John Curl's Blowtorch preamplifier part II

[Esperado]

Originally Posted by Jonathan Bright

"Werner Heisenberg lived here..........probably."

He died too soon?

[bcarso]

Originally Posted by DF96

Could someone remind me of the mean free path for electrons in, say, normal electrical copper? How far from the BQP would they have to travel before all beneficial effects are lost? Mean free time too?

The late (lamentably!) Peter Carroll Dunn has a short table of properties of materials on the front pastedown of his Gateways Into Electronics, which includes the mean free time of electrons in copper, tau sub F, as 2.4 * 10^-14 s, and the average thermal speed of electrons along one axis <|u|> as 5 * 10^6 cm/s [ EDIT: at 290K ]

I have to plug this book again as it is just astonishingly good. ISBN 0471254487.

[sofaspud]

Just looked it up on Amazon... odd pricing (new hardcover from $10, Kindle edition $136!), but the first review is from none other than Winfield Hill. And it's very positive.

[scott wurcer]

Originally Posted by gpapag

Even harmonics are present when waves are non symmetrical. Such an asymmetry adds a DC component.

George

No! There is no way to add pure sines and cosines algibraicly to create DC. There has to be explicit DC present or modulation/non-linearity.

[SY]

Originally Posted by gk7

You obviously were already convinced beforehand that there will no differences to be heard, so the outcome of your test (blind or not blind) was to be expected.

That's a reasonable comment. I was only interested in the measurements to verify or refute specific fact-claims; the listening "tests" (I use scare quotes because I didn't do enough to have this rise to the level of what I'd consider a test) were only for my own curiosity, and I didn't say anything about them until I was pressed about it.

[scott wurcer]

Originally Posted by jcx

when they show the Cramer-Rao boundary for the stimulus on the same plot we get excited

They wouldn't hear of it.

[Mr. dB]

Originally Posted by Esperado

He died too soon?

It's hard to tell.

[scott wurcer]

Originally Posted by KBK

Where's the naysayers when the chips are down? they're off hiding. readying to attack again, no doubt.

No in fact as several of us pointed out, non-linear processing is not subject to this "uncertainty principle". As to hearing specifically this has been studied since the 70's.

"Fourier uncertainty principle" is not a term you see often, to me this is a deliberate association with Heisenberg purely for sensationalism.

[SY]

Originally Posted by scott wurcer

"Fourier uncertainty principle" is not a term you see often, to me this is a deliberate association with Heisenberg purely for sensationalism.

I found it very useful for pedagogical purposes when I taught basic QM- my students intuitively grasped the concept of how long it would take to use beat frequencies to tune a bass; from there, going to quantum uncertainty was a much smaller leap.

[tvi]

human-hearing-is-highly-nonlinear

Uncertainty principle - Wikipedia, the free encyclopedia
"In the context of signal processing, particularly time–frequency analysis, uncertainty principles are referred to as the Gabor limit, after Dennis Gabor, or sometimes the Heisenberg–Gabor limit."