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CAD grounding box, eliminating 'noise'

Thomas savage

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#41
This type of tweak is perfectly suited for doing AB testing on - trivially easy to have in circuit, and removed - so should be easy to verify its effectiveness, for a particular listener.
I'm not interested in that kind of subjective anecdotal information. It's great for individuals on their own in their own world, but totally useless in terms of a point of data to discuss here.
 

Thomas savage

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#42
Thomas, I think you should report him to the home office so that they deport him back to US! We will then teach him the errors of his ways. :)
What happened to just renditioning folks, you guys used to love doing that:D
 

amirm

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#44
If they are not beyond science ( I have a strong feeling they are not) how would we go about measuring the effectiveness of this device?
If by that you mean the sound we hear, that is of course trivial to measure. Simple measure the output of the DAC with and without this device.
 

Thomas savage

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#45
If by that you mean the sound we hear, that is of course trivial to measure. Simple measure the output of the DAC with and without this device.
No, forgetting the sound we hear.. sticking to the claimed removal of noise way outside the audible frequency range.

There's no point in worrying about if something is audible until you know it's fulfilling it's designed purpose , this is where it gets confusing. Like with speakers, cabinet diffraction.. you can prove a approach minimises diffraction, that's a goal and your design can be objectively tested to help one ascertain if your doing things right... of course this then can be teared apart by folks arguing whether cabinet diffraction is audible, this then becomes a nightmare for audiophiles and very confusing. That's one of the reasons ignorance prospers.

So these CAD folk must test the effectiveness of their device in order to design it, it would be nice to challenge them to prove the device 'works' as its intended . Leaving the argument Of audibility for another day.

We live in a world where a speaker company can put a protective cap on a tweeter and get inundated with guys saying they hear more this or that.. buying audio gear can become like a drug addiction, you enable yourself by creating all sorts of fantasies and likewise all sorts of protection arguments that keep those fantasies 'real' / safe.

I want to avoid as much of the shite as possible, so does this CAD device remove any noise? How do we measure this ( some suggestions already, thanks) and why can't we challenge CAD to provide evidence to show this device works.

The argument of whether it's audible will never be won, no point wasting energy on it and frankly it turns people off.. if this device does nothing, removes no noise from any part of the circuit then we don't need to have the ' is it audible ' argument :)
 

Speedskater

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#46
The first three pages of the paper were reasonable, then on page four the train falls off the track. When they start treating ground or earth as a destination rather than a common reference point, they have left the real world.

You can't send bad electricity to a magic box or to Planet Earth and expect it to disappear.
 

RayDunzl

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#47
Here's a somewhat related discussion from someone who seems to have a clue:

https://interferencetechnology.com/...-ground-has-no-effect-on-emi-explain-further/

Cherry-picked quote to get you all excited:

"Given that all currents flow in closed loops, there can never be any such thing as a “noise sink”, so the common idea that noise can be “shunted away into the safety ground” is just plain wrong and always has been."
 

RayDunzl

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#48
Noise...

Since we've all seen DAC measurements at -130 to -160dB for "noise floors"...

And maybe I can safely assume that these weren't taken in an anechoic RF dead room...

Where exactly is this pervasive problem that we need to eliminate?

Random image, in this case from Archimago:

 

Speedskater

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#49
Here's a somewhat related discussion from someone who seems to have a clue:
https://interferencetechnology.com/...-ground-has-no-effect-on-emi-explain-further/
Cherry-picked quote to get you all excited:
"Given that all currents flow in closed loops, there can never be any such thing as a “noise sink”, so the common idea that noise can be “shunted away into the safety ground” is just plain wrong and always has been."
Many engineering books and papers on the subject say exactly the same thing. Yet there is a common misunderstanding in many areas of electricity (it's not just audiophiles) that you can shunt noise currents to ground. Yet Planet Earth is not a sink or sump for these currents.

Back in the real world, noise, interference, leakage, ground and lost Neutral currents all want to get back to their voltage source. And just what is their voltage source? In most cases it's the Hot terminals of the power company's transformer down the street. So these currents want to get back to the transformer's Neutral terminal. The Safety Ground/Protective Earth is connected to that terminal, so the currents are happy to take that path back to the transformer. But in doing so, our hi-fi's chassis's are also involved in the noise problem.
 

fas42

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#51
What may be missing in the puzzle is self capacitance - any body forms a capacitor with respect to everything else, except the value of this property is extremely tiny. But take a metal body with large surface area, and then this starts to be become significant - as an example of where this is taken extremely seriously, metal rods used to absorb lightning strikes can be analysed very precisely as to how a transient surge of electrical energy behaves, which varies greatly with how the rod ends are shaped.

So, these boxes may be forming a snubbing connection to the air around and within them, for very high frequencies.
 

Blumlein 88

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#52
Between the 1960's and around 2000 many cars were sold with spoilers. Especially the premium high performance optioned cars. People saw similar looking devices on real race cars and everyone knew they were a good thing. Looked cool besides. 95% of those spoilers had one functional result in common. They slightly increased aero drag. They did not produce any downforce even at the top speeds of the cars. They did not enhance high speed stability. They did one thing which is increase drag slightly. They did two other things. They looked cool to owners, and generated income for car companies. Collectively the public spent at least one billion dollars or more on these devices to slightly increase drag on their cars. So the design methodology didn't involve wind tunnels or engineers calculating aero results. It consisted of body designers making cool looking spoilers and maybe engineers confirming they didn't do anything too terrible to cross wind stability. There were a few exceptions where the spoiler did something positive, but not many. So the concept in general is okay. Same goes for air scoops or intakes many of which were fake and didn't send air anywhere anyway.

Now I notice CAD offers two versions of their USB cables. One with the +/- 5 volt wires and one without. A certain class of audiophile already 'knows' because everyone knows that USB 5 volt lines are noisy so getting rid of them and connecting an external speciality LPS is going to reduce noise and improve sound quality. Even though I have yet to see measurements to that effect. So did CAD confirm this really happens? Did they even determine the optimum way not to have 5 volts lines in their cable? Or did they just realize a certain segment of customers are pre-sold on the idea and make what the customer will happily buy?

Now there are materials which will absorb high frequencies being talked about.
http://www.masttechnologies.com/rf-absorbers/

They have genuine uses to absorb or deflect noise even in our computers. Page 12 of this PDF has some basic measures of their effectiveness.
https://media.digikey.com/pdf/Data Sheets/Laird Technologies/EMI_MicroAbsorb_Cat.pdf

Here is a page with several guidelines for using the various products from this company (which is not the only company selling such)
https://www.lairdtech.com/PRODUCT-CATEGORIES/RFMICROWAVE-ABSORBERS-DIELECTRICS

Did CAD measure such things on the grounds and chassis of common gear? Did they then design this box to reduce the problem? Did they measure the improvement and correlate it with sound quality? If they have a separate box with many layers of this kind of material next to a copper sheet which connects to ground does this follow the guidelines for use by the makers of this material?

Or did they notice the success of Entreq and similar devices and realize throwing some of this material in a box that audiophiles would accept the idea naively that connecting ground to the right kind of box results in improvements? Then make such a box and 'empircally' thru listening tests determined it really did work. So now it is for sale.


Here is another PDF. Seems to me we might line our listening rooms with this stuff which could be made to both do acoustic absorbtion and diffusion as well as absorbing stray amounts of high frequency waves. So maybe that is another way to think of this CAD product. Would you buy the idea I make a small 1 square foot box that could absorb all audio frequencies and by leaving one side open I 'drain' away room noise. Sure there is some small real effect, but I could hardly dramatically reduce in room noise with such an approach.
https://product.tdk.com/info/en/catalog/datasheets/e9e_bdj_003.pdf


Might want to read this wikipedia page too:
https://en.wikipedia.org/wiki/Radiation-absorbent_material

And I am making assumptions about what might be in the box. I don't know. It is one remotely plausible way I might make such a goofy product. Too often I have seen products that don't even attempt to be plausible. Just famous designers, empirical tests and try it this stuff really works.
 
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amirm

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#53
No, forgetting the sound we hear.. sticking to the claimed removal of noise way outside the audible frequency range.
Well, there is a problem here. Take this fish scale:



You hold the one end and put the hook into the fish, lift the whole thing and measure the weight. It works on the principle of the top of the spring being stationary and bottom connected to the weight.

Now, what if I asked you to measure the weight using that but that you can only use the hook end. Will you be able to measure the weight? Answer is no of course.

Same problem here. These devices have only one terminal. Measurement devices have two. Where do you connect the other wire in the instrument? Dangle it in the air? Some other earth reference? If so, why?

This is the same issue I had with analyzing Entreq. There is only one example of a one-wire device and that is an antenna. But the moment we go there analyzing such a device as an antenna, then the whole argument is lost as an antenna will pick up noise, not suppress it.

This is why I measure the output of the DAC. The DAC has two wires and we can measure what comes out of it electrically with and without the "grounding" device.
 

Blumlein 88

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#54
Well, there is a problem here. Take this fish scale:



You hold the one end and put the hook into the fish, lift the whole thing and measure the weight. It works on the principle of the top of the spring being stationary and bottom connected to the weight.

Now, what if I asked you to measure the weight using that but that you can only use the hook end. Will you be able to measure the weight? Answer is no of course.

Same problem here. These devices have only one terminal. Measurement devices have two. Where do you connect the other wire in the instrument? Dangle it in the air? Some other earth reference? If so, why?

This is the same issue I had with analyzing Entreq. There is only one example of a one-wire device and that is an antenna. But the moment we go there analyzing such a device as an antenna, then the whole argument is lost as an antenna will pick up noise, not suppress it.

This is why I measure the output of the DAC. The DAC has two wires and we can measure what comes out of it electrically with and without the "grounding" device.
Oh this is easily explained. The sound of one terminal clapping.
 

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#55
What may be missing in the puzzle is self capacitance - any body forms a capacitor with respect to everything else, except the value of this property is extremely tiny. But take a metal body with large surface area, and then this starts to be become significant - as an example of where this is taken extremely seriously, metal rods used to absorb lightning strikes can be analysed very precisely as to how a transient surge of electrical energy behaves, which varies greatly with how the rod ends are shaped.
So, these boxes may be forming a snubbing connection to the air around and within them, for very high frequencies.
It's not a puzzle, it's just nonsense! And self capacitance in this situation is less than trivial. Typical self capacitance of a human body to Planet Earth is about 100 to 200 pF. At these frequencies, impedances and noise currents, that's nothing.
 

Blumlein 88

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#56
How about the green alternative.

I have a couple Ubiquity Nanostations. 2.4 ghz wifi devices. I have made solid connections between a pair at over 1 mile. Supposedly they can do this at nearly 3 miles. This is unobstructed line of sight however.

Use them over a dense forest with lots of undergrowth and getting beyond 500 feet gets iffy. And fir trees like spruce.....God's own little 2.4 ghz absorber. Absorbs even better at 5 ghz.

So here is my suggestion. Get a couple of the largest spruce trees that will fit in your listening room in a big pot. Line the pot with a copper grid before putting tree and soil in them. Mount all your gear in the tree, and connect the grid in the soil to the ground of all your gear. True earth ground. The trees will truly absorb high frequencies from the outside world, and those produced by your computers and such. Also will absorb some acoustic sound in the room. Connecting the earth grounded copper grid will make you an audiophool. Mission accomplished. I can guarantee and even measure that the system will sound different with vs without the ghz absorbing spruce trees in the listening room. That makes it science.
 

tomelex

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#57
So, even if there were some 700k to gigahertz noise charges riding around on your "ground", and these can dissipate those charges some, still, ONLY if its audible is it of any value. Can signals on ground interact with your pre amp circuits, yes, if they are say two transistor stages, each one connected to chassis ground, and your poorly designed SOTA device is using chassis ground for a return circuit, well, yes, it is in series with your signal then, but the only possible effect is demodulation by your base emitter junction and then, is there enough there to even hear, and there will be SOME there no matter, but if you can not hear it, it does not EXIST...........oh my oh my, I like that, let me say it again, to me, if your senses can not discern it, it matters not one jot.
 

tomelex

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#58
Well, there is a problem here. Take this fish scale:



You hold the one end and put the hook into the fish, lift the whole thing and measure the weight. It works on the principle of the top of the spring being stationary and bottom connected to the weight.

Now, what if I asked you to measure the weight using that but that you can only use the hook end. Will you be able to measure the weight? Answer is no of course.

Same problem here. These devices have only one terminal. Measurement devices have two. Where do you connect the other wire in the instrument? Dangle it in the air? Some other earth reference? If so, why?

This is the same issue I had with analyzing Entreq. There is only one example of a one-wire device and that is an antenna. But the moment we go there analyzing such a device as an antenna, then the whole argument is lost as an antenna will pick up noise, not suppress it.

This is why I measure the output of the DAC. The DAC has two wires and we can measure what comes out of it electrically with and without the "grounding" device.

My dear King, do you not believe in the alternate universe theory or the many worlds theories, why, over in them, going by the name of KING RIMA is the opposite pole of your springy thingy measurement device, I know, I have been there, and no, he is not as benelovent a KING as you be!
 

tomelex

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#59
Tom, again note that I'm not talking static, unchanging noise - this is interference modulating the signal, a dynamic process - when there is no signal there will be no audible degradation, or noise, heard over the speaker.

Frank, how the hell do cartridges putting out less than one millivolt ever get heard by us without being awash in noise.....dude, noise modulation begs that as the gain increases the noise increases and rides up and down with your signal, well, so what if that actually happened, you cant hear it, it will not even move your speaker cone, it will be burned up in your damn crossover. Get some facts and not just "belief" Find and show this noise modulation audibility you keep jabbering on about Sir. Edumucate us cretins on this horrible audible issue, if you can. Listen to her in the song, she asks if you can...

 

fas42

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#60
At these frequencies, impedances and noise currents, that's nothing.
Nothing? As in meaning a low value? - at 100 MHz, in the middle of the range where this device is aiming at, 100pF is about 16R reactance - that's a nice low impedance conduction path to the "earth".
 

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