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Old 22nd May 2012, 10:50 PM   #71
Simon B is offline Simon B  United Kingdom
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Quote:
Originally Posted by RNMarsh View Post
.....For those who wont read the article....There is no money involved.......

Those who won't pay to read the article would be more accurate.

The fact that you took no fee does not mean that there is no money involved in reading it!

I'm sorry to be pointing this out to you. I know that you do a great deal for this forum; if you like, you're one of the good guys.

But despite its non-profit (which I can well believe) nature, Linear Audio is a commercial concern, albeit a small one. Non-profit does not mean non-commercial - I don't know how things are in the States, but not-for-profit limited companies are very common here in Britain.

The rules of the forum state that:

Quote:
The regular forums are non-commercial and should have no advertisements or overtly commercial threads or posts

The OP's initial post was, whether intentionally or otherwise, a teaser for a Linear Audio article, the schematic for which will not be posted here. It was an advertisement.

Rules that only apply to some, no matter how good or noble the some concerned, are never a good thing.

I strongly suggest that Linear Audio, by all accounts a deliberately better than average publication in this field be given its own section in the forum. I think this would benefit everyone.

Finally, I'd like to apologise to those whom I have undeservedly insulted or offended.

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Old 22nd May 2012, 10:59 PM   #72
SY is offline SY  United States
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Appreciate you looking out for the Forum's interest, but none of the staff here believe that this falls under our commercial rules.
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Old 22nd May 2012, 11:11 PM   #73
Simon B is offline Simon B  United Kingdom
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Originally Posted by SY View Post
Appreciate you looking out for the Forum's interest, but none of the staff here believe that this falls under our commercial rules.

Well, your opinions are those that hold sway, of course. Though I cannot agree with your interpretation of what to me is a very clearly written rule.
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Old 22nd May 2012, 11:29 PM   #74
SY is offline SY  United States
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I have the disadvantage, when interpreting it, of being the guy who wrote it.
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Old 23rd May 2012, 12:16 AM   #75
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I have the disadvantage, when interpreting it, of being the guy who wrote it.
Just 'cause you wrote it doesn't mean you can read it!

se
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Old 23rd May 2012, 12:19 AM   #76
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Originally Posted by Telstar View Post
I think at 20khz any soundcard AD has problems, but i'll gladly be corrected.

The distortion magnifier removes the dynamic range issues, come on guys bridge null tests are old school. Extracting distortion with the full scale stimulous present is just self abuse.
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Old 23rd May 2012, 12:29 AM   #77
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Originally Posted by RNMarsh View Post
I have built R.Cordell's distortion magnifier plus I use AP.
Me too, results? In the end I find the source nulling techniques to far exceeed the capabilities of brute force THD measurement. Somehow these techniques were denigrated by folks that used Hafler's version of them and did not find corellation to listening tests. Anecdotal, arbitrary, and unscientific.
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Old 23rd May 2012, 12:51 AM   #78
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I also have over a hundred MiT caps between Martin logan CLX and Dynaudio 7.1 home theater crossover rebuilds, as well tube electronics - PPFXS , RTX , and TFT 's .
I use RTX in solid state servos - are film and foil overkill for a servo?
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Old 23rd May 2012, 01:21 AM   #79
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by coluke View Post
Hi Richard, what about its output impedance? I'm working on an open-loop hp buffer/amplifier - actually a standard CF open-loop topology working very well indeed. My tests show that in order to avoid a dramatic THD raise at lf the output impedance must be kept extremely low. In my first prototype it was about 2.5 ohm, but now I'm managing to reduce it further to 0.1 ohm or so. Did you manage to measure THD on low Z (~ 30 ohm) * real * load?

L.
The thd in the article was quoted as into 30 Ohm load and it was well better than .001%. Higher load Z would give lower thd. A search on the Internet of headphone Z showed many were below what IC's could handle well... that is why I went for 30 Ohms for design goal.
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Old 23rd May 2012, 01:27 AM   #80
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by Simon B View Post

Those who won't pay to read the article would be more accurate.

The fact that you took no fee does not mean that there is no money involved in reading it!

I'm sorry to be pointing this out to you. I know that you do a great deal for this forum; if you like, you're one of the good guys.

But despite its non-profit (which I can well believe) nature, Linear Audio is a commercial concern, albeit a small one. Non-profit does not mean non-commercial - I don't know how things are in the States, but not-for-profit limited companies are very common here in Britain.

The rules of the forum state that:


The OP's initial post was, whether intentionally or otherwise, a teaser for a Linear Audio article, the schematic for which will not be posted here. It was an advertisement.

Rules that only apply to some, no matter how good or noble the some concerned, are never a good thing.

I strongly suggest that Linear Audio, by all accounts a deliberately better than average publication in this field be given its own section in the forum. I think this would benefit everyone.

Finally, I'd like to apologise to those whom I have undeservedly insulted or offended.

yes, it will cost you money and yes, the magazine might make a profit. I happen to enjoy the higher level of technology discussion there and hope others would also. I try to teach a little as I go and give away what I have learned from time to time. Just because WE love music and making/building it.
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