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Old 7th May 2013, 05:31 PM   #341
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My expectations are still rather high. Got some RO65's here I might throw in a ACA style amp with LTP FE. See what Mike's articles can help me achieve. Learning is the fun part.
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Old 7th May 2013, 07:49 PM   #342
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Intelligence MeBad...
Anyway, don't mean to be insulting... That has just been the way this area of the industry/hobby etc. has been and I don't expect meraculous discoveries that uncover the electronic/hearing mystery any time soon. But, I'm open
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Old 30th March 2014, 10:01 PM   #343
aoc is online now aoc  Malaysia
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Semisouthfan,
When is Whats the Buzz part 2 coming out?

Alex
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Old 27th April 2014, 04:25 AM   #344
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Quote:
Originally Posted by Semisouthfan View Post
Buzz,

The second article, long in coming (sorry), is about distortion reduction from load-line canceling, and measurement and modeling methods to assist DIY'rs to estimate performance of SemiSouth JFETs (and other transistors) in amps.

I plan for a third article to be on other forms of negative feedback, with a particular look at source degeneration. From my analysis, for example, the 0.6 Ohm of Rs in an F2J contributes to THD reduction. It is likely that anything in the range you quote will make a difference.
Hi Mike,

Any news on Parts II and III of your article? btw, thoroughly enjoyed Part I.
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Old 1st May 2014, 01:50 PM   #345
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Do these power jfets also have lower distortion when used as a source follower ?
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Old 1st May 2014, 06:15 PM   #346
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Absolutely! Turning all available gain into "degenerate" feedback is a powerful linearisation tool. But the "sweet spot," according to Nelson's article on the matter, can be discerned in favor of the SemiSouth power jfet even when all of the competing transistor choices are operated as source or emitter followers as well. That's because, in my opinion, of the shape of the curves in the output characteristics which the SemiSouth power jfets have unique to themselves.

But that is the subject of Part II, which is way overdue, but mostly written. Sorry all you patient souls!!

I owe, I owe, it's off to work I go...

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Do these power jfets also have lower distortion when used as a source follower ?
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Old 1st May 2014, 08:04 PM   #347
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it's OK , you still have some credit not spent ......

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Old 1st May 2014, 11:46 PM   #348
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So what about this as an idea. Here we can minimize the dissipation of the jfet using the cascode fet, the same fet that we might otherwise use to regulate the B+ .
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Old 1st May 2014, 11:57 PM   #349
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so?
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Old 4th May 2014, 11:51 AM   #350
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Why I brought this up is using a cascode source follower we could squeeze 200 watts class A from one SJP120r100 true the cascode device will have to be HUGE.
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