There is also being open-minded and honest enough to change your position when something is conclusively demonstrated to you that turns your previous beliefs on their heads. Take, for example, Naim’s belief that a Unipivot couldn’t possibly work effectively. That stood until one particular R&D Engineer who had come to Naim to work on tuners, presented an idea for a Unipivot that he was convinced would work well. Allowed to make some prototypes, these went on to convince the sceptics both within Naim and beyond. The rest, I guess, is history.
A core ethos of Naim is to build and work from a knowledge base but always be open minded to new ideas and approaches. There is time allotted within the R&D week so engineers can pursue “blue-sky” projects, something that only really works with an open-minded approach.
No not really… that is transport clock jitter… which these days in just about all DACs is decoupled from the digital DAC clock.
We were talking about coupled noise into ground planes, Powerlines and electro magnetic fields… which can interact with sensitive DAC reconstruction electronics including the clock.
One example of this the difference between WAV and FLAC decode that some people can hear the difference between. Assuming decoder is not broken, this difference is caused by the different noise profile caused by the WAV PCM decoding and serialisation electronics with the FLAC decode and serialisation electronics.
The key thing this coupling is product and environment defined.
Is there any research on this so called “coupled noise” or evidence to support their interaction with sensitive DACs, and through the use of a better Ethernet cable and/or switch this is eliminated? And that the difference is clearly audible?
EM is easily measurable - so it’s it’s causing the issues you are claiming then logically the impact of the EM is also measurable.
Absolutely… my point is about denying something which by definition is not being open minded… but then subtly slipping in a change in approach. So yes we would appear to be in agreement and share the same values…
If Naim or anybody states with their latest products and technology they are now able to somehow maximise performance through using previously unused techniques or approaches that is different.
Evolving and learning affects all of us who work in ITC… but denying something and then silently going against that without a stated reason undermines trust… and you can see companies come a cropper when they loose customer trust.
Notice a a noise coupling jig is mentioned… often this can be a coil fed into a receiver.
Electro magnetic relationships and coupling were discovered by Faraday and later used by Marconi to develop radio.
If you are interested in learning the engineering and science of coupling and interference mitigation, an interesting path is obtaining your CEPT radio licence… you may even get question on it in your exam… I did (it was about electromagnetic intermodulation interference coupling affecting a TV.)… This is also part of my professional world now, albeit from a security perspective
I guess it was this open mindedness that got me challenging the defacto Netgear switches back in the day that were often used by home streaming setups, I guess I like to challenge assumed consensus. I discovered an induced coupled birdie causing intermodulation in my NAT03… the FM coax was parallel to an Ethernet lead connecting to the Netgear… I swapped the switch out with a Cisco 2960 that I had spare… the birdies disappeared… for me the rest is history in terms of audio and noise coupling… I undertook many experiments and even shared some of my findings with Naim back in the day (inter frame timing consistency affecting sound characterisation from first gen streamers)
I’m not sure what you describe is accurate when it relates to the article, but i might be misinterpreting it…
This is the test setup:
They use a number of different UTP cables and switches to provide a source signal to a Logitech Squeezebox Transporter streamer/DAC.
On the RCA output of that DAC they measure the amount of noise / jitter / distortion, and how much that deviates for each combination.
Their findings are that all the cable and switch combinations produce (near) identical output results, with only a 0.0001% deviation, which should be impossible to discern for a human being.
They are using this E-MU 0404 calibrated ADC / measurement device to capture the analog output of the DAC:
I still they are referring to transport jitter. The measurements quoted are relevant for that… I will read the article in full later to see if I have missed anything… and will be device and environment specific…
However if listening to a device, if no discernible difference is heard based on differing environments and connections, then great. If a difference is heard but you can’t see it with your measurements, you are measuring the wrong things.
I would like to look at pink noise, and then measure the power density per frequency bin … and compare … you might need to average over much time per measurement… and use quite granular bins.
I am sure there are many similar measures… but that is the one I would like to do first… and focus around very fine bins in the speech frequency range.
I readily admit, I have decoupled my transport from my DAC other than a Naim DC1 SPDIF lead… and I don’t hear the effects of networks, switches, or Ethernet leads in any meaningful way now… yes there can be ultra subtle sonic shifts, but certainly not one having better SQ over another…
The Audio Myths… food for thought thread had an interesting debate and discussion on that… if you haven’t already watch the video.
Ultimately we should be sceptical of our subjective hearing ofcourse, especially when we enter the domain of miniscule changes such as the ones discussed here.
Human hearing is notoriously unreliable, or perhaps a better word is circumstantial. Just a tiny bit of stress, either positive or negative, can completely change what we focus on and how we perceive it. If we can’t measure it objectively, it is statistically much more likely that we are fooling ourselves into hearing something that isn’t there, or are focusing our attention on something different in the music than before.
You are both right If it is heard but not measured, the measurement is not suitable. At the same time it is difficult to be sure it is heard. Statistically relevant blind tests with tens of thousands of participants like in pharmaceutical studies are “rare” in hifi.
On the topic of unreliable hearing and the difficulty of blind testing in audio things: A German TV magazine did a blind test of violins, a few years ago: A Stradivarius, a very expensive modern concert violin, and a basic beginner’s model of good quality. The blind testers were Anne-Sophie Mutter and two other experienced people with orchestra backgrounds.
They could not distinguish the Stradivarius and there was no clear winner. Some preferred the beginner’s model. Conclusion: Either generations of violinists and conductors were deluded, or blind testing these things is more complex than naively expected
Reading the TI article, and let’s just focus on ethernet cable for now - the one clear recommendation is to use shielded Cat5E cables, which I think in today’s day and age everyone is doing that. But you are arguing that even that’s not enough? where is the evidence for that?
Because when reading different forums I find people sharing a real improvement with audiophile switches for all the well known dacs or servers/ dacs , be it dcs, linn, Innuos / chord Dave, Naim, and even the 130 k MSB.
Sorry don’t follow your argument? What are you basing your personal assertion that everyone uses shielded Cat5e these days? Is it based on your personal experience? Where is the evidence? Certainly in my personal and professional experience shielded Cat5e cables are somewhat unusual… and is indeed not part of the Cat5e specification, but is not specifically excluded. Certainly all my Cat5e runs are un shielded, and my Cat6 are.
At least you have one exhibit of evidence (web document) to understand that there are multiple sources of EMI even from an Ethernet cable. Now show me yours…
This is a very good point… measures are not limited to measurements from electrical measuring devices… subconscious bias needs other methods to measure and assess.
I feel this thread and the Audio Myths… food for thought thread have many similarities…
Im surprised you didnt know that Cat 5 and above ethernet cables are now pretty much mainstream, and a key benefit of Cat 5 over Cat 4 is the shielding against EM that it provides. And in any event, the TI article you linked doesn’t say anything about whether EM affects sound quality in the context of a music system - please provide a more relevant source to back up your claim.
of course, I’m still waiting for your documentary evidence to show that a network switch can provide sonic benefits in a music system.
You probably meant Cat5e. Cat5 cables are old and most will have been replaced by now. Typically Cat5e cables are not shielded but some retailers offer it as an option.
Well I’m using cat 6a (inexpensive BJC) throughout my network so there’s a data point for you. And I preferred the BJC over more expensive Audioquest cables that I blind tested multiple times. And the folks at AV Options recommend the ER switch here in the states for those saying Naim don’t recommend boutique switches for their equipment. After hours of testing I’m satisfied with my cisco POE arrangement.
Yep, now that I’ve read that I’m going to throw mine away. Clearly I have been deluded. In other news my car measures no Doppler effect conclusively proving that in fact it cannot move at all and therefore I’m going to throw that away too
While both have the totally expected outcome, my fundamental problem is that for 40 years I have been told by people that this and that can’t possibly make a difference. And I am glad to not have listened to them.
In a wider view, I abhor science deniers and the popular version of the skeptics movement (i.e. denying everything not in the grasp of current science, typically based on very limited unterstanding) by equal measure.
, you can read the Naim and others white papers… and as Naim use TI DACs this is a good paper from TI on how to reduce noise emissions using their PHYTER chipsets. 
If it is heard but not measured, the measurement is not suitable. At the same time it is difficult to be sure it is heard. Statistically relevant blind tests with tens of thousands of participants like in pharmaceutical studies are “rare” in hifi.