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Old 28th September 2005, 07:26 AM   #11
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Ha!

Finessing amplifiers is the art within the science - but the science must be right first!



Cheers,
greg
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Old 28th September 2005, 08:05 AM   #12
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Now you're discussing psychoacoustics, and there's precious little that's known about that. Even as long ago as the early 1960s it was demonstrated that people could easily be "trained" to prefer the sound of deliberately horrible amps, and to judge that one "better" than a really good one. Now, you take that guy who's been listening to a SET for the past ten years, give him that theoretical "wire with gain", and you know he's going to wonder why his music doesn't sound "right".

Furthermore, there is evidence that factors long overlooked are important, including what were once considered "ultrasonics", and subtle information "lost" under the noise floor. Nor is all distortion created "equal", and it's not necessarily a bad thing. After all, if it was, then you wouldn't include tone controls. Turn up the bass (or treble) and what comes out is no longer the same as what went in: i.e. it's distorted. Now Doug Self published a long polemic against B. Ollsen and the quasi-comp topology. Self had all the numbers to back up his claims against Ollsen. However, I've built them both ways, and Ollsen was right: quasi-comp sounds better AFAIC.

This whole business is going to be more art than science for the foreseeable future.

And that quest for audio nirvana is going to make a lot of people a lot of $$$$$, both from legitimate endeavours, and from $500 Volume Control Knobs.
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Old 28th September 2005, 08:10 AM   #13
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Yes, I agree, quasi comp can be made to sound better.

The straight wire with gain is a wonderful goal. But so often it presents as the straight wire with grain, despite very low measured distortion.

This is psychoacoustics, and the reason almost anything goes.....

Cheers,

Hugh
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Old 28th September 2005, 08:59 AM   #14
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Quote:
Originally posted by AKSA


The straight wire with gain is a wonderful goal. But so often it presents as the straight wire with grain, despite very low measured distortion.

This is psychoacoustics, and the reason almost anything goes.....

Cheers,

Hugh
The reason is not low distortion, but different design flaws. Low distortion does not necessarilly mean grainy sound, though it may happen.

We should find a reliable method to evaluate dynamic spectrum rather than FFT + averaging above steady state signals. This does not say much.

Every time when speaking about low distortion let's not forget we must not allow high order distortion even at very low amplitude levels and newly created high order distortion components. On the other hand, there is no reason to try to reduce H2 to -140dB , and having H11 = -100dB.
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Old 28th September 2005, 10:56 AM   #15
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Indeed, Pavel,

I agree emphatically with your comments......

A better metric? You have one?

Cheers,

Hugh
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Old 28th September 2005, 11:26 AM   #16
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Default Music is harmony, produced by humans to humans apreciation.

When one person evaluates...feeling the music with his sensors...ears...electrical to chemical transducers and brain recognizing music.... subjective evaluation can be translated in some human noises called speach.

Of course, there are objective values human created...and those values, Mathematics values and Mathematics expressions are another good formula of communication....signs in place of music..to evaluate music...interesting...not a direct formula...but can produce some results too.

The result we use to see, is that objective evaluations are matter of ethernal discussions, and i could not find conclusion nowhere....if some conclusion was found...show me the link to read...and thanks in advance by your kindness to show me this.

I am talking about a forum thread...that had more than 12 visitors, and unless 12 giving their opinnions...show me when majority agreed over numbers...i could see agreement related sonics subjective evaluation only.

But maybe i have searched in the wrong places, of course this is possible.

But, there are many times, that, despite all human differences in musical tastes....preferences of instruments, culture differences (Culture here as people characteristic...not knowledge quantity)... i could see that there are many moments that humans agree.

Maybe because direct communication is more clear...despite the Mathematics precision, the ones use those formulas are always discussing, disagreeing...so...nothing positive result...only doubts.

there are many that agree that JLH is good, despite distortions, despite this, that or those...so.... subjective evaluations, unless result in more positive communication, and could produce for us one reference of quality...one standard that allows our communication....better than...equal them...worst them.

When IMD...transient...clipping, harmonics are beeing already discussed...and now there are difficulties to find some point of agreement.....another metric can be a good idea.

By example, the study of human perception to increase the subjective evaluation...more direct....sound to humans.....in the place of sound to numbers and numbers to humans.

regards,

Carlos
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Old 28th September 2005, 11:34 AM   #17
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Quote:
Originally posted by darkfenriz
Most oeple hate family movies, they prefer hard porno
they don't like sweet ballads, they listen to black metal
neither like snooker or bridge or golf, rather rugby or boxing.
How about amplifiers?
Guess i am only different when it comes to amplifiers, for the rest i am soooo average.
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Old 28th September 2005, 11:59 AM   #18
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Quote:
Originally posted by AKSA
Indeed, Pavel,

I agree emphatically with your comments......

A better metric? You have one?

Cheers,

Hugh
Trying hard to find any twinkle , better say trying to find alternative design approach.

Regards,

Pavel
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Old 28th September 2005, 01:24 PM   #19
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Quote:
One of the things that sends shivers up the spine of a person like this is the sound of a musician's fingers rubbing over round wound strings as he positions his hand for the next note.
Grey, that is exactly what happens With oscilating amp, the finger movement in the classic guitar's string becomes sooo obvious, when the amp is made to be stable/no oscilation at all, that sound become very faint, hardly noticeable. I see in scope, the oscilation is about 15Mhz, the guitar's sound is certainly below 20khz. The question is, why the 15Mhz oscilation can make signals below 20khz tobe "super detailed"? What is the explenation?

This fact of having a "background" noisefloor can "boost" the details, is this the same case with Phono player system?

Audio maniacs hear the phono gives more detail, more "right" music compared to CD. But when there is "silince" between tracks, the phono is not quiet at all, it has low frequency hiss.

Is that the "more details" of phono plate comes because it has that very big noise-floor / all the time low frequency hiss?

Anyone has tried an experiment that if we "paste" the music program with a certain frequency test tone, will it reveal more detail to the music?

Hi Darkfenriz,

Some also enjoy something in between, not the hard ones, not the plain ones , but the "semi" ones
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Old 28th September 2005, 01:36 PM   #20
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Quote:
Originally posted by lumanauw


The question is, why the 15Mhz oscilation can make signals below 20khz tobe "super detailed"? What is the explenation?

The explanation is supersimple: following non-linear solid state devices will detect and intermodulate. This is nothing good, a kind of alchemy. Yes, distortion emphasizes details. This kind of emphasizing should be strongly avoided.
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