Computer Audio Design(CAD) Ethernet Control

We wrote this to try to explain why comparison tests are mostly valid for analogue cables, but are system and environment specific for digital cables:


A comparison of signal and noise transmission in Analogue vs Digital audio.

Effects in analogue transmission are easy to understand.

The signal is transmitted in the same form in which it will be directly converted to sound. Any ‘in-band’ alteration to this signal directly affects the resultant sound in the same way as the alteration to the signal. This means that such alterations may potentially be heard in the same way as the alteration is made – this directness results on listening test giving reasonably consistent results.

An exception to that is out of band signals (such as spurious ultrasonic frequency components, such as from early CD players). These signals affect the way amplifiers behave when amplifying the ‘in-band’ signal. This means that out of band signals will have different effects dependent on the interaction of the signal and the design of the amplifier(s). In the case of analogue transmission this indirect effect is usually smaller than the direct effect.


Effects in digital transmission are more difficult to understand.

The signal is not transmitted in a form that is directly related to the sound produced; rather being transmitted as a set of numbers encoded on an electrical signal. If the signal itself is altered, i.e. the numbers are changed, the system will correct or resend and the signal is restored. However, the numbers are transmitted using an electrical signal, and this signal also carries with it electrical noise, usually mostly at frequencies outside the audio band. This signal can affect the following analogue amplifiers (including the DAC) in a manner similar to out of bound signals in the case of analogue transmission.

Since this electrical signal isn’t the same signal as the sound that will be produced by decoding, the effect of changes to the electrical signal are not directly connected to changes in the sound produced; the effects are due to interaction of the interference caused by the electrical signal affecting the way the DAC and amplifiers behave. As this is not a direct effect on the signal, there is no way to predict how the effects on the sound will change if either the electrical signal or the amplifiers are changed. There are, however, two effects that are likely to be predictable to some degree, provided the reliability of data transmission is maintained:

  1. Reducing the amplitude of the noise on the electrical signal will reduce the unwanted effects.
  2. Reducing the amplitude of the electrical signal will also reduce unwanted effects.

Note that reducing the amplitude of the noise on the electrical signal by analogue filtering will also reduce the sharpness of the edges on which digital data transmission relies for decoding; excessive filtering will reduce noise, but also degrade the quality digital transmission, and this may cause more serious unwanted effects.


Still there’s a kind of consistency in what people saying about ethernet filters impact. Though the magnitude of the effects is different. I haven’t assessed yet for myself but plan to do at some point.

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Thanks for sharing this. I’m going to bookmark it.

The EE1 has worked out very well for me. Very surprised at how much better it sounds when replacing the free C-Stream 1m cable with a Shawline 1m cable.

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I can confirm it fits with the Power line:

Interesting also that in a short manual for the product they use Naim streamer to illustrate:


Wow!! Thanks @Phystech clearly it fits just fine. Of course I can’t wait to hear your impressions of the CAD Ethernet Control.

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Well, I’m at the stage of the network development where I believe there’re no silver bullets to do it all in one shot. I would not be able to write a review of the filter as it does just one simple thing for me - increase of resolution/subtle nuance. Not night and day but valuable enough. What I did in particular for the system was: took a Tellurium Black Diamond interconnect at a good price, then traded my Super Lumina and used that cash to finance ethernet filter. While I believe SL is better vs Tellurium (but I still have rca somewhat better than both), combination of CAD and Black Diamond is definitely a step forward for the system. On top of that filter has one attribute that may be considered quite valuable - when it is already in the system, there’s no point to unplug it. It doesn’t have its own voicing at all as far as I can notice now. So no changes to the character of the presentation. It’s not like power supplies or routers or cables.

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No worries. I’ve been there plenty of times. Hard to distinguish changes when multiple things have changed! Lots of items need an adjustment period as well.
Increased resolution is what I’m looking for. “there’s no point to unplug it.” this is a good sign

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I will follow your updates with interest as these devices can be interesting when they work in your system, especially if there’s no change to the voicing. That’s the one area that’s put me off a bit. Changing SMPS’s for LPS’s has definitely affected the balance of my system, often pushing the bass a bit too much.

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There’s a review of the Cad in Ear Net.
I realised it costs 1250 GBP. Very expensive I feel. Quite the cost of a very good switch.

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I managed to get one of these little devices on loan from a dealer not too far from me.

It’s been in the system for over a week now but the manual does recommend around 150 hours burn-in. So, in the context of my system these are my thoughts…

Initially it sounds quite impressive. There is definitely a noticeable drop in the noise floor with everything sounding much darker, smoother and calmer. There seems to be a gain in weight to the midrange and lower end, almost like another octave has been added. However, after a while I started to notice a loss of high frequency detail, which for me isn’t so good. I found it became rather annoying, like something was sitting on the dynamics. The trouble with this for me is that it robs the music of that ‘liveness’ I crave. After a while I found it sounded like the signal was just being over-processed and smoothed too much. Even that extra bass weight became a little false. On some studio and electronic tracks this smoothness was a benefit but on live tracks it was a definite disadvantage and not really the direction I want my system to go.

How this might all translate to a non-Naim system is anyone’s guess and, as with all things streaming related, you are probably going to have to try it to find out but for me it’s all a step too far, so it will be going back to the dealer before the end of the week.


This is part of the fun of our hobby, trying out different components to see if they make an improvement.



Thanks for the feedback. Much appreciated. I do wonder if more burn-in will help.

Interesting. What you described looks like a usual linear power supply for me. You may be forced to balance between more depth/weight of lps and better pace/timing of smps. All my ps are smps currently after a long time with lps and my filter experience is somewhat different, I don’t feel smother/darker sound.

Funny you should say that as I’ve had seven linear power supplies on trial and have settled on the standard Chord SMPS for that very reason. I like the speed and HF definition the SMPS gives. The LPS’s just sound darker, calmer and less well timed, so it seems we are looking for similar traits.

I tried one of the EE1’s a few weeks ago and couldn’t notice any discernible difference. However, one of the Chord ground arrays on my router gave a lovely little tweak to bass definition and realism with no real downside. I was hoping the CAD was going to give more of the same but it just over-cooked everything. The dealer showed me inside the CAD and it certainly contained a lot of electronics. There’s nothing simple or straight forward inside.


It could do. Trouble is the dealer needs it back so I’ve only had a week with it. Although I tend to think it was all a bit too much for burn in to correct but I could be wrong. The Chord ground array I’ve been playing with took forever to come on song but sounds really good now.

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One other thing worth mentioning is that I’m currently using Catsnake as the final Ethernet connection into my ND. I tried a Chord C-Stream and ended up slightly preferring it to Catsnake, as it lightened the bass a bit and put a bit more zing into the high frequencies. Without the CAD Catsnake, for me, is much better than C-Stream, so there may well be some cable combinations that make the CAD work better. I would imagine that Vodka would be a good fit with the CAD sound? Trouble is I don’t have enough time or money to play around with all the possible combinations!


Network is hard, I agree. I’m running Network Acoustics ENO cable, natural choice would be to put Muon pro as the last thing before the streamer but it’s even more expensive.

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I guess I’m getting closer to crack this audio case. I haven’t noticed significantly fluctuating burn-in period, in the manual they’re saying about 150h. However what is interesting is that you can enter a singularity point after that. When the sound improves each time you plug it in or unplug :slight_smile:. Just imagine how it becomes possible to pump the system to the stratosphere :joy:. Seriously, the overall impact is not so big, I would say it’s comparable to a cable with discount. It is less than 1k+ interconnect, more than 1 Power line but less than 2.

However. All that is not relevant as using the filter as a last step before the streamer (as shown above) is a completely wrong way of doing it in my setup. I assumed it from the beginning as putting unscreened electronics near the Power line looks like a compromised idea. In fact ‘clean side’ (it includes last bridged router, its power supply and cable) could not accept it finally. And when I put it to the beginning of the chain… whooa, here we go, baby :slight_smile:. All that reported easy-flowing-3d-analogueness becomes apparent. My assessment of the impact here is bigger than a good 2k speaker cable I tested recently and bigger than 2k power transformer I’m using in the beginning of the chain.

What is a bit crazy and makes me laugh is that the device works even if you just plug it to the main router, without further routing to the audio routers. Maybe not to the max though.


Once again it goes to show just how quirky this game is. I should have been a bit smarter and tried it in different locations but thought the idea of getting it as close to the streamer as possible seemed pretty logical. On the up-side you may have read that I’ve got hold of some Shunyata Sigma ethernet cable, which seems to be doing the same thing and creating a beautiful three dimensional render of any concert or venue I want to go to. I spent last ‘Night at the Opera’ with Freddie Mercury. I’m pretty sure I was sitting in row 10, seat 36! What a night!

When you start to hear digital music without any (maybe less) digital side-effects it really does become the analogue equivalent. Trouble is, until you hear the lack of noise, you have no reference point. I reckon my reference point has been moved at least a couple of times in the last year!