I'm just now catching up on this fascinating, ground-breaking (sorry...) thread!
I'm also posting here so I remember where I was in the thread - I want to hear these before reading responses, and especially before reading a "spoiler" post telling what's what.
One more thing, there's something missing here - what's the input impedance of the AD you're sending this "signal" into?
Some might think this would make it an unfair comparison, but (for a different example) speaker cable has it really bad, a really high current into a really low impedance.
Another thing - if you make more recordings, PLEASE don't tell us which channel is banana and which is potato - I want to see who identifies which is which.
I'm getting the MP3s. I'm tempted to get the FLAC but I have too hard a time telling the difference between 'real' and 320k to bother.
I'm also posting here so I remember where I was in the thread - I want to hear these before reading responses, and especially before reading a "spoiler" post telling what's what.
One more thing, there's something missing here - what's the input impedance of the AD you're sending this "signal" into?
It could be instructive to put a lower resistance at the AD input, to make it more of a resistive divider. Try 10k or 1k - or whatever it takes to make a nominal 3dB drop in signal. This might need a buffer (good headphone amp?) on the AD output to drive the thing.
Some might think this would make it an unfair comparison, but (for a different example) speaker cable has it really bad, a really high current into a really low impedance.
Another thing - if you make more recordings, PLEASE don't tell us which channel is banana and which is potato - I want to see who identifies which is which.
That's a bit of history I didn't know about pencil lead.
As for graphite, that's a form of carbon, and Alexander Graham Bell's first (and only?) microphone design used a diaphragm vibrating against a small container packed with carbon to get a variable resistance. While it's not in such wide used today, it was the highest quality microphone design at the time (okay, it was the ONLY microphone design).
There was the East-Coast Vs. West-Coast (USA) sound (first it was speakers, then it was rap music), next will be The Itallian Sound! Opera fans will love it!
But, but ... I can hear Them now, with Their Pseudo-Scientific Explanations - this test ONLY confirms that there's little if any difference between copper and these other crude substances - but Gold and Silver just HAVE to be Audibly Better!
Aha, an actual value for impedance (I presume the driving output impedance was much lower, low enough to be considered insignificant). That will be helpful when, er, if this experiment is repeated.Thanks for taking the time to listen. The input impedance of the A/D stage was 20K. There was some attenuation, which was made up for with the input volume control.
The banana had the highest impedance.
I just listened to the MP3s, first at moderate volume (Audiophile 2496 PCI card, old Kenwood amp, Infinity RS-125) and couldn't hear a difference. I switched to my Sony MDR-7506 headphones (not flat, not perfect, but if I am to hear any difference, it would most likely show up through these), cranked it up a good bit, but still heard no difference.
I DID hear the skip in file D at 29 seconds, but I didn't think much of it - I just assumed it was some program running in the background eating up processor cycles. On the other hand, this is a 3GHz quadcore with 8 megs RAM, and I've done a good bit of audio recording and multichannel playback with no glitches while other stuff runs, so I SHOULD have suspected the file.
I think I heard the skips the first time I listened as well and put it down to something on my HT box interfering, it wasn't until I put the headphones on my laptop and played the tracks a few times that I noticed it was always track D, and then I payed more attention and saw it was always at the same spots
I'm still rather amazed that I can hear absolutely no difference between the tracks! it would be interesting to synchronize two and swap between them rather than listening to a whole track and then another, that *might* make it easier to spot a difference...
Tony.
I'm still rather amazed that I can hear absolutely no difference between the tracks! it would be interesting to synchronize two and swap between them rather than listening to a whole track and then another, that *might* make it easier to spot a difference...
Tony.
The idea is being picked up by commercial types already!
Pear Cable Audio Cables
Listened to the four clips for a second time, and I found no significant difference. Old ears too.
Pear Cable Audio Cables
Listened to the four clips for a second time, and I found no significant difference. Old ears too.
Except that I have avoided that, the original file is included!
If it's "better" than that, well.... you know.I tried to measure the DC resistance of the potato and could not. It kept getting higher and higher, like a cap charging up. I found that the potato would charge to about 0.8V and it would hold. Don't know how, both probes were stainless steel, not dissimilar metals.
I used the ABX plugin in FOOBAR to do just this. Not much, if any, difference that I can tell. Very surprising.
Sorry about the glitches in D. I could fix that, but want to leave all as is.
I could convince myself that any one of those are the originals.
This is with Laptop > usb soundcard (cheap but half-decent) > Behringer CX2310 > Samson Servo 240 > Behringer B2031P
... plus subwoofers.
Is it worth trying a couple of other tracks through these, er, interconnects?
I'd quite like to hear this:
Morphine - Buena - YouTube
Where there's a bit more going on.
Chris
This is with Laptop > usb soundcard (cheap but half-decent) > Behringer CX2310 > Samson Servo 240 > Behringer B2031P
... plus subwoofers.
Is it worth trying a couple of other tracks through these, er, interconnects?
I'd quite like to hear this:
Morphine - Buena - YouTube
Where there's a bit more going on.
Chris
I listened to the mp3 files yesterday night through PC speakers. I couldn’t spot any difference.
Today, first think after waking up, before coffee, was listening to the flac files through AKG240 headphones.
Initially I said A,D,C,B in terms of presence.
After the second listening, I wasn’t sure for the order of difference.
Then I listened to them many times in random order. I can’t say there is a difference, let alone any order.
The more I listen to them, the more I can’t tell one from the other (except through the glitch on D)
I knew that radio amateurs were using trees as efficient antennas.
Thank you Pano for the audio experience.
George
Today, first think after waking up, before coffee, was listening to the flac files through AKG240 headphones.
Initially I said A,D,C,B in terms of presence.
After the second listening, I wasn’t sure for the order of difference.
Then I listened to them many times in random order. I can’t say there is a difference, let alone any order.
The more I listen to them, the more I can’t tell one from the other (except through the glitch on D)
I knew that radio amateurs were using trees as efficient antennas.
Thank you Pano for the audio experience.
George
A quote from the documented origin of the idea (*)
http://w5jgv.com/tree_antenna/George%20O%20Squire%20Tree%20Antenna%20Patent.pdf
(*)Here for a more recent study:
http://w5jgv.com/tree_antenna/1975%20January%20Ikrath%20IEEE%20tree%20antennas.pdf
Come to think of it, this is even stranger than I thought.
I don't know how to Google this and I never thought about it before, but there is a fundamentally different kind of electron flow going on than in normal conductors. No free electrons here. The transport must be ionic.
I would never have guessed that the propagation speed in ionic transport would be high enough for audio, altough I am sure someone must have measured it sometime.
Edit: what I mean with propagation speed is that two electro-chemical reactions need to take place at both cathode and anode, the electrons flow through the circuit, this goes fast enough
Spot on. Different conduction mechanisms. Molecular wire - Wikipedia, the free encyclopedia
Can a chemist pop in please?
George
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Pano
For audio frequencies, I think that organic conductors can be studied by performing impedance scans. Dielectric spectroscopy - Wikipedia, the free encyclopedia
Many of the different conduction mechanisms are represented by different standard models. See here
EIS Spectrum Analyser
For advanced analysis:
Potentiodynamic Electrochemical Impedance Spectroscopy
George
For audio frequencies, I think that organic conductors can be studied by performing impedance scans. Dielectric spectroscopy - Wikipedia, the free encyclopedia
Many of the different conduction mechanisms are represented by different standard models. See here
EIS Spectrum Analyser
For advanced analysis:
Potentiodynamic Electrochemical Impedance Spectroscopy
George
There's all sorts of ways that charge is transported in solids (including polarons and solitons). But since this is AC, it's a field transmission- the charged entities have a short path and basically just jiggle. The way different mechanisms can be distinguished, using relatively simple means, is usually through temperature dependence measurements.
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