final follower
The output signal is not taken from Drains of CG mosfets, but instead there is (mos)fet follower. Or I'm misinterpreting Mr. Curl's comment?
john curl said:
The output signal is not taken from Drains of CG mosfets, but instead there is (mos)fet follower. Or I'm misinterpreting Mr. Curl's comment?
Elso,
Thanks for your valuable comments. As I am not an expert, but an amateur trying to achieve a reasonable and stable circuit, I thought it would be a good idea to take this information to the forum for further discussion.
My individual goal is not to build a copy of the Blowtorch but to achieve a rocksolid circuit with as less as possible components in the signal-way. When that goal is reached I will implement my own re-structuring methods.
The first part of the servo schematic contains two separate opamps the following stage are, if I'm right (correct me if not) a summing and difference amp.
Maybe others more experienced may shed some light on this, but you are right that it needs further refinement/improvement.
Thanks for your valuable comments. As I am not an expert, but an amateur trying to achieve a reasonable and stable circuit, I thought it would be a good idea to take this information to the forum for further discussion.
My individual goal is not to build a copy of the Blowtorch but to achieve a rocksolid circuit with as less as possible components in the signal-way. When that goal is reached I will implement my own re-structuring methods.
The first part of the servo schematic contains two separate opamps the following stage are, if I'm right (correct me if not) a summing and difference amp.
Maybe others more experienced may shed some light on this, but you are right that it needs further refinement/improvement.
Servos
Hi courage, no problem discussing here.
As you might know I don't like servos. I clipped them out of my Ampzilla.... On the other the circuit will probably not work without servo......
Walt Jung publised some servos in his booklet Audio IC Op-Amp Applications. That were the servos I tried in my phono stage. These were 1-stage servos. Obviously you need 2-stage servos.
Foe a simple servo see f.a :
http://www.johnhardyco.com/pdf/990.pdf
and:
http://headwize.com/projects/showproj.php?file=gilmore3_prj.htm
http://www.ibiblio.org/tkan/audio/dynahi/dynahi_amp_sch.png
😎
Hi courage, no problem discussing here.
As you might know I don't like servos. I clipped them out of my Ampzilla.... On the other the circuit will probably not work without servo......
Walt Jung publised some servos in his booklet Audio IC Op-Amp Applications. That were the servos I tried in my phono stage. These were 1-stage servos. Obviously you need 2-stage servos.
Foe a simple servo see f.a :
http://www.johnhardyco.com/pdf/990.pdf
and:
http://headwize.com/projects/showproj.php?file=gilmore3_prj.htm
http://www.ibiblio.org/tkan/audio/dynahi/dynahi_amp_sch.png
😎
Hi Elso, you are right that the circuit needs a servo to perform well according to my simulations. Thanks for the link to some more info.
Estman:
All information and schematics I have come across have the output taken from the Drains. If that was not the case John would have pointed that out.
Off topic: How do I get the quote from a poster with his name mentioned? Now I click on the "Quote" button and insert my copied text. Thanks in advance for explaining.
All information and schematics I have come across have the output taken from the Drains. If that was not the case John would have pointed that out.
Off topic: How do I get the quote from a poster with his name mentioned? Now I click on the "Quote" button and insert my copied text. Thanks in advance for explaining.
courage said:
In your reply do not delete text:
(QUOTE)Originally posted by ***** (/i).
Only edit his post, if needed, between (B) and (/B)(/QUOTE).
John, thanks for your encouraging remark. I think now there's plenty of room to get the discussion up and going on the basis of presented schematics.
What can be improved in either schematic? How about the servo, which as the frequency plot shows, needs improvement/refinement?
So, let the fun part begin 😉
OK, Captain Sou(s)-Cegarou.
How about a CCS again instead of the 200s.
And what about placing 2 FETS in parallel, out of the question ?
(instead of the 76/213s)
How about a CCS again instead of the 200s.
And what about placing 2 FETS in parallel, out of the question ?
(instead of the 76/213s)
Hello Sjaco 😉
My aim is to stay as close as possible to the BT and as can be seen this is a minimalistic approach. Your proposals involve more components. It depends on your personal preferences however. Of course you are free to alter the design to your liking.
My aim is to stay as close as possible to the BT and as can be seen this is a minimalistic approach. Your proposals involve more components. It depends on your personal preferences however. Of course you are free to alter the design to your liking.
and then:
but earlier (post #776)
john curl said:
Someone could buy one and reverse engineer it the easy way!!!!! or maybe a group buy and share the reverse engineering 😉 or maybe someone could just build something something and listen and tweak, and listen, and .... speaking of which back to the protoboard 😎
Bill
who really doesn't like the smilies but is making an effort and hopes they help convey the spirit of the post.
Group Buy
I we collect 100 group buyers each has to donate only $ 150.
Then we can reverse engineer the unit and sell on Ebay or Audiogon and pay back the funds to each one of you. Deal?
Suppose we sell the unit for $10,000 so each gets back $ 100.
In the end the price for reverse engineering is thus $ 50, a bargain.
😀
I we collect 100 group buyers each has to donate only $ 150.
Then we can reverse engineer the unit and sell on Ebay or Audiogon and pay back the funds to each one of you. Deal?
Suppose we sell the unit for $10,000 so each gets back $ 100.
In the end the price for reverse engineering is thus $ 50, a bargain.
😀
Good Promotion
This whole thread is Upupa!
But I seriously doubt ANY potential buyer of the Blow Torch will read this thread!! So.....?
😎
🙂
Upupa Epops said:
This whole thread is Upupa!
But I seriously doubt ANY potential buyer of the Blow Torch will read this thread!! So.....?
😎
🙂
Burros and Clever Guys
Upupa, I don't copy. I designed my own phono and line stage that are way more complicated and have no servo! No 2SK389/2SJ109 either.
I am just helping some friends here and off line too.
If and when I have collected the $ 15.000 guess what I am going to do.....
Upupa Epops said:
Upupa, I don't copy. I designed my own phono and line stage that are way more complicated and have no servo! No 2SK389/2SJ109 either.
I am just helping some friends here and off line too.
If and when I have collected the $ 15.000 guess what I am going to do.....
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