John Curl's Blowtorch preamplifier part II

[jan.didden]

Originally Posted by 1audio

Can you post a link or copy of the paper? I would like to see it. It sounds like the audio equivalent of differential gain/differential phase measurements. If so there are ways to quantify it.

http://www.linearaudio.nl/library%20misc.htm

[PMA]

Thanks Jan, valuable papers.

[Joachim Gerhard]

Can one be 90% dead ?

just a joke....

[scott wurcer]

http://www.colorado.edu/physics/Web/...0Zimmerman.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.

[simon7000]

Originally Posted by scott wurcer

http://www.colorado.edu/physics/Web/...0Zimmerman.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.

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.

[john curl]

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.

[Joachim Gerhard]

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.

[PMA]

Just an idea, how about transient noise modulation, and Comodulation Masking Release. And a Neural Edge-Detection - Auditory Sensitivity on Modulated Noise.

[scott wurcer]

Originally Posted by john curl

I do not, and nobody has said that there is a 100% dead zone, just a change in linearity, enough to be what we usually call distortion. Please don't tell me that everyone can easily measure this, or refute it.

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.

[Joachim Gerhard]

Noise can raise sensitivity to low level information.
How else whould a shark in a noisy environment be able to detect pray hundreds of meters away. I have a tree that grows in hot and water shy environments that attracts 4 types of butterflies i have not seen in ages.