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Post by macca on Feb 23, 2022 13:47:47 GMT
I was a bit surprised to see in the 'cable dressing' thread that someone reckoned that there was no way to measure this. Maybe there was some confusion as to what was being talked about, I don't know. But anyway here's an example of it being measured. Scenario is an unbalanced interconnect being wrapped around a power supply brick to try to simulate a worst case scenario. First graph is cable well away from the power supply, second is with the cable wrapped around it.   As you can see there is a difference but it is very small, about 2dB additional noise and distortion in the signal. To test audibility would require controlled listening tests of course, this is just to demonstrate that it is trivially easy to measure this effect. |
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optical
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Post by optical on Feb 23, 2022 13:56:04 GMT
I was a bit surprised to see in the 'cable dressing' thread that someone reckoned that there was no way to measure this. Maybe there was some confusion as to what was being talked about, I don't know. But anyway here's an example of it being measured. Scenario is an unbalanced interconnect being wrapped around a power supply brick to try to simulate a worst case scenario. First graph is cable well away from the power supply, second is with the cable wrapped around it. As you can see there is a difference but it is very small, about 2dB additional noise and distortion in the signal. To test audibility would require controlled listening tests of course, this is just to demonstrate that it is trivially easy to measure this effect. Well found Martin, from this example it could be the case that with a few more of these instances of 'noise/distortion', it could well add up into a very audible change. Yes it's an extreme example, being wound round the mains, but imagine a few power sources/wires running in parallel with un-shielded cables and them themselves perhaps being un-shielded. Effect could well add up. |
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Post by macca on Feb 23, 2022 14:02:07 GMT
I suspect that the effect will vary depending on the composition of the signal cable. Some might pick up a lot more. Yes, it will be cumulative.
Balanced cables were also tested, there was no difference at all with them.
Personally I try to keep as much distance as possible from power and signal cables as I don't use balanced. I also don't leave unused cables lying about near those in use. This is probably paranoia but it costs nothing.
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Post by misterc on Feb 23, 2022 14:04:58 GMT
This is just part of the excerise, I personally would look at three ways of measuring this, conducted noise down the wire via a signal analyser this is FFT (frequency response)as shown above
NextI would I would a very accurate RF current probe to look at the return pathway noise. Followed up by an RF closed loop probe to run along length of the cable again with a real time analyser.
Also you can check for immunity of RF ingress of the reciever again using an RF near field probe. I would also go further than the 100K shown BW as well up to 30Mhz.
This is nothing new at all, it is used daily when checking for signal integrity on ANY HSSDT, the fun starts when you get to board level lol
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Post by macca on Feb 23, 2022 14:09:41 GMT
Was not saying it was anything new, posted this as it was claimed that it was impossible to measure it. At least I think that was the claim.
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Post by Bigman80 on Feb 23, 2022 14:24:08 GMT
Was not saying it was anything new, posted this as it was claimed that it was impossible to measure it. At least I think that was the claim. i think it was aimed more at the fact you believed in cable dressing....which you are right to do as it is a thing. As the measurement demonstrate. Away from that, i would love to know how effective shielding is. Mains cables in particular! evidence as to whay shielded cables should be used? |
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Post by macca on Feb 23, 2022 14:46:15 GMT
Was not saying it was anything new, posted this as it was claimed that it was impossible to measure it. At least I think that was the claim. i think it was aimed more at the fact you believed in cable dressing....which you are right to do as it is a thing. As the measurement demonstrate. Away from that, i would love to know how effective shielding is. Mains cables in particular! evidence as to whay shielded cables should be used? Nope, the direct quote is 'There is no evidence so far, that indicates a measurement is possible' Audibility is an entirely different issue. I suspect it can be audible. I may be wrong about that, but the assertion that we can't measure the effect is clearly incorrect. |
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Post by Bigman80 on Feb 23, 2022 15:21:32 GMT
i think it was aimed more at the fact you believed in cable dressing....which you are right to do as it is a thing. As the measurement demonstrate. Away from that, i would love to know how effective shielding is. Mains cables in particular! evidence as to whay shielded cables should be used? Nope, the direct quote is 'There is no evidence so far, that indicates a measurement is possible' Audibility is an entirely different issue. I suspect it can be audible. I may be wrong about that, but the assertion that we can't measure the effect is clearly incorrect. Ah, yes...you are correct. I stand corrected lol |
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Post by karma67 on Feb 23, 2022 15:31:25 GMT
Nope, the direct quote is 'There is no evidence so far, that indicates a measurement is possible' Audibility is an entirely different issue. I suspect it can be audible. I may be wrong about that, but the assertion that we can't measure the effect is clearly incorrect. Ah, yes...you are correct. I stand corrected lol said the man in the orthopaedic shoes  |
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Post by Bigman80 on Feb 23, 2022 15:32:38 GMT
Ah, yes...you are correct. I stand corrected lol said the man in the orthopaedic shoes Ha! |
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Post by stryder5 on Feb 23, 2022 16:51:25 GMT
I don’t know what a “supply brick” is other than an inline transformer ?
An image from the test showing the method used might help enlighten me?
Oh, I do wear orthopaedic shoes.
Gary
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Post by stryder5 on Feb 23, 2022 17:37:10 GMT
I was a bit surprised to see in the 'cable dressing' thread that someone reckoned that there was no way to measure this. Maybe there was some confusion as to what was being talked about, I don't know. But anyway here's an example of it being measured. Scenario is an unbalanced interconnect being wrapped around a power supply brick to try to simulate a worst case scenario. First graph is cable well away from the power supply, second is with the cable wrapped around it. As you can see there is a difference but it is very small, about 2dB additional noise and distortion in the signal. To test audibility would require controlled listening tests of course, this is just to demonstrate that it is trivially easy to measure this effect. Well found Martin, from this example it could be the case that with a few more of these instances of 'noise/distortion', it could well add up into a very audible change. Yes it's an extreme example, being wound round the mains, but imagine a few power sources/wires running in parallel with un-shielded cables and them themselves perhaps being un-shielded. Effect could well add up. Yes, well found, may yet be totally irrelevant though. Gary |
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Post by stryder5 on Feb 23, 2022 18:46:28 GMT
Was not saying it was anything new, posted this as it was claimed that it was impossible to measure it. At least I think that was the claim. i think it was aimed more at the fact you believed in cable dressing....which you are right to do as it is a thing. As the measurement demonstrate. Away from that, i would love to know how effective shielding is. Mains cables in particular! evidence as to whay shielded cables should be used? I would like to see any measurements done in a controlled environment, where no other extraneous sources could influence the result. Faraday cage? I’m not dogmatic in my opinions, just that other opinions have been expressed that if you can hear any change it must be measurable, If measurable is it in the audio spectrum? Gary |
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Post by macca on Feb 23, 2022 19:05:26 GMT
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Post by stryder5 on Feb 23, 2022 19:38:40 GMT
I believe that’s a Hewlett Packard transformer mains to 19.5volts 65w. Gary |
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Post by stryder5 on Feb 24, 2022 9:41:39 GMT
I was a bit surprised to see in the 'cable dressing' thread that someone reckoned that there was no way to measure this. Maybe there was some confusion as to what was being talked about, I don't know. But anyway here's an example of it being measured. Scenario is an unbalanced interconnect being wrapped around a power supply brick to try to simulate a worst case scenario. First graph is cable well away from the power supply, second is with the cable wrapped around it. As you can see there is a difference but it is very small, about 2dB additional noise and distortion in the signal. To test audibility would require controlled listening tests of course, this is just to demonstrate that it is trivially easy to measure this effect. It’s really easy and trivial to find something totally unrelated! Gary |
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Post by macca on Feb 24, 2022 10:19:34 GMT
You'll have to do better than that if you want to back up your claim that any effect is 'unmeasurable'.
I really don't understand where you are coming from with that statement so a comprehensive explanations would be appreciated.
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Post by stryder5 on Feb 24, 2022 10:54:50 GMT
You'll have to do better than that if you want to back up your claim that any effect is 'unmeasurable'. I really don't understand where you are coming from with that statement so a comprehensive explanations would be appreciated. It’s easy, your post is irrelevant as it describes effect of transformer on signal cables. i think I actually commented that you said you could hear differences when power cable was near signal cable, which I don’t disagree with. However your opinion has, for some time been, if you can hear a difference you can measure it. Your response to proving you can measure this effect was to publish the above, which is measuring the effect of a transformer on signal cables, not the same. The test was in no way in controlled conditions. So irrelevant! Gary |
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Post by optical on Feb 24, 2022 11:21:16 GMT
But the example does provide some evidence as to the potential for mains/power induced noise/distortion from a power cable (or transformer) to a signal cable so I'd say it's a fairly good start, if not meeting your desired criteria?
Also in a "controlled environment" as you describe, you wouldn't be measuring the cumulative effects of other airborne interference which could be measured and audibly affecting the cables in our systems so I would say it may not serve to provide any useful information in relation to real world systems and listening environments.
Granted that's not what you have requested as to evidence thereof but I think it's more useful measuring things in their natural environment (IE with routers/appliances dotted around with surges/spikes and all pitfalls they bring).
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Post by macca on Feb 24, 2022 11:25:05 GMT
Not at all what I said.
Firstly with regard to cable dressing I said 'Even I think that makes a difference'. Key word there is 'think'. I am happy to be disabused of the notion since I am aware of the frailties of human perception.
'If you can hear a difference then you can measure it' - not something that I have ever said.
Due to how our perception works we will sometimes hear difference when in fact nothing has changed, therefore in those cases there would be no difference to measure.
Can you explain the difference between EM radiation from a transformer and EM radiation from a cable? (genuine question). Also the test did include the power cable as that was wrapped around the signal cable.
Yes the test was not made in controlled conditions, nor did it show a difference that is likely to be audible. The point of my posting this test was to show that it is possible to measure a signal for EMR effects. Tony suggested some other measurements that could also be conducted.
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Post by stryder5 on Feb 24, 2022 11:49:18 GMT
But the example does provide some evidence as to the potential for mains/power induced noise/distortion from a power cable (or transformer) to a signal cable so I'd say it's a fairly good start, if not meeting your desired criteria? Also in a "controlled environment" as you describe, you wouldn't be measuring the cumulative effects of other airborne interference which could be measured and audibly affecting the cables in our systems so I would say it may not serve to provide any useful information in relation to real world systems and listening environments. Granted that's not what you have requested as to evidence thereof but I think it's more useful measuring things in their natural environment (IE with routers/appliances dotted around with surges/spikes and all pitfalls they bring). I agree it’s a good start to provide evidence that power supplies can generate noise from a transformer, I don’t see how that’s relevant to power cables? I agree a controlled environment would do exactly what you indicated...but, to eliminate other outside interference is exactly what would be required surely? Otherwise nothing could be proved or disproved. i have to reiterate that I am a believer in cables, DAC’ etc can have an effect on our aural experiences. I was querying the belief held by some that if we can hear differences then it has to be measurable. The controlled environment would isolate any measurement however small it may be, and could be definitively attributed. Again you’re right, my request, however trivial, to demonstrate that aural cognisance needs measurement confirmation is questionable. Gary |
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Post by stryder5 on Feb 24, 2022 13:40:09 GMT
Not at all what I said. Firstly with regard to cable dressing I said 'Even I think that makes a difference'. Key word there is 'think'. I am happy to be disabused of the notion since I am aware of the frailties of human perception. 'If you can hear a difference then you can measure it' - not something that I have ever said. Due to how our perception works we will sometimes hear difference when in fact nothing has changed, therefore in those cases there would be no difference to measure. Can you explain the difference between EM radiation from a transformer and EM radiation from a cable? (genuine question). Also the test did include the power cable as that was wrapped around the signal cable. Yes the test was not made in controlled conditions, nor did it show a difference that is likely to be audible. The point of my posting this test was to show that it is possible to measure a signal for EMR effects. Tony suggested some other measurements that could also be conducted. Given your skill at finding trivial information, I would think you have the capability to research source radiation yourself. I’m sure that your original post, was in response to a question asked elsewhere and confirms that in that specific test there no defining answer. Gary |
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Post by macca on Feb 24, 2022 16:40:30 GMT
Not at all what I said. Firstly with regard to cable dressing I said 'Even I think that makes a difference'. Key word there is 'think'. I am happy to be disabused of the notion since I am aware of the frailties of human perception. 'If you can hear a difference then you can measure it' - not something that I have ever said. Due to how our perception works we will sometimes hear difference when in fact nothing has changed, therefore in those cases there would be no difference to measure. Can you explain the difference between EM radiation from a transformer and EM radiation from a cable? (genuine question). Also the test did include the power cable as that was wrapped around the signal cable. Yes the test was not made in controlled conditions, nor did it show a difference that is likely to be audible. The point of my posting this test was to show that it is possible to measure a signal for EMR effects. Tony suggested some other measurements that could also be conducted. Given your skill at finding trivial information, I would think you have the capability to research source radiation yourself. so you don't know the answer then. Fair enough, you could just have said that. |
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Post by stryder5 on Feb 24, 2022 17:20:09 GMT
Given your skill at finding trivial information, I would think you have the capability to research source radiation yourself. so you don't know the answer then. Fair enough, you could just have said that. I think that presuming to know an answer, then asking others to verify it for you is an interesting concept. If you don’t know how to research a topic and understand it perhaps someone else can help you! Gary |
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Post by karma67 on Feb 24, 2022 17:53:51 GMT
whats the point of this? gary you keep prodding macca yet you bring nothing to the debate yourself.
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Post by Bigman80 on Feb 24, 2022 18:05:54 GMT
Yeah, i agree with Jamie.
Lets call this a score draw and move on.
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Post by stryder5 on Feb 24, 2022 18:19:30 GMT
whats the point of this? gary you keep prodding macca yet you bring nothing to the debate yourself. I didn’t understand it was a debate, I asked a question. Your assumption it was a debate. What are you adding? Oli asked for this to be made a separate post, which I complied with, if you don’t like it, don’t read it! Gary |
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Post by stryder5 on Feb 24, 2022 18:20:04 GMT
Yeah, i agree with Jamie. Lets call this a score draw and move on. I agree. Gary |
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Post by karma67 on Feb 24, 2022 18:22:50 GMT
whats the point of this? gary you keep prodding macca yet you bring nothing to the debate yourself. I didn’t understand it was a debate, I asked a question. Your assumption it was a debate. What are you adding? Oli asked for this to be made a separate post, which I complied with, if you don’t like it, don’t read it! Gary debate,conversation what ever you want to call it blah blah. |
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Post by optical on Feb 24, 2022 18:28:29 GMT
To be fair there is often a thin line between debate and 'point scoring', ever watch anything in the commons?!
Anyway, anything regarding power cables affecting signal cables does interest me, if we can steer the convo more towards references/measurements AND personal experiences/theories, I think it'd be all the better for it, as I think it's an avenue worth exploring.
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