Unfortunately most of those inverters generate a lot of HF hash. Maybe an older Elgar linear power source if you can deal with the fan noise.
At some of the frequencies now commonly found in many households (which can extend up into the GHz region), one meter could potentially make a substantial difference.
That's why I avoid the 5mv pr division setting on my oscilloscope, when you zoom that hard everything gets ugly/distorted.
This discussion to me makes sense in a theoretical/intellectual exercise, but practical no.
Guess I'm not a true audiophile, certainly lacking the golden ears, and my speakers, and for that sake all speakers add distortion in percent region, why bother about 0.000 something .
Guess I'm not a true audiophile, certainly lacking the golden ears, and my speakers, and for that sake all speakers add distortion in percent region, why bother about 0.000 something .
If Nordost cable "outperforms normal cables by a mile" it should show up in frequency domain as well. And if somebody makes such a claim or claims that the last meter makes a substantial difference the onus is on the claimant the show the evidence. Otherwise it is just hand-waving.
https://en.wikipedia.org/wiki/Hand-waving#:~:text=Hand-waving (with various spellings,doing nothing effective or substantial.
Why? What current were the cables tested at? Something realistic for a big power amp?
Most residential buildings have many meters (or yards) of unshielded wiring before the outlet. Why would the last meter have substantial impact? And do you have any evidence of this substantial impact or are you just hand-waving?
Not clear that it would. A lot of the reason for looking at the time domain view is to see if it gives any useful insight. Same for the frequency domain view. FD is easier to interpret when not too many frequencies are present. TD view may have have its own limitations as well.
If there is a shield over the cable it may act as a distributed filter cap as well as a shield. Also below very high frequencies it might act as a type of circular waveguide below cutoff attenuator. As a rough approximation, for a 2cm diameter circular waveguide, frequencies below about 4GHz would be exponentially attenuated from propagation down the inside of it. Some general information: https://blog.samtec.com/wp-content/..._2020_waveguides_modes_cutoff_frequencies.pdf Of course the situation is made more complicated since there are also wires inside the shield. Another view might be as an improperly terminated non-uniform transmission line structure. If there is an abrupt change in Z0 where the AC line transitions to the power cord, then RF will tend to be reflected due to the mismatch. That may help RFI/EMI from propagting through in or out past through interface. Also, this brain-dump rambling is not meant to cover the exact situation of a AC power cable. Its is only to illustrate that Measurements need to be made for physical effects other then FR and SINAD type stuff.
There is also the possible issue of Lorentz force causing motor effects in the power cable conductors. This effect has been casually observed in shorted speaker cable wires that then became speakers of a sort due to the Lorentz forces. Again, more measurements would be needed.
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EMI EMC on the power line is a real issue. Here is the mil spec MIL-STD-464C which covers that stuff. Power line stuff inclued so many noise generators of so many kinds that filters will make some difference. One way to quantify this would be to drive a signal into the line and see how much makes it through to the output circuits, even speaker wires. While not trivial its not that hard. Its unlikely that magic metal wire would make a difference. I can see how different construction could attenuate conducted noise differently.
However if I spent that much money on a cable you can bet I would hear it, even if its not plugged it.
However if I spent that much money on a cable you can bet I would hear it, even if its not plugged it.
I am happy to report, I bought some more popcorn for use in my air popper.
Discussions about the "last meter" can be so entertaining.
EMC/EMI is so misunderstood. It's rather fun reading this stuff.
John
Discussions about the "last meter" can be so entertaining.
EMC/EMI is so misunderstood. It's rather fun reading this stuff.
John
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OMG.
I guess I need to find a Tito's vodka laced butter for my popcorn.
Lorentze forces on a power cable is actually not significant. However, in a 5 tesla magnet running 16 kiloamp currents (sorry, work stuff), well, yah, duh.
Please keep the discussion in the domain of actual stuff.
John
ps. If you really want to discuss lorentz forces on a power cable, use the equations to calculate the force, then the modulus of the insulation, twist, or jacket used to hold the conductors in place to determine the movement of the conductors in the field, and then the generated EMF of conductors moving within that field to generate voltage.
Or, learn EMC/EMI to better understand the issue.
pps. Motion due to lorentz forces are second harmonic. It gets complicated, I know..life is rough
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So you think the follow post describes something purely imaginary?
https://www.diyaudio.com/community/threads/daves-attempt-at-a-null-test.403488/post-7459087
Why don't you go ahead and show us few sample calculations of all that stuff however you typically like to do it, say, like maybe for the speaker cable case sawyers described? Thanks!
Please do elucidate, professor.
I'll get the popcorn started here.
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