Of course Nelson is correct. This makes a real problem for 'engineers'. They want to put a number on everything. Yet, it is well known that total harmonic distortion (THD) is a LOUSY indicator of audio quality. For those of you who don't know this, it is because TOTAL harmonic averaging mixes the nasty higher order products with the relatively benign 2nd and 3rd harmonic distortion. Yes, 3rd harmonic distortion is relatively benign. If it wasn't, we could never enjoy analog tapes or any music recorded BEFORE digital recording was imposed.
Most of what serious high end designers concern themselves with is beyond normal measurement. This hasn't kept me from investing a lot into test equipment. All else being equal, I prefer the lowest distortion possible, especially reduction of higher order distortion to VERY low levels. Once again, I can only do so much with test equipment, in fact, I have proven to myself that my designs can sound lousy, yet measure just fine, yet with 'refinement' of the components in the circuit, my associates and I can make an outstanding product with the same topology. Why? I don't know, but I do it on a consistent basis. Only our ears can tell the difference, under these conditions. This is the 'extra' factor that designers can add to audio design, above and beyond topology improvements. It is difficult to put this into a book, although it deserves serious consideration.
Most of what serious high end designers concern themselves with is beyond normal measurement. This hasn't kept me from investing a lot into test equipment. All else being equal, I prefer the lowest distortion possible, especially reduction of higher order distortion to VERY low levels. Once again, I can only do so much with test equipment, in fact, I have proven to myself that my designs can sound lousy, yet measure just fine, yet with 'refinement' of the components in the circuit, my associates and I can make an outstanding product with the same topology. Why? I don't know, but I do it on a consistent basis. Only our ears can tell the difference, under these conditions. This is the 'extra' factor that designers can add to audio design, above and beyond topology improvements. It is difficult to put this into a book, although it deserves serious consideration.
Measurement device like Audio Precision is so expensive. Does the one who can be called a designer must have this?
If I got one of these, maybe not realized, it will direct me to designs that is good to this AP----> good measurement designs, forgoting the good sounding ones. Why? Because I can see all the measurement results with numbers. SQ cannot be quantified. Man satisfied if he reaches a goal. Maybe getting a design that is good to measurement devices satisfies the designer too soon. And because that design is going through hard work,money and time consuming, the designer will argue for it.
Mr. Curl,
I get important lesson from you. All this time, all I heard is "Even harmonic is nice, odd is nasty". But you class them not by even or odd, but by high order and low order. It makes more sense for me by classified them high order and low order.
If I got one of these, maybe not realized, it will direct me to designs that is good to this AP----> good measurement designs, forgoting the good sounding ones. Why? Because I can see all the measurement results with numbers. SQ cannot be quantified. Man satisfied if he reaches a goal. Maybe getting a design that is good to measurement devices satisfies the designer too soon. And because that design is going through hard work,money and time consuming, the designer will argue for it.
Mr. Curl,
I get important lesson from you. All this time, all I heard is "Even harmonic is nice, odd is nasty". But you class them not by even or odd, but by high order and low order. It makes more sense for me by classified them high order and low order.
In my profession, understanding basic concepts and principles correctly and clearly is the key for many various applications of them successfully. Often juniors laugh at me. I think that the same applies for my DIY hobby life.
The followings help me very much:
- Albert Paul Malvino: Electronic Principles (MaGraw-Hill Book Co.)
- Horowitz & Hill: The Art of Electronics (Cambridge University Press)
- Articles of www.passdiy.com
- K A Stround: Engineering Mathematics (The Macmillan Press LTD)
Reading NP’s articles, I sense that he understands basic things correctly and clearly so that he has no problem to fearlessly use them to his own advanced applications. For the same reason, he knows how to write many parts in easy ways which are actually complicated. I really admit that I have learned many valuable things from his articles and comments (Sometimes he puts some traps here and there, though.).
The followings help me very much:
- Albert Paul Malvino: Electronic Principles (MaGraw-Hill Book Co.)
- Horowitz & Hill: The Art of Electronics (Cambridge University Press)
- Articles of www.passdiy.com
- K A Stround: Engineering Mathematics (The Macmillan Press LTD)
Reading NP’s articles, I sense that he understands basic things correctly and clearly so that he has no problem to fearlessly use them to his own advanced applications. For the same reason, he knows how to write many parts in easy ways which are actually complicated. I really admit that I have learned many valuable things from his articles and comments (Sometimes he puts some traps here and there, though.).
jh6you said:
Good man!
jh6you said:
Good introductory books, particularly Stroud, and Malvino.... 🙂
what is the different between
Engineering Mathematics
K. A. Stroud, Dexter J. Booth
and
Advanced Engineering Mathematics
K. A. Stroud, Dexter J. Booth
?
Engineering Mathematics
K. A. Stroud, Dexter J. Booth
and
Advanced Engineering Mathematics
K. A. Stroud, Dexter J. Booth
?
For me, 'engineering mathematics' would not be my first choice as a reference. Sure, math is important, BUT most electronic design uses minimum math, just algebra.
ElectronicsTech said:
Stroud RIP....4th edition was his last revision.....Booth produced 5th edition with Stroud's consent before the later passed away.....i prefer 4th edition...and 3rd edition of 'Further Engineering mathematics'
These are the best teaching books on the subject ever written...Period.
Sometimes, the feedback is a kind of geometric series action.
I try to see the end result how to converge.
AC (or wave) often expressed by complex numbers.
I try to see the physical meaning of the expressed complex numbers.
I try to see the end result how to converge.
AC (or wave) often expressed by complex numbers.
I try to see the physical meaning of the expressed complex numbers.
Here I stay alone. My family is enjoying life away from me. Yeah... I'm giving them good opportunity. Meanwhile, I also enjoy going out for drinking freely. But, I'm sick of going out for dinner every evening. I want to make my own food. I don't know how to cook. OK, I buy cook books and read and read and read...
I still don't know exactly how to make my dinner. Reading the books, however, I see one thing common. All books say the same. When we cook, we make one by one. We fry hard material first, then fry medium stuffs second, and stir them together to the last soft materials and finish the cook. I think this is the very basic principle in cooking. If I meet indicating this principle at the very first place, I can save my time and rather quickly I can enjoy cooking and try to make my own various food. I'd like to meet the book, whatever it is, helps me in this way.
I still don't know exactly how to make my dinner. Reading the books, however, I see one thing common. All books say the same. When we cook, we make one by one. We fry hard material first, then fry medium stuffs second, and stir them together to the last soft materials and finish the cook. I think this is the very basic principle in cooking. If I meet indicating this principle at the very first place, I can save my time and rather quickly I can enjoy cooking and try to make my own various food. I'd like to meet the book, whatever it is, helps me in this way.
jh6you, I think you are right. When designing audio amps, the most important thing is to remember what you are trying to design---A GOOD SOUNDING AMPLIFIER. There are guidelines such as 'low higher order odd harmonic distortion' 'fairly high slew rate' and 'the first watt is the most important'. If you follow these guidelines, you can not often go wrong, YET these guidelines are often ignored.
Detailed differences come with experience: For example, should we stabilize a feedback controlled power amp with an output coil? We used to use them, but you will find them missing with most hi end designs,today. Why?
Should we use a push-pull class AB design, or a single ended class A design? Often the class A design will sound better, BUT remember it MUST be class A, and the push-pull design COULD be class A as well, BUT you would lose much of its potential output power, or have to increase the heatsink considerably.
IF you make the push-pull power amp class A, with the same quiescent current as the single ended design, then other design details may dominate, such as stage complication, amount of negative feedback, etc, rather than single ended vs push-pull.
However, on the other side: Should we put balance pots in our push-pull amps to null out the last bit of 2'nd harmonic, or should we leave the residual 2'nd harmonic distortion if it isn't too high? Balance pots tend to complicate the design, is this a worthwhile tradeoff?
These are examples of the decisions that we designers have to make. We don't always agree, and that makes for different products in the audio marketplace.
Detailed differences come with experience: For example, should we stabilize a feedback controlled power amp with an output coil? We used to use them, but you will find them missing with most hi end designs,today. Why?
Should we use a push-pull class AB design, or a single ended class A design? Often the class A design will sound better, BUT remember it MUST be class A, and the push-pull design COULD be class A as well, BUT you would lose much of its potential output power, or have to increase the heatsink considerably.
IF you make the push-pull power amp class A, with the same quiescent current as the single ended design, then other design details may dominate, such as stage complication, amount of negative feedback, etc, rather than single ended vs push-pull.
However, on the other side: Should we put balance pots in our push-pull amps to null out the last bit of 2'nd harmonic, or should we leave the residual 2'nd harmonic distortion if it isn't too high? Balance pots tend to complicate the design, is this a worthwhile tradeoff?
These are examples of the decisions that we designers have to make. We don't always agree, and that makes for different products in the audio marketplace.
john curl said:
I could be wrong, but i suspect jh6you is presently an engineering student, for whom a solid background in quantitative analysis is essential to avoid being bent by subjective dogma and superstition... 😉
Oh, and jh6you, you may want to supplement Malvino later perhaps with the following:
http://www.amazon.com/exec/obidos/t...f=sr_1_1/103-9304677-2041464?v=glance&s=books
http://www.amazon.com/exec/obidos/t...f=sr_1_1/103-9304677-2041464?v=glance&s=books
http://www.amazon.com/exec/obidos/t...f=sr_1_1/103-9304677-2041464?v=glance&s=books
Good luck with your studies...... 🙂
Well, Mike......
It depends wether he wants to design stuff, or theorise how it works.
Experience trumps theory in the real world that most engineers work in. Your world is obviously much different. Which is fine by me..........really!
Your books would probably make interesting reading, but I suspect 99% of the guys here would learn more reading a "cookbook" by Don Lancaster or Walt Jung.
Or Bob Pease. Even if he thinks that audiophiles are nuts.
Jocko
It depends wether he wants to design stuff, or theorise how it works.
Experience trumps theory in the real world that most engineers work in. Your world is obviously much different. Which is fine by me..........really!
Your books would probably make interesting reading, but I suspect 99% of the guys here would learn more reading a "cookbook" by Don Lancaster or Walt Jung.
Or Bob Pease. Even if he thinks that audiophiles are nuts.
Jocko
Mikek, I asked a specific question about a specific series of books, specifically: 'Advanced Engineering Mathematics' Later, I realized that I could go to Amazon, myself and find out about this book. I have several books that are similar myself, specifically: 'Handbook of Applied Mathematics for Engineers and Scientists' Max Kurtz; 'Applied Analysis' Lanczos; and 'Numerical Methods of Scientists and Engineers' Hamming; etc, but I don't use them as much as several other reference books, At least we agree with Gray and Meyer.
As far as equating experience with superstition: That is what keeps you from moving forward in audio design.
As far as equating experience with superstition: That is what keeps you from moving forward in audio design.
Re: Well, Mike......
University Students in electronic engineering NEED a SOLID background in mathematics....Period.
It is on this basis that i recommended these specific textbooks....
Jocko Homo said:
University Students in electronic engineering NEED a SOLID background in mathematics....Period.
It is on this basis that i recommended these specific textbooks....
john curl said:
I tried reading that one. It's brutal! 🙂 The man was brilliant. Invented the FFT back in the '40s I think, though Cooley and Tukey (sp?) got credit for it much later.
john curl said:
It is not so much experience as what is demonstrably culled from that experience which counts.....
As for me 'moving foward' in audio design, it depends on what direction you think 'foward' lies.....
The following embodies my prefered meaning of the phrase 'moving forward in audio design':
http://www.meridian-audio.com/welcome.htm
http://www.z-sys.com/
A competent audio designer in the 21st centuary must have a thorough grasp of mathematics to have any hope of being usefully involved in the creation of DSP based systems.....
Anyone who suggests otherwise will rapidly become more defunct than the dodo.....
My interest in audio systems focuses mainly on DSP applications; linear power amp. design is a lot simpler and straight foward than a great many 'gurus' would have us believe.
http://www.dspguru.com/
Guys like you might "create" it.....
You will always need guys like me to get it to work.
Once DSP becomes commonplace, there will lots of cookbook solutions available to those who don't want to spend half their life learning the math and/or wrtiting pipeline code.
Jocko
You will always need guys like me to get it to work.
Once DSP becomes commonplace, there will lots of cookbook solutions available to those who don't want to spend half their life learning the math and/or wrtiting pipeline code.
Jocko
Brilliant thread!
I use the Boylestad and Nashevsky (Prentice Hall) book for my reference. Reasonably mathematical, but clear with many worked examples. Recommended.
Agree emphatically with John's comments about reducing high order distortion, AND getting just about any topology to sound good with proper voicing.
Cheers,
Hugh
I use the Boylestad and Nashevsky (Prentice Hall) book for my reference. Reasonably mathematical, but clear with many worked examples. Recommended.
Agree emphatically with John's comments about reducing high order distortion, AND getting just about any topology to sound good with proper voicing.
Cheers,
Hugh
- Status
- Not open for further replies.