenes mess up because of the specifics of the electrical signal makeup.
Likewise, if you have a poor quality Cat5e cable for a digital stage box, you can get momentary clicks, pops, drops. They might be quite rare, but they are there.
Tomi Engdahl says:
http://www.humblehomemadehifi.com/Cap.html
Tomi Engdahl says:
Tweaking my network audio interface
https://www.youtube.com/watch?v=tPWS3Lk6y1g&t=2s
Although the combination of the SOtM sMS-200 Ultra and Mytek Brooklyn sounds impressively good – or perhaps because it sounds impressively good – I went all the way trying to find the ultimately achievable…..
Viewer comments:
Every Lan isolator (transformer based) in order to work shouldn’t we first mention the basics Hans. I mean both sides should be grounded and also the RJ 45 plugs must have the metal strip also. Who’s has a modem router which has ground ? or a ethernet socket grounded ?
sibilant sometimes or often comes from the DAC solved by using Better quality output opamp eg. discrete transistors packed as DIL pkg, eg Burson opamp. or put a buffer tube in front of the DAC.
Hans, I had similar results wit an AQVOX AQ-SWITCH SE with matching cat7 Ethernet cable. It features “Galvanic isolation with signal transformers 1500 V withstanding voltage”. Have you ever tried one?
Hi Hans,
Thanks for again an enjoyable video.
From own experience I also know the analoge interconnects can introduce or avoid (reduce?) sibilance.
Besides that, some speakers introduce sibilance (Jordan JX92S is sibilant in near field and needs to be listened to off axis).
The last couple of years I am using speakers that were designed to be both time and phase coherent (from Green Mountain Audio).
Sibilance is thereby also greatly reduced.
Great video as always Hans!
Please note not only transformers offer galvanic Isolation, also optocouplers do. Especially in digital circuits due to their specific properties like steep and fast switching, block waves. Thereby reducing time shift. Although when buffering is used that should be a problem for audio, the timing should not be an issue, as timing should be incorporated into the format specifications and not depending on external influences. (I am a theoretical analyst, does it show?)
More practical : A suggestion for using galvanic ethernet Isolation devices is to look at the medical sector, where galvanic Isolation is regulated, certified galvanic Isolation is mandatory and of vital importance to safety of patients.
Could be a lifesaver for over enthusiastic audiophiles too
Being professional, certified equipment it is still not expensive.
Example (hope it’s OK to publish this link, have no affiliation with these guys whatsoever) :
https://www.medicalitshop.nl/37-netwerk-isolatoren
Hi Hans
As usual very informative video
I always wonder many ridicule USB interface as worst thing happening to audio in the name of convenience and no matter what bandaid product’s like Uptone usb regens used to solve USB issues, it cant completely solve it
I wanted to know from you is USB so bad ?
I mean with all the regens and a good usb implementation it can’t compare with a i2s bridge on a pc connected to an i2s input to a dac ?
If you or anyone else has experienced and tried both methods to connect a dac to a pc or a music streamer please do share your experiences
So incredibly interesting. I think sibilance can’t fully be fixed from any equipment. I feel it is at Least 90% music source related. No cables, amps, power supplies etc can fully fix bad recordings.
Tomi Engdahl says:
Sibilance is a figure of speech in which a hissing sound is created within a group of words through the repetition of “s” sounds. … Some people think that other sounds can be used to create sibilance, including “sh,” “th,” “f,” “z,” and “v” sounds.
https://www.litcharts.com/literary-devices-and-terms/sibilance
Tomi Engdahl says:
“And I am getting nervous about DC leaking to my speakers.”
Many direct coupled amplifiers have output relays that connect speaker to amplifier output after some delay from power up and when DC balance is OK. Of DC balance is too far off it will disconnect speakers immediately.
There are also separate protection modules available that can be plugged between amplifier and speaker.
” I can set to 0v which is good. But that can shift slightly at times. But not by mutch.”
A small shift should not worry too much.
“Has then ever been a scenario of failure before?
Is it possible for the DC offset circuit to simply fail, and release all the DC to the speakers blowing them?”
DC control circuits can fail. Is case of fail the DC protection circuit should disconnect speaker immediately. But those can fail also and there are amplifier designs without them.
Those circuits can fail. I have witnessed one such catastrophic failure myself.
“Or is it a lower current which drops if that happens?”
There are slight failures and catastrophic failures.
“As on Tube amps, a Output transformer is an isolated Step Down device, its “in my mind” “more dummy proof” being completely physically isolated like that.”
Output transformers and capacitors block DC. They give some peace of mind but also can easily affect sound quality negatively compared to direct coupled.
“Can anybody comment on Direct Coupled Outputs?”
Direct Coupled is widely used technology on hifi and professional amplifiers.
Tomi Engdahl says:
Do we need audiophile Ethernet switches or is this “audio grade” just marketing bullshit?
PhoenixNET
Audiophile-grade Network Switch
https://innuos.com/phoenixnet/?utm_source=stereonet.co.uk&utm_medium=banner_970x250&utm_campaign=PhoenixNET_Network_Switch_May2021
Typical IT network switches/routers are designed with the sole purpose of taking data from A to B with a noise floor and precision that is “enough” for the rate of transmission. This is fine for data networks but when sensitive components such as DACs and Pre-Amplifiers are involved, it will have an audible impact on sound quality
Tomi Engdahl says:
Phase Linear gear
https://www.youtube.com/watch?v=aNQH9K3soes
Phase Linear was once a revered brand amongst audiophiles. Paul remembers them and their founder, Bob Carver.
Viewer comments:
Phase Linear was truly the “bomb” in its days. Nearly every disco in Denver I DJ’d back in the seventies employed them (other than one that used a Crown), and boy, could they deliver. Also didn’t know that Bob Carver founded the company. Great video and walk down memory lane! Thanks, Paul!
I sense some jealousy from Paul. Whenever Paul brings up Bob Carver he has to make fun of him. He will make fun of him and then superficially give him credit. Pure jealousy. Carver knows his stuff
Bob is a wonderful man! Absolutely brilliant.. The Phase Linear board of directors voted to sell Phase Linear to Pioneer Corp.. Bob left and started Carver Corp..
The transistors that Bob used for his Phase linear amplifiers were the new high-power transistors designed for the high voltages of auto electronic ignitions. Also the “flame linear” issue was partially but not totally solved early on with a modification . A company called White Oak Audio makes a new control board that totally solves the problem.
Damn, forgot about the “flame linear” thing, thanks for that set of memories!
Tomi Engdahl says:
Is there a national sound?
https://www.youtube.com/watch?v=i6rEnYbZpNM
Ever heard of the British Sound? How about the Japanese Sound? Paul clues us in on the various stereotypes for sound reproduction in the home.
Tomi Engdahl says:
Do optical audio cables eliminate noise?
https://www.youtube.com/watch?v=Z9bif7vZsmE
Optical cables have one big advantage: total isolation from their connected source. Does that mean their use is the best digital interconnect in a high-performance system?
Tomi Engdahl says:
Room tour: AudioQuest cables for consistency
https://www.youtube.com/watch?v=5kwXUyqnJNg
use the same audio cables today that I used last year, the year before and the year before that. This video goes a little deeper on the what. The why is obvious: consistency.
https://www.bluejeanscable.com/store/data-cables/index.htm
Tomi Engdahl says:
When to stop upgrading your stereo
https://www.youtube.com/watch?v=7M1YsZW_S0A
Stereo upgrades seem to sometime go on forever. When’s a good time to stop and how would you know?
Viewer comments:
“I’m happy with the sound.” Stop right there, Vlad, before you go down that rabbit hole. Don’t let some stupid mythical ‘rule’ interfere with your enjoyment of the system you already have. You may spend thousands – tens of thousands – and not have the synergy you have right here, right now. Buy more music instead – that’ll give you more pleasure!
Maybe upgrade the speakers one more time to tap the potential of the electronics now untapped, but listening sessions should make sure of that. If successful, it will make Vlad even happier. If not, then the good news is twofold. Vlad is already where he wants to be and it costs $0
Upgrade when you can as long as its not hurting your financial situation. Its not the amount you put in a system, rather the joy and personal satisfaction you get from it. There will always be something better than the $1000 or $100,000 set of speakers.
Tomi Engdahl says:
Layout of Ethernet Isolators
https://www.diyaudio.com/forums/digital-source/371235-layout-ethernet-isolators.html
Since I have noticed a very positive effect on the sound of several end devices through Ethernet isolators directly in front of the end devices when streaming music, I am currently working on their construction and building some myself.
Ethernet magnetics are used for isolation, which are also used for coupling with Ethernet end devices. These usually consist of a transformer with a common mode choke behind it. This reduces noise on the line, which is noticeable in the better sound.
Picture of the DeLock Isolator:
PHY on one side and RJ45 on the other is the normal use case.
But if a transformer is placed in the middle of the cable to filter noise, as is the case with the isolators, then there are RJ45 on both sides.
The question for me is whether the center taps should be terminated with 75 ohms and a condenser on both sides?
For some kinds of conducted RFI/EMI noise it may be necessary to do some experimentation and measurements to find out what works best in the particular circumstances where there is a problem.
The purpose of the 75-ohm resistors and cap connecting transformer center taps to ground kind of looks to me like a way to help dissipate high frequency components of transformer phase imbalances and or common mode coupling through the transformer. The resistors are probably chosen to dampen unwanted transformer output signal imperfections and dissipate their energy as heat in the resistors.
The component values and circuitry are likely particular to the design shown in the schematic.
If you are asking about adding similar circuitry on the primary side of the transformer then the effects of that would have to be evaluated. It might help or it might hurt performance. Modeling and measurements would be advised to help understand the consequences.
However since this is for audio, one could always let one’s ears be the guide. Is the sound the same, better, or worse with a change to the circuit design?
My observation of numerous devices with 100MHz Ethernet connected through an RJ45 jack is that ***all*** of them contain an internal magnetic coupling transformer positioned between the PHY transceiver IC chip and the RJ45 jack.
Some manufacturers of RJ45 jacks offer models where the magnetic coupling transformer is embedded inside the housing of the RJ45 jack itself.
During the 1980’s and 1990’s several CD player manufacturers experimented with internal optical isolation between the CD transport and the DAC/analog output section. However this eventually fell out of favor. My experience was it sometimes caused issues that didn’t occur in non-optically-isolated CD players.
Later high-end disc players (Sony DVP-NS999ES for example) have direct electrical connections between the transport section and the analog section. However the DVP-NS999ES does have ***entirely*** separate power supplies for its digital vs. analog sections. The analog power supply section of the DVP-NS999ES is entirely “linear” and has a 60Hz power transformer. No “switching regulators” are employed in the analog section.
Its not that I think the signal and bits are getting worse by noise.
But the noise effect the process of converting digital data into analog signals.
The aim must be to keep the dac free from noise.
And yes, I trust my ears, which clearly hear a strong improvement from the isolator / transformer.
If you don’t believe this, you should try it yourself.
This is some BS. Every single BASE-T Ethernet interface already has a transformer on both sides on the MDI side of the PHY.
Originally Posted by TomJones View Post
Since I have noticed a very positive effect on the sound of several end devices through Ethernet isolators directly in front of the end devices when streaming music, I am currently working on their construction and building some myself.
It’s weird since there is already an isolation transformer on both sides.
Unless… Is your patch cable the shielded type? These are the ones with a metal shield around the male RJ45 connector. That connects the cable shield to chassis ground at both ends, defeating the isolation.
Is the device 100M ethernet or 1G? Does it switch from 1G to 100M with the isolator on?
yes, the whole thing is really strange and I’m trying to explain it to myself up to date. Before my experience, I was also upset in various forums about the “nonsense” of audiophile switches. Until I tried the isolator and saw that something sound relevant was happening on the Ethernet route. Feel free to google it, there are many reports about it. The DeLock isolator costs only 20 € (a bargain), everyone should order from Amazon and send it back if they don’t like it. to the questions: I use unshielded cable and only the two pairs necessary for 100baseT and that on both sides.
You can get 100Mbps working fine over chicken wire probably. I strongly suggest you perform a blind listening test before you dump any more time and money into something that is hard to imagine. Adding two more transformers when you already have two and you have UTP cable is not going to help.
Hi I have worked for a very long time in a business where ethernet was the most common cabling besides optical fibers. We measured cabling and connections in polluted industrial environments. As I am audio hobby guy since I was a child of course I gained experience for the hobby as well. We measured cabling with very expensive equipment and saw differences between brands, types of cables (UTP, FTP, STP, SFTP…) and even iron cables that were introduced (but very soon these were excluded). Stranded, solid, CAT 5, CAT 5E, CAT 6, CAT 7 etc. etc. All connections were extensively measured and the report was delivered and stored. Of course we sometimes went to the maximum allowed distance, used cables in places where one should don’t lay cabling and got what was to expected.
Despite the quite weak plugs ethernet has evolved and can be very reliable when things are done right according how stuff is defined. If someone starts messing by inserting superfluous parts and doing things by ear I am very curious how this will measure and how it will interact in standard ethernet environments. It all seems the same thing again: people with often quite visible shortcomings in their audio setup will go in great lengths to start solving things that are not a problem.
That having said … I have listened to such guys that now have even audiophile UTP cables… Audio ethernet switches etc. There is a new niche market where people can dump their excess money. As usual looks and sexy brand names are the largest differences besides the extreme prices. I have yet to meet a PCB in such equipment that was not bought from a known network company
The differences I experienced were marginal and certainly not worth the money so I took that as a given. The people that sell them are very enthusiastic though
As I build linear PSU’s for a hobby I tried these out on ethernet switches. To my astonishment I could easily hear the difference… I should not say this and I paid no further attention but I kept the linear PSU’s
Unfortunately, I do not have accurate measuring equipment to prove this.
But I did the test – I’m talking about a 20€ investment and not 4.000€ for some super duper clocks ore snakeoil switches!
Just try it yourself.
For me this has been the sensation that a device of 20€ brings such a sound advantage.
I also don’t claim that the data arrives somehow different in the end device – that’s nonsense.
I try to explain the effect only by the fact that noise, which are irrelevant to the data transmission, have an influence on the signal processing in the DAC – that noise is the enemy of a dac, I think we do not need to discuss.
The transformers have a CMC and clean up the data traffic.
Back to my question:
Anybody have an idea how to handle the center taps?
The point being that there should be no isolator in between as both sides are already equipped with isolators. The device you want to use in between is meant for isolation of possible high voltage surges till even 6 kV. It is NOT meant to filter out noise. In normal situations it could be called a superfluous device.
https://cdn-reichelt.de/documents/datenblatt/E910/DELOCK_62619_DB_EN.pdf
So: just forget about the sound and my confusing setup.
There are LAN isolators for overvoltage protection – these are commercial goods.
These use standard transformers like those used in NICs.
How should the center taps be terminated in this use case?
Your network devices are already isolated adding another isolator is redundant.
If you want total isolation then your solution is wireless or optical fibre.
You don’t need railway standard voltage isolation in your home network.
Since the audio branch has discovered network audio is a growing market there are a lot of commercial goods that will give the buyers an extreme improvement.
Ok I will make an end to the misery. Beware and pay attention… the Ethernet Isolator made by Delock should just be inserted by the way of 2 standard UTP CAT6 cables or the like. I know, it is shocking. There is no need to even think of center taps as it are ready made devices that work. With standard cables. In the normal situation there will be a PHY/isolation transformer at both sides.
You spoke of using them in the middle of the cables which will always be the case with stuff that is designed to be inserted
n such a case network techs always sigh and use “coupler” blocks. It means they made a mistake by using too short cables. They will need to crimp RJ45 connectors themselves which is (sorry) often worse than automated production cables. They won’t be proud and their colleagues will not be happy. Best is to have one uninterrupted cable and then test and measure it. This is why the coupler blocks have a different name amongst them which is somewhat pejorative.
*please note that the overvoltage protection of the Delock Ethernet isolator (that is NOT a filter) only works when you connect the screw to PE. It is not even mentioned in the data sheet which is worrying as the sole purpose is to protect equipment from high voltage surges.
Engineering is a social construct as we all know but anyway:
https://www.eetimes.com/updating-the-bob-smith-termination-technique/#
Did you by any chance try out linear PSU’s to fight noise? If there is a direct source straying out noise close to the audio band (which noise are you fighting BTW?) it is the SMPS in a switch. Worse are the external adapters. VERY thin ice but there seems to be a correlation of sorts between the voltage and the voltage needed for the switch. Not exact engineering (who cares?) but I found the switches that have 5V adapters to be quieter than the ones that have 12V adapters. After all they often use the same low voltages internally like 3.3V, 1.8V etc. Now I stick my neck out for redemption but decoupling and using beads do make a cleaner voltage in such devices just like replacing the SMPS for a good LPS.
If people think LPS are not useful I always say the linear PSU’s are there because they don’t whine as SMPS do. End of discussion
Originally Posted by TomJones View Post
I was also skeptical when I read reports that an isolator would improve the sound, but had to find out that this was true.
The transformer chip not only has a transformer but also an integrated common-mode coil that filters noise. In my opinion, this may have the greatest influence on the sound improvement. It’s not about isolation, it’s about reducing noise.
In the past I did EMC-measurements with LAN xformers as well and all I can say is that the internal CM-chokes with inductances in the ballpark of 500uH were of little help in reducing CM-noise. Interwinding coupling capacity of these xformers is not neglible and contributes to CM-noise coupling. And I talk of CM-noise with frequencies above 10MHz. In other words, irrelevant for audio,
The frequencies are of course not in the audio range, but can have a negative influence on the conversion from D to A.
There are also common mode chokes (CMCs) in these xformers.
Assuming the transformer (incl. CMC) has positive effects, it may be that this is mainly due to the CMCs.
Would it then make sense to use only CMCs instead of an isolator (transformer + CMCs)?
For the frequencies >10Mhz the xformer does not isolate due to its interwinding capacitance. In that case the cmc choke is the only option that makes sense. To check this, you can wind you cable through several ferrite clamps. This is an effectice CM-choke for these frequencies.
Btw I am not convinced that sound is affected at all by some RF-noise. Do you have any measurements showing this noise, distortion or whatever this is?
Problem with this is noise is … noise. A while ago I tried to make the most audible noise that would barely show up on a FFT. A spike at random intervals did the trick, very audible, yet it is not periodic, so it just shows up as a raised noise floor on audio frequency FFT, which looks innocuous. Yet I noticed a… correlation… between the HF noise floor and the sound quality (and also jitter).
The presence of HF noise in the output is not the direct cause of the bad sound.
Rather, it indicates that the layout and decoupling are trash, which means some critical nodes didn’t get the care and love they need, which is the cause of the bad sound.
I’ve re-read my notes about the hifimediy ES9023 DAC. The bad layout had some amusing effects. For example, no ground plane and no shunt reg, therefore the current from the SPDIF optical output LED emitter flowing in the ground trace added a substantial amount of signal-correlated noise (ie, distortion) in the output, which got better by removing the LED. So the presence of the noise indicated a layout problem. Take-home point: shunt regs that make power supply current constant are a good thing. And if you make an optical SPDIF output, use a current-steering driver, so it draws constant current from the supply, and dumps constant current into ground, but it either sends this current through the LED or dumps it to GND on the LED’s GND pin.
Another issue was no ground plane, so the analog reference decoupling capacitor’s ground pin was referenced to a noisy ground, which made the reference noisy. Since the analog output is the product of the analog reference voltage with the DAC sample code value, this does not raise the noise floor when outputting a digital zero. And the usual way of measuring noise floor is with zero output, so this is not measured, and completely ignored. While playing signal though, the signal is multiplied by the analog reference, so you get noise modulation.
Since everyone measures noise floor with zero samples, this problem is usually missed, thus not addressed, thus it sounds bad.
Also, with zero values, the SPDIF output signal is not the same as with actual signal, so the LED issue above would manifest differently.
If you output a constant digital full scale value, or half-scale to make sure nothing clips, then the reference voltage noise is apparent in the output, and it can be easily measured. Then you can check for noise on the analog reference voltage simply by looking at the output, no need for probes, fix the problem if there is one, and then it sounds a lot better.
For example there was this guy with an ES9018 and the FFT showed it had some jitter, so he wasted his time optimizing the clock. I look at the FFT and tell him you have no jitter, you have 100Hz ripple on analog reference (AVCC) so it shows up in the output as a multiplication of two sine waves, f1+f2 and f1-f2, so you get two spikes spaced 100Hz from your test tone on the FFT. He fixed the ripple, and the “jitter” that wasn’t jitter went away.
Last edited by peufeu; 24th April 2021 at 03:38 PM.
Noise on the output is something that can be measured by FFT even when too low level to easily see on a scope. The perceptual result in that case may not be ‘bad sound’ exactly; its perceptual effect might be masking of some low level musical details that should not be masked. In such a case, a listener may not be aware that anything is missing, so the sound may not be perceived as ‘bad.’
Just a summary of my experience with this forum:
I registered here because I thought that technical problems regarding audio could be discussed openly here.
My question related to how to properly design a product that is well established in the audio scene.
Here are just a few examples that an isolator is a common product for audio:
LAN Isolator
NET Isolator – JCAT . next-gen computer audio
Fur Digital-Fans: Website Klangatelier
Neues aus dem HiFi-Studio Wittmann: GISO LAN-Isolator: Kleines Kastchen mit grosser Wirkung
http://www.acoustic-revive.com/engli…_isolator.html
I have not touted anyone the isolators and said that this is a miracle weapon. i just wanted to discuss the correct implementation of this.
Since nobody has given any thought to this and apparently is not open minded enough and has only tried something like this for his “hammer looking for suitable nails” (which I have not criticized in any way), there is no serious discussion here.
Instead, apparently to distract from the lack of knowledge about the matter, only my audio setup, which I did not want to communicate here at all and was not in the focus, is ridiculed.
I hope this is not the general case in this forum.
There are many posts in other forums, that isolators improve sound also in setups 10 times more expensive then mine and with dacs which are beyond doub (but think my RME is also well engineered). Also when the network is completely isolated with fiber converters. I would like to understand why this could happen. I’m sure this has nothing to do with my setup, it’s a general phenomenon. It is hard to understand, without heard the effect.
Basically, I believe you will find conducted and radiated EMI/RFI everywhere. If it sneaks inside a piece of audio equipment, it can be demodulated in semiconductor junctions as noise modulated in with the audio signal. With steady state RF it can produce a DC opamp output offset. However, real world EMI/RFI is not necessarily a steady-state sine wave, so the offset is not necessarily constant. The explanation you are looking for is probably something like: When you have audio going through a transistor while it is demodulating RF (thus shifting its bias point), that effectively can intermodulate the audio to produce with what looks like noise on an FFT (recall that a single diode can be used as a simple modulator).
Next question might be why is it audible? According to ESS they claim to have done unpublished research showing that some humans can hear very low levels of noise modulation, that people can be trained to hear it, and that the ear is exquisitely sensitive to it.
If interested:
https://www.ti.com/lit/an/sboa128a/sboa128a.pdf?ts=1619334845094
https://www.ti.com/lit/an/snoa497b/snoa497b.pdf
Originally Posted by TomJones View Post
Regarding my initial question, I recently came to the conclusion that you should make a Bob Smith termination on both sides of an isolator, since a cable is connected on both sides.
The article JP posted seems pretty good. They recommend a resistor value different from Bob Smith and back that up with believable measurements. So, yeah.
You could measure it, if you have a scope.
But you could also stick a big ferrite core on the cable. That has different common mode impedance characteristics than the ethernet magnetics.
https://www.eetimes.com/updating-the-bob-smith-termination-technique/#
The 66 ohms for CAT6 and 52.3 ohms for CAT5 cable in the article are for standard 4 pairs. So i have to measure it for my setup – puh! Or use standard cable….
But what about CAT7 or CAT8 cable resistance?
What the ability to ground the termination to the GND pins of a wall socket?
The termination resistors are about terminating the pairs relative to each other. That’s what the article you posted explains, than in common mode, we consider each pair to be just one wire, which then forms another transmission line with the neighbor pairs, and that’s what the resistor terminates. Now, I have no idea whether this will make it sound better, but at least there is an explanation, the effect is measurable, and it’s not woo-woo.
Now, as Jean-paul explains, if you want to make a lowpass filter to get rid of HF noise, for example a LC or a RC filter, then you need to connect the bottom of the capacitor to ground. But in the common mode case, there is no ground. And at high frequency, the impedance of the Protection Earth conductor is high enough to make it irrelevant for filtering.
What the IEC filter in your appliances do is short the common mode noise to the chassis. It then becomes “ground”, even if it is not. The important point is the chassis is a big chunk of metal, so it has low impedance, so even if there is common mode noise on it, since everything inside the box is at the same potential, the device inside the box does not experience the noise as a voltage between different parts of its circuit, so it is not bothered.
So what common mode chokes (like the ones I recommended) do is simply add inductive common mode impedance to your cable. With more impedance, less noise current flows. Being inductors, they’re most effective at high frequency.
The isolation transformer also adds common mode impedance, it is almost infinite impedance at DC, but at HF there is quite a bit of interwinding capacitance, so it becomes less effective with increasing frequency. That’s why ethernet magnetics have both a transformer and a choke. The transformer isolates at low frequency, and the choke adds impedance at HF.
That said, ethernet magnetics are really tiny and the common mode chokes are wound on a toroid core, so they still have some interwinding capacitance. A big fat clamp-on ferrite core won’t have this problem. Try to pick one with a material that has high impedance at high frequency, for example this one. Well, okay, it isn’t clamp-on, so you’ll have to crimp a RJ45, but with some digging, you can find.
Note if you use the SPDIF output of the squeezebox, then the isolation, if it is needed, should be implemented with TOSLINK over optical fiber. If you put the boxes 6 feet away from each other and connect via optical fiber, there’s not much doubt about the isolation
I assume that even with the network cable packed with ferrite clamps the network signal is not affected. Just check it out.
There is nothing to loose.
More than this I suspect this will not help you with your audio problem and you are barking at the wrong tree.
Peufeu,
one more question:
If one wraps one pair (TX or RX) multiple turns around the ferrite ring, would the result not be a kind of a common mode choke?
Regards,
Eric
Yes.
Clamping a ferrite core on the cable makes a common mode choke, it’s a one turn inductor/transformer with the cable instead of a wire.
But if you use a core with a larger hole, like a toroid, you can make several turns, although Cat-5 is not exactly the most “bendable” cable… In fact scrunching it to bend it over a toroid to make turns would probably screw up the nice properties of the twisted pairs.
More turns increases both inductance and parasitic capacitance between windings, so you get better (higher) impedance at lower frequency and worse at HF, there is always a tradeoff.
Since Tom already has a toroid common mode choke and a transformer in his ethernet port, I guess the low frequency part is already handled, but these toroid common mode choke in ethernet magnetics have lots of turns on a tiny core, so they’re not that good for parasitic capacitance. So I figured, why not complement it with a ferrite clamp on the cable.
But in order to know, you’d have to bring in the spectrum analyzer to see what sort of noise there is. Also there are tons of ferrite materials that are more or less effective at various frequencies.
As thought… anything changed in the well proven ethernet standard should be measured for effect and proof what it does and what it doesn’t. No serious manufacturer relies on designing a device without measuring its effect.
No friend in the network/datacenter field? These guys have everything to measure and see the patterns.
Tomi Engdahl says:
Updating the Bob Smith Termination Technique
https://www.eetimes.com/updating-the-bob-smith-termination-technique/#
For designers of Ethernet systems, the Bob Smith Termination technique is regarded as an important approach for migrating potential RF emission and susceptibility problems for Ethernet infrastructure. But, what if the technique has flaws?
Unfortunately, there are some flaws with the termination technique patented by Bob Smith IN the 90s. This article points out potential flaws and then shows how a proposed termination technique can solve some of the problems encountered using a Bob Smith termination approach. The article also provides a physical verification method that designers can use to analyze the impact of the proposed termination technique.
The problematic results of improper termination are difficult difficult to measure and verify. They show up as problems with electromagnetic compatibility (EMC certification and worse as intermittent and difficult to identify performance problems in service. Thus, this article will also provide a sound theoretical approach for evaluating the proposed termination scheme.
Problems with Mr. Smith
In a U.S. patent, Robert W. (Bob) Smith described a method to reduce the longitudinal or common mode current on multipair conductor systems where the pairs are interrelated in a uniform manner. He alludes to the fact that the pair to pair relationships of a CAT5 cable form transmission lines in themselves.
Smith asserts incorrectly that such transmission lines exhibit a characteristic impedance of approximately 145 ohms. His description is confusing and misleading because he does not define the configuration in which this is supposedly exhibited. He correctly goes on to say that the cable can support and radiate common-mode signals. Moreover, he states that there is a method to reduce the common mode radiation by matching the common mode impedance of the cable, and then presents a method of terminating the common mode transmission line, that does not in actuality accomplish that goal well. His termination technique does reduce the common mode radiation, but not optimally and not from the correct understanding.
For a CAT5 cable, there are two common modes of interest. The first is the pair-wise common mode and the second is the cable-wise common mode. In the article to follow, we’ll notes will address the pair-wise common mode.
Smith claims that all four resistors should be 75 ohms (Figure 5) . This means that a 75-ohm resistor in all four terminations would match a common mode impedance of 100 ohms for Z1-3
But Smith claims the characteristic impedance of “some” common-mode configuration that he is attempting to match is 145 ohms. Since it’s difficult to understand in the patent the configuration Smith is describing and configurations typically are not anywhere near 145 ohms, it can only be concluded that Smith’s numbers and approach to deriving them are wrong. Additionally, his matching technique, given a common mode characteristic impedance, does not produce a match.
Thus, Smith hasn’t presented a really workable solution to the problem he has recognized. For example, for CAT5 and CAT5E cable an improvement in return loss achieved by replacing the 75 ohm resistors by 52.3 ohm resistors, would be from 15 dB to more than 28 dB, given a variation in common mode impedance of +/-5 ohms. The variation of common mode characteristic impedance is taken into account in the calculation of return loss (Table 2) .
It is clear that for the 100 ohm and 75 ohm resistances there is a reflection, whereas, with 52.3 ohms there is not. The conclusion is that in the vicinity of 52.3 ohms is correct and that Bob Smith’s 75-ohm value is not correct.
As a note, CAT6 cable has a higher common-mode impedance. This is expected due to the significant difference in its construction. It is anticipated that also due to its method of construction that the characteristic impedances will be much more uniform both versus each other and along the length of the cable.
Further Work
Others may further this work by formal characterization of more cable from a number of manufacturers. A stastical and documented mean for the characteristic impedances of interest would be useful to designers. It is necessary to characterize more cable of different types and from different manufacturers. this work is currently under development.
Tomi Engdahl says:
https://pubudeux.com/diy-gigabit-passive-poe-splitter-sharing-data-signal-and-power-on-the-same-wires/
Tomi Engdahl says:
$2,500 Ethernet Switch Effectively Isolates Audiophiles From Cash
https://www.tomshardware.com/news/ethernet-switch-for-audiophiles?utm_content=tomsguide&utm_source=facebook.com&utm_medium=social&utm_campaign=socialflow
Ever wondered if you needed an ethernet switch that has built-in power conditioning for the sake of better audio fidelity? You probably haven’t, but Synergistic Research has. The company developed a wild ethernet switch that is designed to smooth out electric signals inside the switch in order to gain higher audio quality from audio streaming services, but the price point is dubious, to say the least.
The Ethernet Switch UEF costs a substantial $2,595, which will make it appealing to only the most diehard of audiophiles. For comparison, your average, off-the-shelf 5-port GbE unmanaged switch from TP-Link costs less than $20. And a Netgear GS305P v2 will set you back $70. So stepping up to the Ethernet Switch UEF is a big ask.
the switch is constructed from a solid billet of aluminum and uses carbon fiber to eliminate chassis vibrations from making their way into the switch (which the company claims could interfere with the digital signal). There’s even an optional SR Ground Block that serves as a ground for the switch.
Tomi Engdahl says:
Its brilliant, I’m kinda in awe of companies that actually get away with stuff like that.
https://www.synergisticresearch.com/accessories/ethernet-switch-uef/
Tomi Engdahl says:
https://6moons.com/audioreview_articles/innuos4/
Tomi Engdahl says:
“Snake oil […] has come to refer to any product with questionable or unverifiable quality or benefit. By extension, a snake oil salesman is someone who knowingly sells fraudulent goods or who is himself or herself a fraud, quack, charlatan, or the like.” (wiki)
“A charlatan is usually a writer, speaker, preacher, professor, or some other “expert” who tries to conceal his or her lack of skill or knowledge by resorting to pretentious displays (supposedly a leading authority in his field, he turned out to be nothing but a charlatan).” (OED)
https://www.head-fi.org/threads/synergistic-research-hot-device.744295/page-11
Tomi Engdahl says:
https://www.talkclassical.com/42908-audiophile-c-outlets-improvement-5.html
To answer your question, “why not just buy it and return it if it doesn’t work?”… I have better ways of spending my time, and I wouldn’t want to share my credit card number with a company that puts out placebo devices in the hopes of tricking rich people who really don’t understand how audio reproduction works.
DOUBLE BLIND OR IT DOESN’T COUNT.
Tomi Engdahl says:
https://www.synergisticresearch.com/accessories/ethernet-switch-uef/?gclid=Cj0KCQiA5OuNBhCRARIsACgaiqUSOg_AiVmL9c3WZGrY_YEl0HlLQT8APVmYsxM5yzfbOu1tOnM0FucaApHoEALw_wcB
https://www.thefpsreview.com/2021/12/15/synergistic-research-is-selling-a-2000-ethernet-switch-for-audiophiles/
Tomi Engdahl says:
https://www.tomshardware.com/news/ethernet-switch-for-audiophiles
Tomi Engdahl says:
PC Gamer was not so kind in their analysis of this audiophile grade SSD, and I’m inclined to agree with their conclusions. What say you all?
https://www.pcgamer.com/amp/this-audiophile-optimised-ssd-is-designed-to-make-your-audio-sound-better/
Tomi Engdahl says:
audiophile SSD made 100% of snake oil
only works if your computer is connected via the $2500 unmanaged Ethernet switch posted here a few weeks ago. Of course this also assumes you’re using the $500 ethernet patch cables, $1000 IEC cable to power it, and at least $10000 in speaker cables, etc.
Tomi Engdahl says:
https://hackaday.com/2022/02/02/know-audio-a-mess-of-cables/
Tomi Engdahl says:
Layout of Ethernet Isolators
https://www.diyaudio.com/community/threads/layout-of-ethernet-isolators.371235/
Since I have noticed a very positive effect on the sound of several end devices through Ethernet isolators directly in front of the end devices when streaming music, I am currently working on their construction and building some myself.
Ethernet magnetics are used for isolation, which are also used for coupling with Ethernet end devices. These usually consist of a transformer with a common mode choke behind it. This reduces noise on the line, which is noticeable in the better sound.
Picture of the DeLock Isolator
My observation of numerous devices with 100MHz Ethernet connected through an RJ45 jack is that ***all*** of them contain an internal magnetic coupling transformer positioned between the PHY transceiver IC chip and the RJ45 jack.
Some manufacturers of RJ45 jacks offer models where the magnetic coupling transformer is embedded inside the housing of the RJ45 jack itself.
This leads me to ask this question:
What is the value of adding an ***additional*** external magnetic coupling transformer?
When ***total*** electrical isolation is desired it might be better to use “Ethernet-to-fiber” media converter devices. Look up “media converter” on ebay or alibaba to see examples of low-cost commercial devices which do this. These devices typically have one RJ45 jack and one SFP slot. The SFP slot holds a fiber transceiver module appropriate for the desired type of fiber cable (single-mode, multi-mode, etc.) Two such media converter devices may be connected back-to-back with a fiber cable in between them. This provides a totally isolated data path between the two RJ45 jacks.
I was also skeptical when I read reports that an isolator would improve the sound, but had to find out that this was true.
The transformer chip not only has a transformer but also an integrated common-mode coil that filters noise. In my opinion, this may have the greatest influence on the sound improvement. It’s not about isolation, it’s about reducing noise.
In order to let one’s ears be the guide, it has to be a double blind comparison (with levels matched). Otherwise it’s letting one’s ears and sight be the guide.
This is a good point and is especially relevant when adding an external device such as an isolator, filter, or even a specialized “audiophile” cable.
Keep in mind that digital signals are relatively immune from being degraded by noise or other interfering signals.
The place where reducing noise in the desired signal is most important is in the analog section.
During the 1980’s and 1990’s several CD player manufacturers experimented with internal optical isolation between the CD transport and the DAC/analog output section. However this eventually fell out of favor. My experience was it sometimes caused issues that didn’t occur in non-optically-isolated CD players.
Later high-end disc players (Sony DVP-NS999ES for example) have direct electrical connections between the transport section and the analog section. However the DVP-NS999ES does have ***entirely*** separate power supplies for its digital vs. analog sections. The analog power supply section of the DVP-NS999ES is entirely “linear” and has a 60Hz power transformer. No “switching regulators” are employed in the analog section.
Its not that I think the signal and bits are getting worse by noise.
But the noise effect the process of converting digital data into analog signals.
The aim must be to keep the dac free from noise.
And yes, I trust my ears, which clearly hear a strong improvement from the isolator / transformer.
If you don’t believe this, you should try it yourself.
This is some BS. Every single BASE-T Ethernet interface already has a transformer on both sides on the MDI side of the PHY.
Hi I have worked for a very long time in a business where ethernet was the most common cabling besides optical fibers. We measured cabling and connections in polluted industrial environments. As I am audio hobby guy since I was a child of course I gained experience for the hobby as well. We measured cabling with very expensive equipment and saw differences between brands, types of cables (UTP, FTP, STP, SFTP…) and even iron cables that were introduced (but very soon these were excluded). Stranded, solid, CAT 5, CAT 5E, CAT 6, CAT 7 etc. etc. All connections were extensively measured and the report was delivered and stored. Of course we sometimes went to the maximum allowed distance, used cables in places where one should don’t lay cabling and got what was to expected.
Despite the quite weak plugs ethernet has evolved and can be very reliable when things are done right according how stuff is defined. If someone starts messing by inserting superfluous parts and doing things by ear I am very curious how this will measure and how it will interact in standard ethernet environments. It all seems the same thing again: people with often quite visible shortcomings in their audio setup will go in great lengths to start solving things that are not a problem.
That having said … I have listened to such guys that now have even audiophile UTP cables… Audio ethernet switches etc. There is a new niche market where people can dump their excess money. As usual looks and sexy brand names are the largest differences besides the extreme prices. I have yet to meet a PCB in such equipment that was not bought from a known network company
The differences I experienced were marginal and certainly not worth the money so I took that as a given. The people that sell them are very enthusiastic though
As I build linear PSU’s for a hobby I tried these out on ethernet switches. To my astonishment I could easily hear the difference… I should not say this and I paid no further attention but I kept the linear PSU’s
Here you can read a test of the Isolator: Delock 62619: klangsteigernder netzwerkadapter fur 15 Euro (please use google translate)
https://www.lowbeats.de/schnaeppchen-tuning-plus-schutz-netzwerkadapter-delock-62619-mit-galvanischer-trennung/
The point being that there should be no isolator in between as both sides are already equipped with isolators. The device you want to use in between is meant for isolation of possible high voltage surges till even 6 kV. It is NOT meant to filter out noise. In normal situations it could be called a superfluous device.
https://cdn-reichelt.de/documents/datenblatt/E910/DELOCK_62619_DB_EN.pdf
Ok I will make an end to the misery. Beware and pay attention… the Ethernet Isolator made by Delock should just be inserted by the way of 2 standard UTP CAT6 cables or the like. I know, it is shocking. There is no need to even think of center taps as it are ready made devices that work. With standard cables. In the normal situation there will be a PHY/isolation transformer at both sides.
You spoke of using them in the middle of the cables which will always be the case with stuff that is designed to be inserted
In such a case network techs always sigh and use “coupler” blocks. It means they made a mistake by using too short cables. They will need to crimp RJ45 connectors themselves which is (sorry) often worse than automated production cables. They won’t be proud and their colleagues will not be happy. Best is to have one uninterrupted cable and then test and measure it. This is why the coupler blocks have a different name amongst them which is somewhat pejorative.
*please note that the overvoltage protection of the Delock Ethernet isolator (that is NOT a filter) only works when you connect the screw to PE. It is not even mentioned in the data sheet which is worrying as the sole purpose is to protect equipment from high voltage surges.
https://www.delock.de/produkt/62619/pdf.html?sprache=en
Did you by any chance try out linear PSU’s to fight noise? If there is a direct source straying out noise close to the audio band (which noise are you fighting BTW?) it is the SMPS in a switch. Worse are the external adapters. VERY thin ice but there seems to be a correlation of sorts between the voltage and the voltage needed for the switch. Not exact engineering (who cares?) but I found the switches that have 5V adapters to be quieter than the ones that have 12V adapters. After all they often use the same low voltages internally like 3.3V, 1.8V etc. Now I stick my neck out for redemption but decoupling and using beads do make a cleaner voltage in such devices just like replacing the SMPS for a good LPS.
If people think LPS are not useful I always say the linear PSU’s are there because they don’t whine as SMPS do. End of discussion
In the past I did EMC-measurements with LAN xformers as well and all I can say is that the internal CM-chokes with inductances in the ballpark of 500uH were of little help in reducing CM-noise. Interwinding coupling capacity of these xformers is not neglible and contributes to CM-noise coupling. And I talk of CM-noise with frequencies above 10MHz. In other words, irrelevant for audio,
The frequencies are of course not in the audio range, but can have a negative influence on the conversion from D to A.
There are also common mode chokes (CMCs) in these xformers.
Assuming the transformer (incl. CMC) has positive effects, it may be that this is mainly due to the CMCs.
Would it then make sense to use only CMCs instead of an isolator (transformer + CMCs)?
For the frequencies >10Mhz the xformer does not isolate due to its interwinding capacitance. In that case the cmc choke is the only option that makes sense. To check this, you can wind you cable through several ferrite clamps. This is an effectice CM-choke for these frequencies.
Btw I am not convinced that sound is affected at all by some RF-noise. Do you have any measurements showing this noise, distortion or whatever this is?
Problem with this is noise is … noise. A while ago I tried to make the most audible noise that would barely show up on a FFT. A spike at random intervals did the trick, very audible, yet it is not periodic, so it just shows up as a raised noise floor on audio frequency FFT, which looks innocuous. Yet I noticed a… correlation… between the HF noise floor and the sound quality (and also jitter).
Which of these two ES9023 DACs sounds better than the other?
Time domain output of same previous ES9023 DACs, one sounds good, the other does not. I don’t know if it is as simple as saying “HF noise influences sound quality”. That’s probably too simple. It could be something a bit more subtle like: a lot of HF garbage in the output indicates the product was not properly designed, which will probably correlate with bad sound quality.
Back to topic, this is like saying “this DAC is so transparent that it allows to hear a difference between digital interconnects!!!!!!!!!!!!!”
Translation: the DAC has no jitter rejection, so it needs a special snowflake SPDIF cable.
TomJones explained the ethernet side of things in this post but not the audio side of things.
If TomJones is feeding SPDIF from squeezebox into DAC through transformer, and squeezebox is connected to ethernet through transformer, and adding another isolation transformer changes the sound, then… something somewhere is being a special snowflake about noise, probably the DAC.
What is the DAC and how is it connected to the squeezebox?
The transformer is not made by me, i just used transformers like this: H1102FNL Transformer: Ethernet SMD 0-70degC Trans: RX 1: 1,TX 1: 1-1.1dB PULSE: Amazon.de: Beleuchtung
This was the first i built:
https://www.amazon.de/H1102FNL-Transformer-Ethernet-11-1-1dB-PULSE/dp/B01MXGN8OW
ou have something going on with isolators….
I just love the German way of overengineering/overreacting. I was in a training for heavy industrial equipment with German engineers, there were also some African engineers as guests. They blew up a machine by accident (it could have happened to anyone, don’t get me wrong) and the German engineers all were at once very busy meticulously examining the defects from all angles. The African guys sat together. I went to them and asked what was up. They replied that if stuff blows and matters gets complicated the first thing they are used to is sit together and have a laugh about what went wrong, all glad that no one was hurt
After making fun of audiophile switches for a long time and firmly believing that bits are bits, I achieved an absolute increase in sound with the isolators.
What fascinates me about it is that these are totally cheap parts and not some overpriced snake oil stuff.
I have done several Tests.
With standard switch.
With standard switch with LPS.
With 1m patch cords
With 10m patch cords.
With Wireless router/bridge and then patch cord to the streamer.
Direct connection with patch cord to the server.
CAT8 cable, CAT 5 cable.
In all cases the improvement with isolator is audible.
My “mess” setup is a result of my tests. Believe it or not.
Unshielded 2 pair cable sounds best.
The switch is deliberately only a 100mbit 4 cable, so that it does not produce more hf garbage. The switch is IP67 and encapsulated to avoid microphony.
I use silver litz headphone cable, because these are the most resolving i could find.
Drive the Squeezebox with battery because of the sound
And so on…..
It not happened by accident.
Basically, I believe you will find conducted and radiated EMI/RFI everywhere. If it sneaks inside a piece of audio equipment, it can be demodulated in semiconductor junctions as noise modulated in with the audio signal. With steady state RF it can produce a DC opamp output offset. However, real world EMI/RFI is not necessarily a steady-state sine wave, so the offset is not necessarily constant. The explanation you are looking for is probably something like: When you have audio going through a transistor while it is demodulating RF (thus shifting its bias point), that effectively can intermodulate the audio to produce with what looks like noise on an FFT (recall that a single diode can be used as a simple modulator).
Next question might be why is it audible? According to ESS they claim to have done unpublished research showing that some humans can hear very low levels of noise modulation, that people can be trained to hear it, and that the ear is exquisitely sensitive to it.
If interested:
https://www.ti.com/lit/an/sboa128a/sboa128a.pdf?ts=1619334845094
https://www.ti.com/lit/an/snoa497b/snoa497b.pdf
Hi peufeu,
many thanks for your explanations.
So common mode choke without the problem of the transformer with termination will be the way to go.
I will test the ferrite rings you linked.
Should there be a great distance between the ring für RX and TX?
How many turns would you recommend?
There are also common mode chokes available for 100/1000base-t1 (single paire ethernet): https://www.we-online.de/katalog/datasheet/744232222.pdf
Will these have the same effect as the ferrite ring construction? But these are to tiny to solder by hand ;-(
The ferrite ring should be over all cable pairs and you can decide to have a few turns of the complete cable going through the ring in case of heavy assumed RF. The Common mode filter you link to is not specifically for ethernet and ethernet devices already have common mode filters built in. Again, adding superfluous stuff does not make signal integrity any better. Please have a device available that shows you visually what you do to the signals, this is NOT like analog where ears can decide what is better. I am sure it is even the worst approach to improve data transmission. Likely a “by ear” evaluation will lead to wrong decisions and mask issues at either sending or receiving side.
BTW when using analog signals you will have all problems solved. Then you can isolate as well but then with transformers. No RF issues.
Remember network analysers are for RF work and use 50R or 75R impedance. You’ll need a specific analyser for ethernet cable applications.
Ferrite clamps come in all sorts of materials and you will have to decide what frequencies and attenuation is required. Only pass two loops of ethernet cable through the ferrite clamp any more will increase attenuation but the downside is it will narrow the effective frequency range and will result in less than ideal minimum cable radius bends.
As the positive effect of the isolator is often discussed in different forums, i googled a while, if there are any measurements available to understand what happens – but there arent.
It’s audiophile stuff lol. There are never measurements.
I was simply suggesting to slip a ferrite core on the cable and see if it sounds better. Hey, even if it’s placebo, it still sounds better!
Testing for common mode noise is rather complicated btw.
I assume that even with the network cable packed with ferrite clamps the network signal is not affected. Just check it out.
Yes.
Clamping a ferrite core on the cable makes a common mode choke, it’s a one turn inductor/transformer with the cable instead of a wire.
But if you use a core with a larger hole, like a toroid, you can make several turns, although Cat-5 is not exactly the most “bendable” cable… In fact scrunching it to bend it over a toroid to make turns would probably screw up the nice properties of the twisted pairs.
More turns increases both inductance and parasitic capacitance between windings, so you get better (higher) impedance at lower frequency and worse at HF, there is always a tradeoff.
Since Tom already has a toroid common mode choke and a transformer in his ethernet port, I guess the low frequency part is already handled, but these toroid common mode choke in ethernet magnetics have lots of turns on a tiny core, so they’re not that good for parasitic capacitance. So I figured, why not complement it with a ferrite clamp on the cable.
But in order to know, you’d have to bring in the spectrum analyzer to see what sort of noise there is. Also there are tons of ferrite materials that are more or less effective at various frequencies.
I was simply suggesting to slip a ferrite core on the cable and see if it sounds better. Hey, even if it’s placebo, it still sounds better!
Hi I worked in industrial environments with IGBT high power rectifiers/inverters where the clamp on ferrite cores were the solution. This was with “slow” ethernet and a hostile environment with many frequencies and high voltage where odd things occur now and then.
Updating the Bob Smith Termination Technique
https://www.eetimes.com/updating-the-bob-smith-termination-technique/#
https://electronics.stackexchange.com/questions/161436/why-is-bob-smith-termination-for-ethernet-recommended-if-its-wrong
Tomi Engdahl says:
.
This ground breaking paper revolutionized audio circuit design in 1980. It was written by celebrity audio circuit design engineer Walter Jung of Analog Devices. A must read for all serious Audio Amateurs and DIYers who build their own audio circuits. Although this paper is forty years old, its message is still valid today. This paper contains hi math and is difficult to read, follow, and understand for most people. There is also good practical information that can be used in modern audio circuits and is worth enduring the hard read in my opinion.
.
Tap or click the rectangle box below to download and read. …
https://www.facebook.com/groups/DIYAudio/permalink/5489072734491861/