Although i have an old Roman name, if you translate it into my native language it means "little Devil" 😉
Cool! My first own bought amplifier was the Sentec SC-8/PA-8 combo. I was maybe 13 yo and my father made me move the lawn as I came home with the kit. It was to be assembled by the owner. I was angry with him for days 🙂 I managed to fark up and used a long screw on the backside which reached the board and shorted the V+ supply - fuse broke. Had to go to store on Monday. Drove a set of JBL 2110 and 077 to nice levels to my parents undivided joy. Good memorys.
🙂
//
Why is that important? If your amp's BW changes with the gain set, it is likely operating as VFA.... no matter where the fb is applied.
-RNM
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Because I’m trying to figure out your definition of “CMA”. Although I suspect it’s a waste of time...
So you agree the H-bridge amplifier is a VFA? CMA is a meaningless term akin to TIM to describe already known large signal BW limitations as posted today described completely by 1970. BTW by the definition here all amplifiers are CMA, you have a transconductance at the input, voltage in gives current out.
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Why? You forgot one detail I pointed out yesterday, designing an amplifier for a fixed application the designer has the freedom to change the compensation to suit the closed loop gain and now the BW does not change.
Dreamth, I don't know what criticism of Doug Self that you are talking about. I debated Doug Self about 35 years ago in WW and HFN about cap quality, but generally I have ignored him. Can you give me a reference?
I thought i could swear that i saw a long article where you attacked him on his ne5534 quotes telling how great the fet transistors are instead...If i'm wrong please accept my apologies!
Chapter 3.1, page 27 here:
http://jockohomo.net/data/johncurl-v.0.1.pdf
Maybe i overreacted, I'd better read your article again.
PS: i saw smth at page 46 too...but it's milder than what i remembered.Most probably i just associated you with some others who spoke in contempt about D Self, given the fact that many people use his books for witchcraft...
Chapter 3.1, page 27 here:
http://jockohomo.net/data/johncurl-v.0.1.pdf
Maybe i overreacted, I'd better read your article again.
PS: i saw smth at page 46 too...but it's milder than what i remembered.Most probably i just associated you with some others who spoke in contempt about D Self, given the fact that many people use his books for witchcraft...
Except Ron Quan himself measured no PIM at all on the 797 or any number of modern op-amps (plenty on those old valve designs). The 797 bears not even the least similarity to the 5534 BTW, well it has an input and an output. That is an insult, Jocco actually saved this stuff I thought he was smarter than that ???
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Well...I couldn't find everybody too agree with JC on NE5534...We still measure with AP1 on ne5534...AD797 is just another type of op-amp used in AP2, with lower voltage noise and 5 times higher current noise and a very small input impedance compared to ne5534 , but maybe the closed loop savs it.
Siliconix made an application note on how to change with j-fets the input stage similar with lm318 , TI improved the 40 years old NE5534 and today's ne5534 at 0.5 bucks measures better than opa2134 (i've seen it with my own eyes) .It may not sound better because it doesn't have the even harmonic content of OPA2134, but who cares when most of the recordings until 2000 were made on ne5534?
For me, praising unobtanium complementary fet sounds like an easy way out. I appreciate you both for your achievement and professional career, but i wouldn't say that any op-amp is just useless for high end audio and only discrete stages can do it.Today's recordings are done exclusively on op-amps and digital equipment.
You probably sold lots of amplifiers to guys listening on a Nakamichi Dragon deck equiped with TL072 (D.self talks about that too, some of the best valve guitar preamps use it after 5 valves at the output) and i have no idea why would be all the world divided in such a way just because you sold some very expensive equiment to some very rich guys while most of the people couldn't afford an opinion.
D.Self praises too discrete design and actually shows some very performant bipolar stages with stunning performance in his books.Why would you just attack each other this way?Is it just because he made a technical evaluation on op amps after measuring them?
He was one of the best designers at Cambridge Audio and Soundcraft...You were rivals but Soundcraft still makes some of the best recording consoles in the world after D.Self designs...
By the way..once i wanted to throw away a Soundcraft eq and a guitar player who is my friend and is also a very good musician and well known in my country wanted it and after 11 years he still have it among very expensive RME recording equipment.I wonder why...
Siliconix made an application note on how to change with j-fets the input stage similar with lm318 , TI improved the 40 years old NE5534 and today's ne5534 at 0.5 bucks measures better than opa2134 (i've seen it with my own eyes) .It may not sound better because it doesn't have the even harmonic content of OPA2134, but who cares when most of the recordings until 2000 were made on ne5534?
For me, praising unobtanium complementary fet sounds like an easy way out. I appreciate you both for your achievement and professional career, but i wouldn't say that any op-amp is just useless for high end audio and only discrete stages can do it.Today's recordings are done exclusively on op-amps and digital equipment.
You probably sold lots of amplifiers to guys listening on a Nakamichi Dragon deck equiped with TL072 (D.self talks about that too, some of the best valve guitar preamps use it after 5 valves at the output) and i have no idea why would be all the world divided in such a way just because you sold some very expensive equiment to some very rich guys while most of the people couldn't afford an opinion.
D.Self praises too discrete design and actually shows some very performant bipolar stages with stunning performance in his books.Why would you just attack each other this way?Is it just because he made a technical evaluation on op amps after measuring them?
He was one of the best designers at Cambridge Audio and Soundcraft...You were rivals but Soundcraft still makes some of the best recording consoles in the world after D.Self designs...
By the way..once i wanted to throw away a Soundcraft eq and a guitar player who is my friend and is also a very good musician and well known in my country wanted it and after 11 years he still have it among very expensive RME recording equipment.I wonder why...
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It’s easy to diss Doug Self. He is a strongly opinionated objectivist and delights in skewering snake oil merchants. Bob Cordell is as much an objectivist, but a gentleman and a diplomat with it.
Say what you like, but both these authors cleared away mountains of BS with their books.
All power to the people!
Say what you like, but both these authors cleared away mountains of BS with their books.
All power to the people!
Doug is a good guy, and has written a bunch of good articles, my problem remains that his usual bibliography contains 8 of his own articles, a couple by Hawksford, and maybe one or two by Otala. Smiles please!
Hum.
Ruppert Neve must be turning in his grave.
You forgot to say that Bob Cordel is very open minded. (read my lips)
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