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.
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 😀
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 😀
Hi Mike,
Any news on Parts II and III of your article? btw, thoroughly enjoyed Part I.
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...
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...
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.
You can get huge cascode devices, or you can parallel some devices with
ballast resistors for current sharing.
😎
ballast resistors for current sharing.
😎
Nelson in this type of application would you expect a power Jfet used as a folower to
have significantly lower distortion and used as a follower the input capacitance won't be
a problem to drive ( as you mentioned in your mosfet citation 12 article )
have significantly lower distortion and used as a follower the input capacitance won't be
a problem to drive ( as you mentioned in your mosfet citation 12 article )
It should also help improve the open loop bandwidth if memory serves me right
Alex
Sent from my C6903 using Tapatalk 2
Alex
Sent from my C6903 using Tapatalk 2
I don't expect that there would be any issues. As followers, almost everything
we play with is easily driven from a capacitance standpoint. The rationale
for cascoding the follower is to take dissipation off the part so that you
can bias it at high levels.
😎
we play with is easily driven from a capacitance standpoint. The rationale
for cascoding the follower is to take dissipation off the part so that you
can bias it at high levels.
😎
Nelson,
I believe you've also noted elsewhere that followers exhibit less distortion if ran under cascode. Is that because of the increased bias current, or lower voltage across the device?
I believe you've also noted elsewhere that followers exhibit less distortion if ran under cascode. Is that because of the increased bias current, or lower voltage across the device?
What's the Buzz - Part II
Attached is the second part in a three part series entitled "What's the Buzz?" The document and a supporting spreadsheet are included in the zip archive. I had to reduce the resolution of the pdf document to fit under the upload file size limit imposed by the forum. If you prefer slightly better resolution, email me and maybe I can arrange for the higher rez document to be available on a file uploader site.
Many of you have encouraged me throughout the more than one year it has taken me to research and write the second installment. Well! I"m glad to finally be able to push the post button and get this off my chest. It's like a good confession, it really puts the mind at ease.
Anyway, as before, this is the next step in my goal to understand why you guys like the SemiSouth JFET so much.
As before, I hope you find it both worthwhile and entertaining to read. The subject of Part III, negative feedback, is hardly a topic calculated to get the next one out in a timely manner, but your encouragement does really help.
Attached is the second part in a three part series entitled "What's the Buzz?" The document and a supporting spreadsheet are included in the zip archive. I had to reduce the resolution of the pdf document to fit under the upload file size limit imposed by the forum. If you prefer slightly better resolution, email me and maybe I can arrange for the higher rez document to be available on a file uploader site.
Many of you have encouraged me throughout the more than one year it has taken me to research and write the second installment. Well! I"m glad to finally be able to push the post button and get this off my chest. It's like a good confession, it really puts the mind at ease.
Anyway, as before, this is the next step in my goal to understand why you guys like the SemiSouth JFET so much.
As before, I hope you find it both worthwhile and entertaining to read. The subject of Part III, negative feedback, is hardly a topic calculated to get the next one out in a timely manner, but your encouragement does really help.
Awesome!
SemiSouthfan,
I/we really appreciate you taking the time to put this together. I'm looking forward to learning from it. Part I was excellent.
I keep hoping the products will get re-released at some point. I think the demand would be there.
Thanks again,
Steve
SemiSouthfan,
I/we really appreciate you taking the time to put this together. I'm looking forward to learning from it. Part I was excellent.
I keep hoping the products will get re-released at some point. I think the demand would be there.
Thanks again,
Steve
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