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John Curl's Blowtorch preamplifier part II
John Curl's Blowtorch preamplifier part II
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Old 27th November 2012, 07:56 PM   #30091
Esperado is offline Esperado  France
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Originally Posted by jneutron View Post
I consider soundstage and performance (not artist, but system) to be realism. I want to close my eyes and touch the artist.
I too, specially when the singer is a very pretty girl :-)
 
Old 27th November 2012, 07:56 PM   #30092
jneutron is offline jneutron  United States
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Originally Posted by Kindhornman View Post
JN,
Now I understand what you are looking at. A modulated inductance caused by the moving voice-coil in the gap. This is one of the reasons that I use a very long gap with a short voice-coil as the voice-coil sees the same magnetic energy throughout its travel. One of the reasons in a cone loudspeaker I would never use an under-hung coil or an equal length coil and gap, both of these types of devices are nonlinear in design, no way around that factor. And another thing is that I do use a copper sleeve to smooth eddy currents in the magnetic motor.
Yes.

For static systems, the voltage at the terminals is e = L di/dt. For dynamic systems, the voltage is e = L di/dt + i dL/dt.

When a current is present in a moving VC, the iron or copper will fight change of flux (lenz effect), lowing inductance and increasing Rs. A moving VC will appear to have lower inductance because of this. How much, no clue..

THAT's where speaker designers come in...

jn
 
Old 27th November 2012, 08:00 PM   #30093
PMA is offline PMA  Europe
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Though it may sound as a nonsense, we have to consider speaker cables as distributed parameters. For induced interference, at least.
 
Old 27th November 2012, 08:04 PM   #30094
Joshua_G is offline Joshua_G  Israel
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Originally Posted by Esperado View Post
Did i wrote that ?
No, you didn't write it explicitly, however it is what I got from what you wrote.

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I'm interested about what you call *realism* when i produced records.
Good to see it.
Is there any possible difference between what you call realism and between what I call realism?

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And was payed for that ability and talent to create that kind of make believe. Dot.
Is music realism a make believe, to your view?

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Originally Posted by Esperado View Post
When it is about reproduction, i want fidelity. Carbon copy. Not at all the same thing.
What do you call "carbon copy", what do you call "music realism" and what's the difference between the two?

Possibly, you and me attach different meaning to certain words and expressions.
 
Old 27th November 2012, 08:10 PM   #30095
Joshua_G is offline Joshua_G  Israel
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Originally Posted by Esperado View Post
Musicians comes one after the others in a more and more little studio, and engineers try to create a realistic make believe the where all playing together in a big hall stage.
To my view, this is adding some artifacts. It has nothing to do with actual music realism.

I have many recordings recorded at concert halls. No all of those recordings have the same amount of music realism. Thus, music realism isn't about artificial attempts at creating a sense of a concert hall.
 
Old 27th November 2012, 08:15 PM   #30096
Joshua_G is offline Joshua_G  Israel
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Originally Posted by PMA View Post
In fact we have to "subtract" (reduce, filter) interference noise. From power supplies, cable interconnects and EMI/RFI. This is not any addition, but cleaning.
Indeed, however we need to attempt at adding as little as possible and subtracting as little as possible to the audio signal itself. By adding as little as possible means not only THD and IMD.
 
Old 27th November 2012, 08:21 PM   #30097
RNMarsh is offline RNMarsh  United States
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John Curl's Blowtorch preamplifier part II
Default AC line interference eliminated -

I decided to put my TEK scope with FFT option (FFT to 300MHz) on the thd analyzer residual output and there was a large freq at 305KHz. After some exploring for its source, it was coming from an iPOD Classic plugged into a speaker tower thingy that i use for background music in my testing room. It wasnt from the iPOD itself but the player/amp/spkr base. probably digital amp and/or power supply. It was the power supply -- when I put the distortion analyzer thru an ac power isolation-filter which i designed for Monster Products - it is now gone. Be careful to avoid EMI/RFI when testing, too. AC line interference gets into everything. THX-RNMarsh

Last edited by RNMarsh; 27th November 2012 at 08:27 PM.
 
Old 27th November 2012, 08:22 PM   #30098
gpapag is offline gpapag  Greece
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John Curl's Blowtorch preamplifier part II
Quote:
Originally Posted by john curl View Post
I have a Telefunken portable radio that I first bought in 1965, and used it, even today. I love it! Better than any Sony, etc I have ever tried.

Quote:
Originally Posted by Kindhornman View Post
JN,

…one of the reasons that I use a very long gap with a short voice-coil as the voice-coil sees the same magnetic energy throughout its travel. One of the reasons in a cone loudspeaker I would never use an under-hung coil or an equal length coil and gap, both of these types of devices are nonlinear in design, no way around that factor
.
Steven, please have a good look on pages 28 to 33 especially fig. 24,25,26 on Mr. Klippel’s paper.

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OK George, AND?
Not OK. Did you read them that fast Mr. Curl? At least you should take note of IMD % figures on pages 46 to 64 of Mr. Klippel and I am afraid all pages of Ms. Thuras, Jenkins, O’Neil )

OR they are non relevant to "REAL WORLD Audio"?

George
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Old 27th November 2012, 08:25 PM   #30099
Esperado is offline Esperado  France
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Originally Posted by Joshua_G View Post
Is music realism a make believe, to your view?
Absolutely.
And the best ways to create this realistic make believe require often very unrealistic recording methods. Close miking, use of many effects and frequency corrections, artificial reverberations etc.

If you are talking about live recordings of classical music concerts with a couple of microphone, im' no more in concern, and i found never those recordings as "realists".
Because, when i'm in a concert hall, my brain do all his possible to get rid of ambiance of the hall and concentrate on the instruments i never hear close enough.

But our discussion was about digital equipment, and i was just pretending that you can have top transparent parts, using good consumer products, reclocking, filtering power supplies for no noise and using good DAC and good following analog stage, with no need of "Golden Pinnae" mysterious devices and transports.
Transparent, i mean no audible added distortion, no losses of details, no tonal change, no added sparkles. Nothing you can distinguish from an other similar device in a noticeable way with blind listening.
If one thing is reassuring, in the digital domain, it is that all is measurable (samples). I hoped we could, at least, get rid of all this cloudy voodoo audiophile magic.

But no. Some try to bring-it back ?

Last edited by Esperado; 27th November 2012 at 08:34 PM.
 
Old 27th November 2012, 08:31 PM   #30100
Joshua_G is offline Joshua_G  Israel
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Originally Posted by jneutron View Post
Concur. What adding was meant to convey was changing..modification. To me, the word transparent means to not alter in any fashion.
An ideal recording/mixing setup and reproducing setup would be 100% transparent.
Practically, in our present universe, no recording/mixing setup and no reproducing setup is 100% transparent.
Therefore, the whole process of recording and the whole process of reproducing involve compromises.

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Originally Posted by jneutron View Post
Systems which measure the same should sound the same.
Ideally, it should be so.

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Originally Posted by jneutron View Post
Unfortunately, bench measures are not in situ measures.
Indeed. Therefore, at present, we cannot choose audio gear based on measurements alone.

Quote:
Originally Posted by jneutron View Post
I consider soundstage and performance (not artist, but system) to be realism. I want to close my eyes and touch the artist.
Soundstage performance is only one aspect of music realism.
Since I listen mostly to classical symphonic music, there is no way that in my tiny living room a soundstage the size of a concert hall will be reproduced.

There is no sound reproducing setup in the world, at any cost, that can reproduce live music with perfect fidelity. By perfect fidelity I mean that a trained professional musician, one who cares about the sound of the instrument one is playing, will enter a room with ones' eyes blindfolded, and will mistake a reproduced music to be a live concert.

Therefore, compromises are unavoidable. Some people don't care at all about any proximity to live concert. Out of those people who do care about it, to various people, various aspects of live music are more important. Hence personal taste and preferences.
 

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