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Old 14th December 2012, 01:40 AM   #31411
RNMarsh is offline RNMarsh  United States
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If the thd/Im is below hearing threshold, very low noise and wide bandwidth etc by following either/any fashion design principle... why wouldn't the one with the fewest parts be preferred? -Thx RNMarsh
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Old 14th December 2012, 01:43 AM   #31412
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Originally Posted by RNMarsh View Post
yes it is. But --- you get low thd+n that way also. -RNMarsh
No, better results come from massive feedback architectures. There is nothing technical to support these low GNFB circuits are better.
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Old 14th December 2012, 01:51 AM   #31413
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... why wouldn't the one with the fewest parts be preferred? -Thx RNMarsh
Yes, why pray tell? Why not the most parts? Or maybe this is not a parameter that matters.
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Old 14th December 2012, 02:11 AM   #31414
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Originally Posted by a.wayne View Post
i can hear JC interpretation anytime i wish, it's available
Wayne, which of JC's illustrious designs do you have?

You need zillion V/us to do well in the Quan PIM test. One day, JC will conduct Quan on Blowtorch and we'll see how a truly 'hand carved from solid Unobtainium by virgins' product performs.

If we're REALLY lucky, we might be able to see the results of a Blind Listening Test of this against an evil 4558 device too.

In the meantime, JC has some Hirata test results on Blowtorch.
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Old 14th December 2012, 02:16 AM   #31415
wahab is offline wahab  Algeria
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Originally Posted by bcarso View Post

The voltage range is refreshingly large for this fast a part as well.

Since the open-loop gain is only about 80dB we would not expect the frequency-dependent nonlinearities to be much further reduced with global feedback below the -3dB frequency, and if we want much gain we will have to live with more distortion. But still in all, a nice part. And the voltage noise corner is not too high.
Assuming the 1K load , H2 amplitude curve keep flattening below 1Mhz
to the point that i would be surprised if it managed to reach the -90dB
mark at 10Khz , not counting that it s with a paltry 2V PP output level.

All in all , and despite an impressive slew rate , it will be undoubtly
outperformed at audio frequencies even by an old school 5534 linearity wise.
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Old 14th December 2012, 02:17 AM   #31416
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No, better results come from massive feedback architectures.
With high slew rates, it is my opinion too.
With transparent devices, better to use specialized ones, one with low noise, gain and little out current, followed by one with little gain and big current for output drive.
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Last edited by Esperado; 14th December 2012 at 02:33 AM.
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Old 14th December 2012, 02:21 AM   #31417
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Originally Posted by wahab View Post
All in all , and despite an impressive slew rate , it will be undoubtly outperformed at audio frequencies even by an old school 5534 linearity wise.
Why do not listen to -it, as i have done ?
5534 is a bad sounding OPA, on my taste.
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Last edited by Esperado; 14th December 2012 at 02:24 AM.
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Old 14th December 2012, 02:28 AM   #31418
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We outgrew the 5534 more than 30 years ago. We made hybrids by substituting a jfet pair for the 5535 input stage and sold them to Wilson Audio for their performance EQ ckts.
It was established then that it was worth the effort to do so. So many here lack quality experience.
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Old 14th December 2012, 02:43 AM   #31419
RNMarsh is offline RNMarsh  United States
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Default what context?

Quote:
Originally Posted by scott wurcer View Post
Yes, why pray tell? Why not the most parts? Or maybe this is not a parameter that matters.
Yes, I keep forgetting that this isnt really a Do-It-Yourself forum/site to build things. What constructor would care that it takes 40 transistors and more associated parts to get two channels of sound working. My bad. -RNMarsh

Last edited by RNMarsh; 14th December 2012 at 02:52 AM.
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Old 14th December 2012, 02:43 AM   #31420
wahab is offline wahab  Algeria
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Originally Posted by Esperado View Post
Why do not listen to -it, as i have done ?
5534 is a bad sounding OPA, on my taste.
For decades it sounded very good for many ears that currently
find it "bad sounding"...

It s not like ears were upgraded like an AP1--->AP2 over 30 years.....
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