John Curl's Blowtorch preamplifier part III

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I can't believe I've made it to 69 without a single prescription to fill for anything. I'm probably doing without any number of things that I should be taking but I'm not dead yet.

Thankfully most of the pill bottles I have had to read have been for other people, except after my eye surgery, and they gave me a paper with big print. 🙂 Written instructions for electronic devices are worse, but luckily the more complex the device, the fewer the instructions. Most are on pdf anyway do I can zoom to 150% and read them.

I hesitate to post this Ed because it is very personal but this is an interview with my father's navigator shortly before he passed away. Please listen to it you might be amused.

YouTube

Thanks for sharing that. My wife's uncle Don (actually her mother's cousin Donald Campbell) flew Lancaster bombers. He was shot down over the English Channel and was picked up by a German U-boat. Because he was an officer the German captain saluted him and said "For you, my friend, the war is over." He spent the next few years as a POW. It got bad toward the end as the Germans were retreating and forced the prisoners to march, some never made it. He was lucky and came home and had a family and a good life. I went to his funeral a few years ago, and to his wife's funeral a few months ago.
 
Sounds like the same bombers as my father flew... across the channel. B16 navigator. At the end of the war, he was the only person left alive that started in the beginning of the war of those bomber groups.... all others died.

But he lived on to make it all the way to 69.

-RNM
 
@ PMA,

Any description how it works (HF filtering)? Maybe HF filter would be much cheaper and much more effective?

That's a different question, isn't it?

@ DF96,

If you think about the alleged filtering action added to a potential divider consisting of a piece of wire+Bybee feeding a typical audio equipment impedance (say 10k-100k?) then it should not take you long to work out that any filtering (even if real) is so hopelessly small that only people with real Golden Ears will hear it and even then only when they know the device is present.

I know that it is hard for some people to understand, but if I try to give another interpretation of someone else's post, it does not mean the posts reflect my personal point of view on the matter.

Besides that, a german lab did some measurements on some "Bybees" a couple of years ago and one of these measurements showed indeed an effect that seems to be something like "lowering the noise floor substantially broadband, while the level of the sine wave remained constant" .

I've posted the figure along with some (translated) description of the measurement process, albeit too sparse for any exact replication, and hoped that some other members could have the same/comparable instrumentation to try it out.

I don't have an idea which way such an effect could be implemented (contradicts a lot of what I think to be true) so it is easy to conclude it must have been a simple measurement error.
OTOH the guy running the lab is quite capable....

IOW, you don't know of any evidence that skin effect's impact is audible at high audio frequencies.

The OW, that you should have understood, were that I wasn't talking about audible effects of the skin effect.

Got it.

Deflection and redirection noted.

Did I already mention Feynman talking about the easiest one to fool?
You did it again, even twice within 6 words.
 
@ PMA,



That's a different question, isn't it?

@ DF96,



I know that it is hard for some people to understand, but if I try to give another interpretation of someone else's post, it does not mean the posts reflect my personal point of view on the matter.

Besides that, a german lab did some measurements on some "Bybees" a couple of years ago and one of these measurements showed indeed an effect that seems to be something like "lowering the noise floor substantially broadband, while the level of the sine wave remained constant" .

I've posted the figure along with some (translated) description of the measurement process, albeit too sparse for any exact replication, and hoped that some other members could have the same/comparable instrumentation to try it out.

I don't have an idea which way such an effect could be implemented (contradicts a lot of what I think to be true) so it is easy to conclude it must have been a simple measurement error.
OTOH the guy running the lab is quite capable....
If that's not UD (Mark's politically correct term) I don't know what is. Let's wait to see if it has a positive outcome eh Mark? 🙄
 
Hi Bob and Johnego (and everybody else), here are the CD quality Test Dept files -
00 - Two Flames Burn - ORIG.wav
01 - Two Flames Burn - GC.wav
You should find the same kinds of changes, only better.

Cheers, Dan.

So no takers from the ‘fear of fud’ group to send some music samples with slight differences my way for sighted listening analysis?

Putting it on the line here 😛
Yes, I did just now.
If you have a favorite track just say it, I may have it in my multi TB music collection.


Dan.
 
The idea was that calling something FUD could still be a useful challenge (more to do with the way it tends to be used here rather than the original definition) but maybe it was better to drop the fear element because of it's negative implications for some IIRC.

The way the term "FUD" is used in audio forums is/was indeed to discredit a person (or the ideas) by marking them with the label "FUD" - usually still while having no arguments.

So what kind of challenge is presented by using "UD" ?
Given the fact that we are mainly dealing with probabilities and wrt measurements with uncertainty (for some reason we are no longer using the term "measurement error" but "measurement uncertainty" instead) does it make any sense?
 
It was only a challenge in the sense of there was a lack of evidence, it was really more of an observation that there was a lack of evidence. IIRC Mark's theory was that by dropping the fear element it could be more likely to result in progress towards a more definitive answer. I can't be certain of that of course, it's just my interpretation of what he was saying.
 
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