Posted in the lounge, another cable thread, sorry guys.
http://boson.physics.sc.edu/~kunchur/papers/Interconnect-cable-measurements--Kunchur.pdf
For those that no not, Kinchar has published proper scientific experiments. This one not second sourced yet, but his earlier ones have.
dave
http://boson.physics.sc.edu/~kunchur/papers/Interconnect-cable-measurements--Kunchur.pdf
For those that no not, Kinchar has published proper scientific experiments. This one not second sourced yet, but his earlier ones have.
dave
It is very important in discussing cables to distinguish between line level interconnects, which this paper does, and speaker cables. I don't think that there is much doubt about the possibiity of differences in line level cables.
But speaker cables are an entirely different matter, and this paper does not address them.
But speaker cables are an entirely different matter, and this paper does not address them.
Well he tried his best to show differences, what with sourcing and terminating with 1Megohm (when was the last time you saw that in an audio circuit), sub 1u pulses and such. Then in a desperate attempt to save the day he introduces new issues like tribolitics and microphonics - in the Conclusions section!
The only thing he showed is that different cables are, well, different.
Bad, bad.
Jan
The only thing he showed is that different cables are, well, different.
Bad, bad.
Jan
The only thing I can say is....pick up a book on EMC.
Focus on.... where are the currents flowing.
I cringe at the lack of understanding.
John
Focus on.... where are the currents flowing.
I cringe at the lack of understanding.
John
The majority of people here are going to be very satisfied with using modesty priced well built interconnect cables. Particularly if they have quality equipment that was built by manufacturers who have paid attention to grounding issues at the equipment itself.
There is no need to be overly obsessed with worrying about whether there might be some mysterious ground loop or path somewhere hidden in the system. Most people will never hear the difference, if there really is even one to begin with.
It is not necessary to become an expert on EMC in order to have a great sounding system.
Hi John, I think I know what you are driving at in your somewhat cryptic post. But then maybe I dont. If you can clarify Id be interested to know if your comment is a criticism of the paper and if so in what way.
The paper limits itself to single-ended interconnects but omits mention of the elephant in the room in respect of such ICs - ground currents.
Ground currents and mode conversion, both.
Also, there is an peer-reviewed AES paper on line level cables. Poster part of that presentation attached below. https://secure.aes.org/forum/pubs/conventions/?elib=20755
The line-level cable paper references an earlier study on headphone cables affecting sound:
"[4] A. Yoneya, “Perceptually Affecting
Electrical Properties of Headphone Cable –
Factor Hunting Approach” 147th AES
Convention, eBrief:532 (2019)"
https://www.aes.org/e-lib/browse.cfm?elib=20555
Also, there is an peer-reviewed AES paper on line level cables. Poster part of that presentation attached below. https://secure.aes.org/forum/pubs/conventions/?elib=20755
The line-level cable paper references an earlier study on headphone cables affecting sound:
"[4] A. Yoneya, “Perceptually Affecting
Electrical Properties of Headphone Cable –
Factor Hunting Approach” 147th AES
Convention, eBrief:532 (2019)"
https://www.aes.org/e-lib/browse.cfm?elib=20555
Attachments
Last edited:
Maybe that's because the so-called ground currents issue with ICs isn't really anywhere near the problem that some have made it out to be. At least not in most typcial home audio systems.
So rather than being an elephant in the room it is much more like a mouse.
Some reference material on ground noise in audio systems attached below. Sometimes installing a top-notch power conditioner with well designed common mode chokes can produce surprising results. Audio spectrum analysis may not prove very useful for system assessment when mode conversion and demodulation occur since the symptoms may not show up very well in steady-state type measurements.
The first paper deals with professional audio issues in large venues. Not really relevant to home audio at all.
And the second deals with equipment design by manufacuters. Again, not anything we can do much about as consumers. Just need to assume that the manufacturers have chosen good design paths and buy products from those that you trust.
And the second deals with equipment design by manufacuters. Again, not anything we can do much about as consumers. Just need to assume that the manufacturers have chosen good design paths and buy products from those that you trust.
Who are the 'some' here? Why do you consider it a 'so-called' issue?
What do you consider a 'typical home audio system' ? It would be useful to have a concrete example, who knows I might agree with your point if I understood the context of your making it better.
Then the issues in the paper - transient response, frequency dependence of shunt capacitance, signal propagation speed, reflection sequence - would be mosquitos.
I am comfortable with what you have stated. Most will not hear a difference.
What I do not care for is measurement and conclusion based on tests which do not reflect actual use. Pretty much everyone believes the return current of a shielded IC returns along the IC carrying the signal when two IC's are present. Simply, no.
Tests of a single IC in solitary has very little meaning.
I point out that I do not worry about this, just stating engineering facts...
John
As abraxalito pointed out, ground currents are of concern.
When a system has two IC cables, and as well a ground loop formed by three prong plugs, the signal currents (and as a consequence, ground loop induction of interference) are not what is expected.
John
So just to be clear about the case with a single IC. Let's say for example an amplifier and a CD player. Can we pretty much conclude that there is no ground current issue in this case.
No we cannot be sure there is no ground current. The CD player I currently use has an external SMPSU wall-wart with just two pins (L and N) for its plug, most certainly that will introduce common-mode ground currents in the ICs between it and the amp which has a 3pin plug.
OK, but let's talk about equipment with built in power supplies and conventional AC line cords. Both cords plugged into the same AC wall outlet.
Conventional AC line cords implies class I electrical safety category? Both CD player and amp having 3pin plugs? If so I'm not sure I've ever met a class I CD player, mine have all been classII (aka 'double insulated').