Mikek you are incorrect. It only LOOKS SIMPLE! Thanks for the websites, this and other links is what I really appreciate from this website.
Bob Stewart of Meridian is a colleague. He and I first met in 1972 at a Londen AES session with Baxandall giving a talk. He invited me to a party at his house, and we listened to his system. First, we had discussed the problem of E-I output limiters and sound quality. While we were listening to music, Bob took some snips and cut out the protection. The sound improved significantly. Then, at the end of the night, I gave Bob the secret of the complementary differential input stage. After all, I had already used it for 4 years, and Southwest Technical had discussed it in print in 'The Audio Amateur'. Well, in 1973, Bob wrote a great article for WW, but at the end of the article, it was mentioned that a new audio circuit was under patent review, and that it was a significant improvement. Guess what the circuit was? I made a telephone call to Bob and accused him of trying to patent the circuit that I had given to him. He admitted to it, BUT said" The patent didn't get through, so we can still be friends. " Oh well! If you are at the AES, SF in Oct, maybe we can all go to dinner and discuss this and other things. ;-)
Bob Stewart of Meridian is a colleague. He and I first met in 1972 at a Londen AES session with Baxandall giving a talk. He invited me to a party at his house, and we listened to his system. First, we had discussed the problem of E-I output limiters and sound quality. While we were listening to music, Bob took some snips and cut out the protection. The sound improved significantly. Then, at the end of the night, I gave Bob the secret of the complementary differential input stage. After all, I had already used it for 4 years, and Southwest Technical had discussed it in print in 'The Audio Amateur'. Well, in 1973, Bob wrote a great article for WW, but at the end of the article, it was mentioned that a new audio circuit was under patent review, and that it was a significant improvement. Guess what the circuit was? I made a telephone call to Bob and accused him of trying to patent the circuit that I had given to him. He admitted to it, BUT said" The patent didn't get through, so we can still be friends. " Oh well! If you are at the AES, SF in Oct, maybe we can all go to dinner and discuss this and other things. ;-)
One book I can recommend if you really want to understand (1) opamps and (2) feedback amps is Jiri Dostal's Operational Amplifiers. As I said, it covers more (feedback) ground than just opamps. ISBN 0-7506-9317-7 from B-H.
If you want to read why is makes so much fun to find out how things work, get Feynman's 'The pleasure of finding things out'. from Pinguin Books
Edit: As an interesting read: Albert Einstein: 'The world as I see it', Citadel Press.
A very personal and political statement of a man not just a great physicist but a great MAN.
Jan Didden
If you want to read why is makes so much fun to find out how things work, get Feynman's 'The pleasure of finding things out'. from Pinguin Books
Edit: As an interesting read: Albert Einstein: 'The world as I see it', Citadel Press.
A very personal and political statement of a man not just a great physicist but a great MAN.
Jan Didden
I bought it, but I am not font of it. I've you wanna leanr how to design nice audio equipment, it is not very usefull. There too little information about noise, linearity, low voltage design.. everytime I wanna look something up, I cann't find in it.. I looked at 'The Art of Electronics', but is was way too expensive... now I regret I didn't buy it.. Self's book and John Linselyhood books are nice, and give me ideas to start with... my first electronics book that I really liked was ' A practicle introduction to electronic circuits, by Martin Hartley Jones... really nice .. made me feel that I could understand everthing if I studie at it.
The right book
Hi JH!
Yes!
I found a book for speakers
Audio Transducers, by Earl Geddes @$70 US
http://www.google.com/search?hl=en&...ucers"&as_q=geddes&btnG=Search within results
It's by an engineer who designs speakers and is written for engineers. It's heavily theoretical and the mathematics are nearly opaque for me. But nonetheless, its the book I need. It takes the voodoo out of speakers.
I should explain. Forty years ago my father wanted good speakers he could not afford to buy. The Heathkit amplifier solved the electronics quality and he'd found a decent turntable/tonearm so the (not very well educated) son was asked if he could help out..
Iwent to the university library for weeks and read things by Beranek, Olsen, Klipsh, etc and got down to designing the speaker.
I'd learned a lot about:
Sound.
Psychoacoustics.
How speakers work
What makes a speaker good.
Placement of speakers.
Compared to a real professional I didn't know very much at all because my mathematics wasn't (and isn't) up to the task but because I'd worked from first principles those speakers sounded very good then and they still sound OK.
These days I've come back to the interest in HiFi and an awful lot has happened in the interim. Electronics are better, source signals are better, speakers are better (but they are still the weak link in the reproduction chain), and a lot more research has been done..
And, of course, there is now the internet and its huge information.
But when is all said and done, I need a book about speakers. The one with first principles. The one I can refer to again and again. The one in which every paragraph and drawing counts. Despite my technical deficits, with effort, I get great insight.
The chapters on crossovers, waveguides, small room acoustics and distortion are worth the price of the book in terms of my future avoided unfocused effort, money and dis-satisfaction.
Hi JH!
Yes!
I found a book for speakers
Audio Transducers, by Earl Geddes @$70 US
http://www.google.com/search?hl=en&...ucers"&as_q=geddes&btnG=Search within results
It's by an engineer who designs speakers and is written for engineers. It's heavily theoretical and the mathematics are nearly opaque for me. But nonetheless, its the book I need. It takes the voodoo out of speakers.
I should explain. Forty years ago my father wanted good speakers he could not afford to buy. The Heathkit amplifier solved the electronics quality and he'd found a decent turntable/tonearm so the (not very well educated) son was asked if he could help out..
Iwent to the university library for weeks and read things by Beranek, Olsen, Klipsh, etc and got down to designing the speaker.
I'd learned a lot about:
Sound.
Psychoacoustics.
How speakers work
What makes a speaker good.
Placement of speakers.
Compared to a real professional I didn't know very much at all because my mathematics wasn't (and isn't) up to the task but because I'd worked from first principles those speakers sounded very good then and they still sound OK.
These days I've come back to the interest in HiFi and an awful lot has happened in the interim. Electronics are better, source signals are better, speakers are better (but they are still the weak link in the reproduction chain), and a lot more research has been done..
And, of course, there is now the internet and its huge information.
But when is all said and done, I need a book about speakers. The one with first principles. The one I can refer to again and again. The one in which every paragraph and drawing counts. Despite my technical deficits, with effort, I get great insight.
The chapters on crossovers, waveguides, small room acoustics and distortion are worth the price of the book in terms of my future avoided unfocused effort, money and dis-satisfaction.
john curl said:
It IS simple...John....if one applies a logical approach with attention to engineering detail.
john curl said:
I am not surprised.....SOA protection circuits of the 70s were appalingly designed....
john curl said:
Perhaps you know something i don't in this regard....
....but from my experiments this arrangement is rather disapointing.....
john curl said:
Drinks on you?
Bob Stuart is a sharp guy, but the really interesting folks were Michael Gerzon and Peter Craven. (I think I got their names right). They developed the lossless data compacting scheme. Maybe Peter will be coming over to this AES, haven't seen him in years. Trust me, he is just as crazy as I am. ;-)
Just curious: how can someone understand the concept of poles and zeros in the complex plane without understanding... the complex plane? And contour integrals?
mikeks, I'm as scientific and logic-oriented as anyone, but it just ain't as simple as you make it out to be. Audio amplifier design has both a science and art component. The art component is one that just can't be taught. Some people can pick it up with some experience, but not everyone can. For example, where issues like overload performance intersect with psychoacoustics, equations, simulations, and bench tests just cannot get you anywhere. You have to listen.
mikeks, I'm as scientific and logic-oriented as anyone, but it just ain't as simple as you make it out to be. Audio amplifier design has both a science and art component. The art component is one that just can't be taught. Some people can pick it up with some experience, but not everyone can. For example, where issues like overload performance intersect with psychoacoustics, equations, simulations, and bench tests just cannot get you anywhere. You have to listen.
SY,
I think I get your drift, but I look at it from a different angle. All the topics you mention under 'art' are really just like any other engineering issue, known and documented. I think what we you call art is the skillfull compromising between conflicting engineering requirements.
With experience, you built up a 'feeling' on the final result from different compromises because you have done it umpteen times so you know what to expect and therfor can cut corners in the formal analysis, but it is based in solid engineering.
Jan Didden
I think I get your drift, but I look at it from a different angle. All the topics you mention under 'art' are really just like any other engineering issue, known and documented. I think what we you call art is the skillfull compromising between conflicting engineering requirements.
With experience, you built up a 'feeling' on the final result from different compromises because you have done it umpteen times so you know what to expect and therfor can cut corners in the formal analysis, but it is based in solid engineering.
Jan Didden
mikeks, I agree with you. Actually, HIS two sons are university students. First one's major is "electronics." He, however, does not talk with his son about electronics. They normally have dialog, arguing "I need this money" and "why do you need that money?" kind of things.
Jocko, yes, I want theory how it woks, not for design stuff.
FrankWW, thanks. I'll buy that book as soon as my credit card works again. Using credit cards here is often troublesome.
John Curl, I got your points. Particularly, I respect the "experience." By the way, one funny mathmatics professor always made me sleep in the class room. At last, even once I saw his face, I "zzz..."ed. Today, I have to refer to the engineering mathmatics book.
These days, I know where are acting loads. I see roughly how they are distributed into inner parts of the complicated structure. And, I know roughly how they are balanced with complicated external supports. These are all I know, and enough for me to maintain my job. Meanwhile, young fellows use lot of advanced computer-based analysis tools and often bring up with strange results. Sure, my comments, saying "try to catch the basic principle", make most of them feel unhappy. Anyhow, I respect basic principle. Of course, experience too. I wish the same also apply in audio world.
Jocko, yes, I want theory how it woks, not for design stuff.
FrankWW, thanks. I'll buy that book as soon as my credit card works again. Using credit cards here is often troublesome.
John Curl, I got your points. Particularly, I respect the "experience." By the way, one funny mathmatics professor always made me sleep in the class room. At last, even once I saw his face, I "zzz..."ed. Today, I have to refer to the engineering mathmatics book.
These days, I know where are acting loads. I see roughly how they are distributed into inner parts of the complicated structure. And, I know roughly how they are balanced with complicated external supports. These are all I know, and enough for me to maintain my job. Meanwhile, young fellows use lot of advanced computer-based analysis tools and often bring up with strange results. Sure, my comments, saying "try to catch the basic principle", make most of them feel unhappy. Anyhow, I respect basic principle. Of course, experience too. I wish the same also apply in audio world.
I think the problem is not what is better, maths or experiences. Our maths models are still very poor to describe complexity of reality. Did you ever see completed maths model of performance of audio chain? We try to describe only small parts of it (and in only single way). Therefore still remains a big place for the ‘art’ and experiences.
AES member can be anyone working / active in audio engineering, even from day-1, with zero experience. An associate member is someone who is interested in audio even without working in it (like me ), and of course there are Student members (reduced costs).
The idea (as I see it) of the AES is to exchange ideas, discuss them, weed out the funny ones before someone falls on his face etc. So, membership of AES says nothing about your expertise or experience, but it says everything about your interests and having access to a very big sea of experience, documentation and network.
Now you can become an associate member on-line for I think 30 US $ and have access to all that. Although you still need to pay to download articles, designs, papers etc, they are half-price for members so you start making money after 6 downloads.
Jan Didden
), and of course there are Student members (reduced costs).The idea (as I see it) of the AES is to exchange ideas, discuss them, weed out the funny ones before someone falls on his face etc. So, membership of AES says nothing about your expertise or experience, but it says everything about your interests and having access to a very big sea of experience, documentation and network.
Now you can become an associate member on-line for I think 30 US $ and have access to all that. Although you still need to pay to download articles, designs, papers etc, they are half-price for members so you start making money after 6 downloads.
Jan Didden
The AES isn't what it used to be. It is almost impossible to get anything of value to design engineers into the AES Journal, these days. This was not always the case, and I recommend anyone to read AES journals 20 or more years old to answer MANY of the questions asked on this website. The latest journals will please some of my critics, but they rarely give me much engineering insight. This is because the AES Journal was taken over, about 25 years ago by Dr. Lipshitz et al, and he made sure that Walt Jung, Matti Otala, and probably anyone else like us, could not easily contribute. We can still give papers at conventions, but that's it. The argument was given that the AES is a 'Journal of Record' which precludes any controversial 'new' material.
This is why 'hi end' has broken away from the AES. There are still some contributors to the AES who have not been completely turned away, such as Dr Hawksford and Dr. Peter Craven. I always look forward to their articles in the AES Jounal, as I know I will get something from them.
PS, I personally have been an active member of the AES since 1966, and have contributed my time to promoting its affairs, just not lately.
This is why 'hi end' has broken away from the AES. There are still some contributors to the AES who have not been completely turned away, such as Dr Hawksford and Dr. Peter Craven. I always look forward to their articles in the AES Jounal, as I know I will get something from them.
PS, I personally have been an active member of the AES since 1966, and have contributed my time to promoting its affairs, just not lately.
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