John Curl's Blowtorch preamplifier part II

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I am sure none of the "true believers" will admit being fooled by these things, but let's post them anyway: they're really fun for those willing to accept them.
After This Audio Illusion, You'll Never Trust Your Ears Again
https://www.youtube.com/watch?v=kzo45hWXRWU
Audio illusions include the Shepard tone, known as a sonic barber's pole | Daily Mail Online
Auditory illusion - Wikipedia, the free encyclopedia
This is just a small sample: the number of ways a system can be fooled or led astray is more or less proportional to its sophistication and complexity.

Our sensory systems, even taken in isolation are extremely complex; when two of them are involved, we are talking of complexity².

That is just what can happen at the lowest, thalamic input level: when interactions with the cortex are involved, things really go out of control
 
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Some time ago i made this very inexpensive headphone amp for my Frickelfest buddies
( Frickelfest is something like the German version of Burning Amp ).
Here you see how i design economical with Opamps.
 

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But they affect the numbers (noise, distortion, power), so this makes little sense.

So, when building something, does it make any difference if we listen first and measure after, or measure first and listen after?

Yes, listening first is a complete waste of time. Listening aftewards is relaxing if you were able to get the measurements right.
 
it is just a dedicated calculator that help a design, saving calculation time.

And yet you admit you're never far off, provided that the parameters of the device model are accurate.

On the other hand, when it comes to listening, you just assume your own parameters are optimal at any moment.
And without any form of authentication, how does that work ?
 
Hmmm, so it's goes something like this ...

1. It has been demonstrated that people's perceptions can be fooled, or distracted into not perceiving "reality"
2. Someone have perceived something that I'm not comfortable with, that irritates me, that I have not personally experienced
3. Therefore, that person has been deluded, and has not understand the reality

Okaaay, got it now!! :), :up: ...
 
diyAudio Senior Member
Joined 2002
Hi,

No measurement can tell me why, no blind test can tell me why. In fact, quite the opposite, measurements tell me that most tube gear is junk, it quite usually has a THD factor of >3%, and I have seen intermodulation measurements of 5%. And the same occurs there as well, a better measuring unit ends up sounding worse than the poorer measuring unit, not always, but it does happen.

I agree that most of the tube gear measures like junk yet does not sound like it.
If SS gear would measure like that it would sound like junk.
Ever wondered why?

Nonetheless all of my tube gear measures at least as good as the best SS gear and to my ears sounds better. Why?

I think the answer is simple enough.

Cheers, ;)
 
How an optometrist works out your prescription is how you fix up an audio system - endless swapping between subtle variations in lens specs, but no crap about whether "one is better than the other" - just read the bottom line, which combination allows you to see those characters most clearly ... dunno how a DBT would work here, somehow ...
 
How an optometrist works out your prescription is..endless swapping between subtle variations in lens specs..just read the bottom line..which combination allows you to see those characters most clearly

Would you like some time to reconsider that one, before I'll give you the correct answer, Frank ?

(for instance, you could say you were jesting, again)
 
Perhaps I can, and perhaps you can, but some people cannot forget names and price tags, and it can skew the results in their minds. Things like thinking: Hey, that sounds like a $300 amp, not like the $10k amp it is, but it's from a famous name manufacturer who is revered, so I must be wrong.
And that's pretty well it, Dejan. Most males need a hierarchy of authority, to feel comfortable in - the bloke on top of me can kick my head whenever he feels like it, and as compensation I get to kick the heads of those below me. Pretty simple, basic stuff - and it sort of works, except it's got a staggering number of people butchered for centuries, of course. And that mode of behaviour and thinking translates into every area, including hifi gear ...
 
The Best of Ophthalmology.....EyeWorld News Magazine ??

of course in the primitive phoropter scenario I remember short time switching, directed questions on literal focus or straightness.., ability to repeat trials, doctor repeating, backing up, branching the stimulus, tested lens combinations guided by a willing and cooperative subject reporting in a restricted sense domain that the procedure is well tuned too

very much an effective example of the some of the differences in audio and visual memory, processing, perceptual repeatability - they really aren't the same
 
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And ... ??

In fact, I have a very casual interest in the area of spectacles - I had to wear them when young, I was an absolutely ferocious reader in earlier days, and then one day I said, "Mum, the letters are all blurry ... "

Outgrew them when I got older, and to this day am still getting away with those cheap plastic things from the chemist. But, I have had periods when my eyesight started to play up, and by instinct I started to do various eye exercises, forcing the muscles to work harder - which worked! I still do this regularly, when my vision is getting tired - and it pulls my ability to see comfortably back in shape. IOW, by will, and focusing, you get the body to work a bit better than it would otherwise ...
 
And similar is a good test for a system: put on a piece of music you know absolutely nothing about; in a genre you don't particularly care for, or even object to normally; and wind up the volume. If you get straight away why the musicians are doing it, why they bothered to record the thing at all, what the buzz was for them - then the system is in a pretty good place ...
 
when in fact Visual Perception is one of the easiest fields to find Perceptual Illusions in, demonstrate that "perception" differs from the objective stimulus due to the visual systems lower processing layers

Sure, Hoffman's work is full of such examples - he bases much of his research on exploring how they occur. He has several up on his website. So it looks like, once again you're tilting at windmills.
 
And similar is a good test for a system: put on a piece of music you know absolutely nothing about; in a genre you don't particularly care for, or even object to normally; and wind up the volume. If you get straight away why the musicians are doing it, why they bothered to record the thing at all, what the buzz was for them - then the system is in a pretty good place ...
I've stated before that this will never happen. Nor will I tune in Dancing With The Stars to evaluate video, or fry some grasshoppers for dinner to season a new cast iron skillet. Call me obstinate.
 
There are several ways to listen effectively. The professional musicians approach is one. Once I lived in a hotel with 100+ classical musicians and was part of the 'staff'. We ate together, listened to live concerts together, even listened to concerts on the radio together. They never failed to amaze me what musical information they could get from a 'portable' radio! To me, it was an abbreviated performance of a famous orchestra, but for them, it seemed to be much more. They could get (and add) details that I could not have heard through the small speaker. I came to realize that they both got more from the limited info from the radio, and even enjoyed the performance more. I put it down to their 'filling in' what was missing, based on their musical experience and memory.
Me, no way! I heard the problems with the musical transmission system, including IM, limited bandwidth, etc.
Now, who is better equipped (psychologically) to design audio equipment? The musician who can make much from relatively little? Or the person who strives for more musical information from the source?
By the way, I married one of the classical musicians (a violinist) and she was the same, only overtly reacting when a very special violin was played live with us in the audience. She could also 'forgive' most musical sources. She was never my best judge for sound 'quality' with minutia. She could be happy (generally) with less.
 
I've stated before that this will never happen. Nor will I tune in Dancing With The Stars to evaluate video, or fry some grasshoppers for dinner to season a new cast iron skillet. Call me obstinate.
I think you've missed the point. When you listen to music that you're familiar with, that is of a type that you're predisposed to, then you are very "forgiving" of the system - your brain is skating over the top of all the rough edges, and you're extracting the "essence" of the music beautifully - and having a great time of the listening. However, when absolutely none of these "crutches" are available, you're flying blind in the listening, and are totally dependent on every tidbit of moment to moment sound to work out what's going on - that's when a competent system will rise head and shoulders above something lesser ...

You don't have to fall in love with what you hear - you may still think it's a trite bit of nonsense - but you "understand" what the musicians doing it are getting from the performing.
 
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