John Curl's Blowtorch preamplifier part II

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BTW Sy I'll bet my shelf of books on physics and electrical engineering has more books on it than yours does. Since I don't design amplifiers or smash atoms for a living I haven't read them in awhile. About 40+ years.

Can I get in on that bet?

And silly me, I refer to my library often. When I just moved the guys around here complained about how most of my stuff is books. Of course they know I lost most of them in the flood 0f '04, they don't know I lost many also in '92.

I must remind my self that after '04 a number of friends sent me replacements from their collections otherwise some of the books would have been difficult to find.

Oh yeah, shelf? I find I have to build a few new bookcases each year.
 
If you keep overfeeding Trollminded in this thread I think he might just Blow :eek:

I am trying to determine if there is a rational engineering justification for expensive high end audio electronics that distinguishes it from its best far less expensive competitors. So far I can't find any.

Then I would recommend starting your own thread instead of the usual troll(minded) course of defecating in a thread that has a lot of foot traffic in the vain attempt of spreading your spore, or with the name of someone you recognise and take vicarious enjoyment from being associated with.

Yes start your own thread and see how long it lasts, at least you might get a metric of some note; number of posts/views that you can then claim in some manner relevant is justifying your opinions .

rgds
James
 
If you keep overfeeding Trollminded in this thread I think he might just Blow :eek:



Then I would recommend starting your own thread instead of the usual troll(minded) course of defecating in a thread that has a lot of foot traffic in the vain attempt of spreading your spore, or with the name of someone you recognise and take vicarious enjoyment from being associated with.

Yes start your own thread and see how long it lasts, at least you might get a metric of some note; number of posts/views that you can then claim in some manner relevant is justifying your opinions .

rgds
James

I am getting the distinct impression that you do not enjoy reading my postings. I suggest you pass over them and read something else when you see them.
 
I am getting the distinct impression that you do not enjoy reading my postings. I suggest you pass over them and read something else when you see them.

Well, this morning, I've appreciated your romantic contributions immensely.

Had it not been for them, Steve would not have written what I'm sure will be post of the week, (however evanescent). And, without them I finally, after seven years, at last have had a post removed by some mysterious power.

So, all in all, thanks to you, it's been a morning of innocent merriment - not to mention some wonderment.

To say the least, I'm grateful. Such blessings come rarely.:cool:
 
Sometimes the results ARE null.

as they often are, when done by paid by the word 'types'

An externally hosted image should be here but it was not working when we last tested it.


Prof Wiseman also regularly acts as a consultant,
and has recently worked with Derren Brown,
The MythBusters, CBS's The Mentalist,
Heston Blumenthal, Nick Cave,
and the West End play 'Ghost Stories'.

Richard Wiseman
 
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Subjectivity is a major feature of the high end audio
landscape. As I said, the difficulty is entirely between the
ears, and if you read much of the literature of cognitive
psychology you have to conclude that it is hideously
complex and not well understood, not to mention varying
dramatically between individuals.

Sixty years ago or so, measurements corresponded better
with subjective opinion, but I think that was because the
equipment didn't measure very well. Now it generally
measures very well, and the objective technical problems
are largely solved.
All true, but there are cognitive psychology researchers, and then there are psychoacoustics researchers. The latter have a much better idea of what happens in our ears and between our ears, because they don't waste much time trying to figure out the rest of what's going on in our heads.

J.J. Johnston has given many intriguing talks at local AES meetings. One important result of this research is the discovery that distortion increases the perceived loudness without increasing the dB level on standard meters. He has research showing the ear+brain response to loudness based on frequency content, not mere RMS levels. Although the VU corresponds quite well to perceived loudness, it's far from accurate enough to calibrate levels for a valid A/B/X comparison.

One conclusion from this research is that vinyl sounds 'better' than the same music on CD because the amplitude-dependent distortion inherent to vinyl makes it sound louder in the higher level passages, and thus increases the perceived dynamic range, even though output meters would not show any difference in the average VU level or peak-reading level. My assumption is that if we could meter the perceived loudness more accurately, then we could adjust the vinyl listening level down to more closely 'match' the CD listening level, and then we'd hear that the digital source sounds 'better' due to lack of distortion (or, at least, significantly reduced distortion).

I hope to develop a new meter technology which leverages this research to display a value which more closely tracks perceived loudness. Thus, it would be easier to compare the subjective performance of two amplifiers without the old "louder is better" phenomenon taking over.
 
rsdio said:
J.J. Johnston has given many intriguing talks at local AES meetings. One important result of this research is the discovery that distortion increases the perceived loudness without increasing the dB level on standard meters. He has research showing the ear+brain response to loudness based on frequency content, not mere RMS levels. Although the VU corresponds quite well to perceived loudness, it's far from accurate enough to calibrate levels for a valid A/B/X comparison.

What type of distortion is he talking about? Just having more distortion doesn't make the sound better or louder.

What kind of test did he do to come to that conclusion?

People can just copy a LP to a CD, but they usually aren't too impressed with the results, from the accounts I've heard, anyway.
 
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