http://www.colorado.edu/physics/Web/reu/Projects/Projects 2006/Ben Zimmerman.pdf
Lots of good stuff here on the quantum Hall effect and how exotic you have to get to measure it. Especially note the 4K temperatures required.
Lots of good stuff here on the quantum Hall effect and how exotic you have to get to measure it. Especially note the 4K temperatures required.
Last edited:
Sorry Scott,
Interesting at first the link didn't fly through but trying it again it did! Great paper clearly explains how Bybee Devices work! (Humor)
As to what I call a discontinuity I would expect this to show up as an excess of 1/f noise particularly at low frequencies, not quite what used to be called popcorn noise, but similar.
Last edited:
Joachim, this is a translation problem, as well as me using a 'sloppy' metaphor as a facile description of what seems to happen. Now I understand what Scott is squawking about. It is NOT all or nothing, but it seems that it might be a zone of nonlinearity where signal through a wire might not completely track the original input. I doubt that this would violate any laws of physics, but Dr. VDH measured it decades ago, with better equipment than any of us possess at the moment, to my knowledge. He describes it thus:
" ... FFT spectrum analysis of a 500Hz single-cycle pulse at around -85dBV showed up differences: the best van den Hul cable showed a regular, evenly set of harmonics from 500Hz upwards; for one well-known American audiophile cable, the graph showed an uneven energy trend with the harmonic peaks smeared together and noticeable extra energy in the 7kHz region.
Such Characteristics are attributed to the molecular-level capacitive and diodic effects at the crystal boundaries, and they correlate with distortion and harshness in the reproduced sound. ..."
I hate to say it, but this sounds familiar to what I tend to think is going on.
Is VDH correct? He told me about some of his test equipment purchases 25 years ago, and he said they were above and beyond what was typically available, at the time, and I believe him. This is not an easy measurement to make.
" ... FFT spectrum analysis of a 500Hz single-cycle pulse at around -85dBV showed up differences: the best van den Hul cable showed a regular, evenly set of harmonics from 500Hz upwards; for one well-known American audiophile cable, the graph showed an uneven energy trend with the harmonic peaks smeared together and noticeable extra energy in the 7kHz region.
Such Characteristics are attributed to the molecular-level capacitive and diodic effects at the crystal boundaries, and they correlate with distortion and harshness in the reproduced sound. ..."
I hate to say it, but this sounds familiar to what I tend to think is going on.
Is VDH correct? He told me about some of his test equipment purchases 25 years ago, and he said they were above and beyond what was typically available, at the time, and I believe him. This is not an easy measurement to make.
Carbon cables can have a more linear group delay but the delay is higher. Maybe it whould be interesting to just put a resistor in front of a conventional copper cable and look what is happening. D.Self did measurements at very low level and did not find anything that resembled diode action. Still it bugs me that i hear differences that can not be measured and when, they are of such a low level that they should not be audible.
Our problem is that we have to satisfy more and more demandig customers. They hear differences and we must explain why our equipment sounds better or let´s say more satifying. When you measure you find that an NE5534 is perfectly adequate, when you listen the differences between passive components, solder, wire etc. show up. On a philosophical basis one could argue that a perfectly transparent chain shows up flaws in the recording so that the result is simply not digestable. To find a solution to this paradox requires more then a top degree in engineering i am afraid.
Our problem is that we have to satisfy more and more demandig customers. They hear differences and we must explain why our equipment sounds better or let´s say more satifying. When you measure you find that an NE5534 is perfectly adequate, when you listen the differences between passive components, solder, wire etc. show up. On a philosophical basis one could argue that a perfectly transparent chain shows up flaws in the recording so that the result is simply not digestable. To find a solution to this paradox requires more then a top degree in engineering i am afraid.
There is nothing to refute because no testable claims have been made. I have been reading this crystal boundary micro-diode stuff for years, there is very little substance there.
I don't doubt VDH's measurements or his equipment, but the explanation of the differences he found is another thing. Reading it, it seems that he found this a possible explanation, but there is nothing to suggest that it has any backing.
jd
Joachim,
I don't think it is the carbon cable resistance as such. That resistance (VDH quoted 28 ohms per meter for his IC's) is a byproduct of the material. The performance is attributed to the much less granularity wrt metallic cables.
Or do you propose to add resistance to emulate the group delay of a carbon cable to see if that explains the audible difference?
jd
Hello Joachim
Can you describe the reference system you use for evaluation, from your source to your speakers.
Regards
Arthur
Dependent on output stage devices and topology strongly.
Where are you in Germany? I am slowly starting to be curious ...
Things that might relate to this...
- a current website that has been referenced somewhere on DiyAudio that compares specs of a SE tube amp to an NAD solid state amp. Upshot is that the SE measures worse in the usual case, but when carefully measured in actual usage measures (and presumably sounds) better than the NAD. His graphs and figures show why
- the work of D.E.L. Shorter for the BBC
- the recent work of Earl Geddes on the GedLee Metric
The latter two show why and how standard "distortion" measurements do not correlate well with how things sound, wherein high AND low distortion products can be adjudged to sound similar, or sound different.
Dunno if this is the sort of thing you were looking for, or if you just wanted John's experiences...
_-_-bear
- Status
- Not open for further replies.