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Old 26th August 2011, 08:13 AM   #15381
BV is offline BV  Slovakia
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Quote:
yet if I ask him "make me an amplifier that sounds good"
To whom? You, me him, them..?? To all? Do You mean all peoples like only beer, or only wine? Or You want something like "beer wine" ? So use DSP, equalizer and mix and enhance sound acording Your personal taste. But it has nothing to do with reproduction..
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Old 26th August 2011, 08:19 AM   #15382
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Hi,

Quote:
Originally Posted by BV View Post
To whom? You, me him, them..?? To all? Do You mean all peoples like only beer, or only wine? Or You want something like "beer wine" ? So use DSP, equalizer and mix and enhance sound acording Your personal taste. But it has nothing to do with reproduction..
You illustrate my point.

Now let me ask you, would you want to make an Amplifier that "sounds bad", that is a significant minority, or more of potential customers will react to the sound of the Amplifier negative and not buy it?

Ciao T
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Old 26th August 2011, 08:42 AM   #15383
BV is offline BV  Slovakia
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I am making amplifiers. And I am trying to make it so, that it changes signal (yes, music is also only signal, and nothing special..) so little as i can do, in all respect (linearity, time domain..),and for reasonable price, so i prefer simple solutions(if possible) and do not like "unobtainium". For sure this "sound" will not be "good enough" for all, but for significant "minority" as You call it, yes. I am not trying to "improve" this signal according someones personal taste, and for sure not acording all peoples, it is impossible. I want let it as is.

Last edited by BV; 26th August 2011 at 08:47 AM.
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Old 26th August 2011, 08:44 AM   #15384
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Originally Posted by lvigone View Post
One of the main "disasters" for audio engineers, according to my view, is the Fourier Theorem; it's a quite complex argument, so it has attracted the interest of many. FFT tools and software are easily available today, so everybody use them and most of the discussion are based on their outputs.

But I don't believe they are really useful to understand the listening difference in the audio reproduction products. I stopped to use FFT as the main design tool, for my own diy realizations, from long time: it has been replaced by a good analog storage scope.

I want to highlight an interesting article come to my attention only today; inside it some discussions related to phase audibility are worthy of interest. It appeared on Audio magazine November 1961, nearly fifty year ago, but they are still very actual and neglected today!!
I completely agree with the theory of John Campbell (see my past posts): here the link Sineward distortion in High-Fidelity amplifiers.
Hmm. I need to read that article more in detail, but how can an amplifier turn a square wave into sines while having a flat amplitude response up to 70kHz??

jan didden
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Old 26th August 2011, 08:54 AM   #15385
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Originally Posted by SY View Post
Well, I'm pretty sure I heard the difference in those tracks despite not being a golden ear and using a 5 way speaker system. When Prof. Hawksford provides the key, I'll at least know if it's something I need to worry about. I hope that he's amused by some of the weird paranoia that has been exhibited about a simple listening test...
The key word being 'differences'. The question is not: 'which track has zero phase shift' or 'which track has +180 degrees at some frequency'. The question is simply: 'which ones sound different from some others', something experienced listeners are supposed to excel at. And it is assumed that the experienced listeners use the same (or better) speakers and/or headphones as we all do.

Coming back to the numbers; if there are 10 discrete different groupings possible, does that mean that the chances of getting it right by guessing are just 10%. And that when you get it right, you have a 90% confidence that you did that based on actually hearing a difference?

Some have asked about my own score: I came as far as identifying two files that I thought were clearly different from one other file. At that point, after trying for several evenings, I received other people's scores so that shot my objectivity.

About the paranoia: Malcolm mentioned that "everyone can be disappointed that i did not attempt to trick them".

jan didden
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Last edited by jan.didden; 26th August 2011 at 08:58 AM.
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Old 26th August 2011, 09:14 AM   #15386
SY is offline SY  United States
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Yes. 90% is not a terribly impressive confidence, but it's better than nothing.
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Old 26th August 2011, 09:16 AM   #15387
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Hi,

Quote:
Originally Posted by BV View Post
I am making amplifiers. And I am trying to make it so, that it changes signal (yes, music is also only signal, and nothing special..) so little as i can do, in all respect (linearity, time domain..),and for reasonable price, so i prefer simple solutions(if possible) and do not like "unobtainium".
Well, if the amplifier does not change the signal, then by definition it is "transparent".

If it does change the signal (which all known amplifiers do) and if you do not have access to extraordinary components (e.g. you need to use normal semiconductors or tubes etc.) you will have to make design choices that trade off performance in one area for a loss in another.

For example, I can make an amplifier that is unconditionally stable, has 120dB NFB at DC and very low measured THD at 1KHz. By having done this however there is a good chance that I have worsened some other performance parameters and elevated some forms of distortion normally well below the noisefloor to prominence, plus these distortions may resist measurements using traditional steady state signals.

The end result is that I may have an amplifier I can point to my instrumentation as "changing the as little as possible" while it actually does provide quite reliably "bad sound". Where does that leave me?

How would you suggest we weigh the different dimensions of quality, what do we emphasis, what do we de-emphasise?

Ciao T

Last edited by ThorstenL; 26th August 2011 at 09:31 AM.
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Old 26th August 2011, 09:28 AM   #15388
Bonsai is offline Bonsai  Taiwan
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Quote:
Originally Posted by ThorstenL
For example, I can make an amplifier that unconditionally stable, has 120dB NFB at DC and very low measured THD at 1KHz. By having done this however there is a good chance that I have worsened some other performance parameters and elevated some forms of distortion normally well below the noisefloor to prominence, plus these distortions may resist measurements using traditional steady state signals.
You can also do all of these things, and have an amplifier that also sounds very good.
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Old 26th August 2011, 02:03 PM   #15389
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Originally Posted by Bonsai View Post
You can also do all of these things, and have an amplifier that also sounds very good.
Yet there are those here, that will state out of hand that such an amplifier can't sound good.
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Old 26th August 2011, 02:15 PM   #15390
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Hi,

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Originally Posted by scott wurcer View Post
Yet there are those here, that will state out of hand that such an amplifier can't sound good.
And those, who like myself will state that from the given specifications it is not possible to conclude anything about the subjective sound quality of the Amplifier.

Ciao T
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