Guys,
Be careful with the 1/4 wavelength assumptions used for rf stuff. It is generally misapplied w/r to audio.
I do use transmission line theory for low impedance loads and 50 to 100 foot twisted pairs for a rather esoteric application. When you go through the equations, you find that the settling time of the system can get rather high. In my application, I need a BW of 10 kHz, and driving 3 ohm loads with twisted pairs leads to latency problems due to that settling time, even at the 50 foot length.
Now Ed is playing with kilo foot lengths, and I am confident he has no clear understanding of the temporal problems associated with longline propagation using a high impedance line driving a very low, frequency dependent load.
Tom Danley gets around this problem in his tower setup by the use of multiple parallel cables.
John
Be careful with the 1/4 wavelength assumptions used for rf stuff. It is generally misapplied w/r to audio.
I do use transmission line theory for low impedance loads and 50 to 100 foot twisted pairs for a rather esoteric application. When you go through the equations, you find that the settling time of the system can get rather high. In my application, I need a BW of 10 kHz, and driving 3 ohm loads with twisted pairs leads to latency problems due to that settling time, even at the 50 foot length.
Now Ed is playing with kilo foot lengths, and I am confident he has no clear understanding of the temporal problems associated with longline propagation using a high impedance line driving a very low, frequency dependent load.
Tom Danley gets around this problem in his tower setup by the use of multiple parallel cables.
John
well free space 10kHz wavelength is 30km. so would have to be several thousand times slower in the wire. Not sure even trying hard you could slow it that much, but if you can sure JN has done it
The basic problem has to do with the impedance of the transmission line and the impedance of the load. With a 4 ohm load and a 150 ohm line, a 150 volt pulse will drive 1 ampere down the line. But a 4 ohm load would draw 37.5 amperes.
The load's V/I requirement is not the same as that of the wire at the wire's prop velocity. The wire cannot transfer what the load requires at the base prop velocity of the wire.
Gonna hafta go, using an I-pad and the charger's at home. Killing time, cause I've a lot of it to kill. Sigh.
John
I noticed that and looked quite askance at it, but I didn't want to go to the trouble of building an explanation to refute it. To me the point is not so much whether MH got his calculations right. What he claims looks quite odd, and technically I think you are right.
What I think the point really is to me is what I have been saying, which is if you can't hear, it doesn't matter what the physics is. I say this because for people who believe in wire effects, even if their theoretical guy made a mistake, they still believe there is something to hear. MH being proven wrong in the technical details of his article isn't going to convince them otherwise. They will just look for other evidence to confirm what they already believe.
And just by some very unlikely chance, what if they are hearing something, whatever it is? It wouldn't be the first time scientists told people they were crazy because the scientists know better. Of course, it happens in medicine much more often than in physics. In 1970 if you had Lyme disease, they told you it was all in your head, You're fine, all your tests are normal, your're just faking and lazy and need to stop imagining things an go back to work!
So, my preference is to allow that I don't know everything with complete exactitude. And even in physics there are unsolved problems. We know fundamental physics has to change, but we need a breakthrough to figure out how exactly. Can we keep locality and causality? I don't know.
Anyway, if someone can show me they can hear wire effects, I will try to figure out how and whatever is going on with that. But as I said, the ball is in their court.
And I haven't even started to talk about the neuroscience and cognitive psychology of hearing, and of how belief systems work in general.
Right, so you get an inverted reflection back to the source, and if not absorbed there, then you get lots of reflections back and forth before a steady state is reached. Am I missing something here?
Performs better in what sense? The twisted one is better for minimizing coupling with stray magnetic fields. That's normally why we twist wires.
Of this I am curious... have any of you fabricated identical sets of interconnects OTHER THAN the metal used? And, of course then listened to them? I do mean identical, other than the metal, same solder, same connectors, same length, same stranding, same geometry, same dielectric. For example, copper and silver?
The expectation is that they ought to not sound different, yes?
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The expectation is that they ought to not sound different, yes?
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I am incuding the entire interconnect. So use reasonable quality RCA jacks. I usually use Neutrik. I use a pair of standard oscilloscope probes to pick off the signal at each end. There are lots of possible issues. But you are welcome to try it and see what actually does cause changes and what doesn't. Be sure to try both a sine wave and filtered noise. Even try a few different cables to see which artifacts change with cables vs setup.
JN why do you think my cable is higher impedance than my load? It is a custom made cable, a bit expensive and contains IP so the details will remain a mystery. Definitely not patentable. Today I finished building my launch boxes. Quite a few parts all capable of handling a bit of current. Took a bit of testing to get things right. I have also explained that my load does not vary with frequency. A simple bit of kit takes care of that.
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I have some copper wire and some otherwise identical wire that is silver plated. I haven't noticed any difference in sound, but I haven't been looking for for any either. Might be interesting to try it with aluminum, but then you couldn't use the same solder, I don't think.
Are you looking differentially at each end? You would need to get the common mode element properly tweaked out to see what is happening. I have dealt with this on HDMI cables (differential signalling at 4 GHz) and the care needed to get good data is immense. As is the care to avoid static discharge.
Making a cable with an 8 Ohm impedance is not that difficult (Polk Cobra Cable anyone?). Getting a dynamic speaker to look resistive takes some fiddling at the far end of the cable but no new science.
I have made several variations on the low Z cable and they all worked. I think the most interesting were some large pieces of Flex PCB material. 4" wide by .02" laminate inside. Extend the source impedance of the amp to the load. I'm not sure what the settling time on those would be. They are long gone now.
I was supposed to defend the Hawksford stuff at one point. It was not possible so I avoided the whole pitch.
The real challenge if there is something is to identify how to measure it. If its not voltage + current what is it? What else can go down a cable and affect the vibrations of a transducer at the far end? Neutrino modulation?
If people couldn't distinguish copper from a potato, I think you have your answer.
Not in the current example. It takes 0.1ohm to get 1nV out of 10mV in an 1Meg voltage divider. For a regular coax centre conductor 0.1ohm is about 1.2 meters of cable length.
Now, why am I wasting my sleep on this new "you are all dumb" charade?
The guys from CALTECH will be there and we plan on a discussion around the actual schematics. The socket in question is the active supply setting the laser current/amplitude. It needs 1 part in 10^^9 amplitude stability (yes PSRR
BTW it's in Hanford a place you must know enough about to have to kill us if you talked.
Hanford was a fun tour lots of messes when I was there I was told the fences kept the hot tumble weeds in not people out. lots of PhDs and class Q clearance guys my best man and friend even had one.
?Was it Hanford where the top blew off of something and nailed someone's head to the ceiling, and it was so radioactive that it had to be buried separately from what was left of the rest of the body?
And to think I told the guy on Art Linkletter's House Party that I wanted to grow up to be an atomic physicist. But those were the days of Our Friend the Atom.
A great scifi from earlier days still: Nerves, Lester del Rey iirc.
And to think I told the guy on Art Linkletter's House Party that I wanted to grow up to be an atomic physicist. But those were the days of Our Friend the Atom.
A great scifi from earlier days still: Nerves, Lester del Rey iirc.
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