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Old 3rd November 2012, 06:42 PM   #28871
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Originally Posted by gedlee View Post
I do not think that a lens is a good comparison. Chromatic aberation is comparable to frequency response aberation, but that's about all.
Chromatic aberration is just a difference of deviation angle in regard with wave lenghs.
Like in a prism.
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HOMs are created when the boundaries of the device deviate from those that allow a spherical wavefront to develope. There is precisely one boundary that allows for the developement of a spherical wavefront from a flat circular source and that is the OS.
That is when the walls of the horn are perpendicular all the way to the wave front, i presume ?
So, there is a shape that will produce no or little of those HOMs. And designing horns for pseudo spherical waves (depending on the driver) was not a stupid idea... I will try, one of these days, to build a horn with silicon on the first centimeters of the throat, like in human ears, to see if any added damping...
Well, at the end, i can understand the effects on those HOMs on spatial response curves, not on distortions, if air non linearity is not an issue.

Happy to know that comparing distortion and spacial frequency responses curves is enough to evaluate horns. My nights were full of HOMs nightmares. (smiley here)

Thanks for your explanations, Mr. Gedlee.
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Old 3rd November 2012, 06:46 PM   #28872
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Originally Posted by Esperado View Post
I use symmetric cables, and the shields are connected only source side (no current).
I think you mean balanced/differential cables? In this case I too would lift the shield at receiver side, like it is done in studios.

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Originally Posted by Esperado View Post
Toroidal transformers are not the best regarding this problem of AC leakages.
Maybe because of higher parasitic capacitance between windings. I like the R-Core types, but they are expensive above 100VA.

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Old 3rd November 2012, 07:10 PM   #28873
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Esperado, the amp schematic at your web page doesn´t show the IN- input, how do you do it?

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Old 3rd November 2012, 07:16 PM   #28874
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Originally Posted by Alexandre View Post
I think you mean balanced/differential cables? In this case I too would lift the shield at receiver side, like it is done in studios.
In studios it is done usually after failed attempts to find guilty part in mixed symmetrical and asymmetrical interconnects.
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Old 3rd November 2012, 07:26 PM   #28875
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Who is a genius?

Marilyn vos Savant - certified by the Guiness Book of World records has the highest recorded IQ of any living person. But, never inspired a new genre in any field. Many exceptional achievers do not attain genius-level IQs. W. Shockley had an IQ well below 140. But, B.Pascal IQ was in the 180's. So, IQ is not the best indicator of genius.

Genius goes to those who produce original and exemplary accomplishments.

Interesting research on creativity -Scientific American Mind: Think Like a Genius. How exceptional intelligence and creativity arise. Nov/Dec 2012.
I would think that at the extremes the tests would have huge error bars because we simply don't understand.
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Old 3rd November 2012, 07:35 PM   #28876
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Originally Posted by Wavebourn View Post
In studios it is done usually after failed attempts to find guilty part in mixed symmetrical and asymmetrical interconnects.
Maybe it should be done this way by design. I have seen this recommendation in a console installation manual. They recommended a true star ground, with all interconnects balanced and the ground connections being through the AC outlets only.

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alex
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Old 3rd November 2012, 08:30 PM   #28877
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Originally Posted by Alexandre View Post
Esperado, the amp schematic at your web page doesn´t show the IN- input, how do you do it?
Current-feedback, but you can leave the original differential stage - input for quasi symmetrical input, and improve CMR and PSRR.
(Wolfman jack's voice: "Yeah, man, i used two acronyms !")
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Old 3rd November 2012, 08:37 PM   #28878
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W. Shockley
I once heard from a professor that the true inventors of the transistor were Bardeen and Brattain, with Shockley entering later as the project supervisor. And that they weren´t too happy when Shockley took the lead for the famous picture:

Click the image to open in full size.

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alex
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Old 3rd November 2012, 10:18 PM   #28879
bcarso is offline bcarso  United States
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Quote:
Originally Posted by Alexandre View Post
I once heard from a professor that the true inventors of the transistor were Bardeen and Brattain, with Shockley entering later as the project supervisor. And that they weren´t too happy when Shockley took the lead for the famous picture:

Click the image to open in full size.

thx
alex
Shockley was a clever and complex character, quite a promoter. Anyone in here old enough to remember his four-layer diodes? I mean, besides me And then he associated himself with the genius sperm bank stuff, hilariously parodied on Saturday Night Live when Rodney Dangerfield hosted.

Bardeen was amazingly bright and insightful, apparently rather self-effacing, and is the B of the BCS theory of superconductivity. To date he remains the only double-Nobelist in the field of physics.
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Old 4th November 2012, 12:19 AM   #28880
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Is these Ego problems had let traces in Silicon able to explain those disparities and non linearities against which we still have to fight today ?
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