Audio Power Amplifier Design book- Douglas Self wants your opinions - Page 23 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th March 2013, 04:04 PM   #221
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
PMI an Hahfran,
What you are both saying is common in many industries. What you learn in school generally teaches toward the end goal, the way we have to use the information. I would have thought that at least on a basic level the physics of how a transistor or diode or other electrical device works would have been shown. But do you think that every EE should also have to have a degree in physics? I worked with polymer chemistry for many years and though I may have a very broad understanding of different polymer chemistry's does that mean that I should have been a chemist to use the polymers that I used. I was not formulating those, but I was doing material applications development. I needed to know how to use the chemistry, how I could apply that knowledge but not how the polymer chains were created. I doubt that many here besides Scott Wercer and a few others will ever have any need to fully understand how the photons are used to etch an integrated circuit, you may be interested on some level but that isn't necessary to apply the finished devices into a working circuit. The same would go for most designing an audio circuit, do you really need to understand the physics to work in this field? The mathematics alone to work on the parasitic level of an electrical circuit is already a fairly extensive knowledge base that you would need to understand to optimize many of these designs.
  Reply With Quote
Old 16th March 2013, 04:23 PM   #222
FoMoCo is offline FoMoCo  United States
diyAudio Member
 
Join Date: Dec 2012
Quote:
Originally Posted by Bob Cordell View Post
I hope I'm not misunderstanding you, but let me point out that most colleges do indeed teach the operation of the BJT as being a voltage-controlled device with its primary amplifying characteristic as being transconductance.
With all due respect, I must disagree. Most colleges I have seen tend to just gloss over that in lecture and maybe a paragraph in a textbook. They jump straight to the HFE explanation. It's simpler (even if not correct) and now that students are seen as "seats" and not students, it's getting worse.

Quote:
Originally Posted by forr View Post
Many people are convinced that BJTs are amplifying devices because the property of beta is very easily demonstrated. It may be the first experience shown with elementary amplifying devices. Then, the students take the wrong conclusion and retain it as an undoubtful fact.
That's exactly how I've seen it taught. Once the wrong way is learned, it's hard to unlearn. Especially because it works most of the time.

Quote:
Originally Posted by PMI View Post
Not all wrong, by a longshot, but from my own experience as a EE, I found out much later that most EE classes teach very little about how a device actually works. What they do teach, and very well, is the application and circuit design theory using the various types of devices. At the same time, there is simply little opportunity to delve into the physics.
That's exactly how my EE classes were. The application is actually a very good thing to teach, but when the rest is glossed over it's not really much of an education.
__________________
Account Deletion Requested: 1/26/2014
  Reply With Quote
Old 16th March 2013, 04:48 PM   #223
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
FoMoCo,
Sounds like you want a class or many classes in solid state physics of semiconductors. Do you really need this much knowledge to work in this field? You can always take additional classes, I have never seen any college or school that would deny you this opportunity. But there comes some point where a school has to set a curriculum that encompasses what they decide is a minimum requirement to graduate with a degree in a subject. Should an EE also have to take music appreciation classes before he is allowed to design audio equipment. Where do you draw the line, what is necessary to do the job. Now if you are given incomplete information leading you to incorrect conclusions and a lifelong misunderstanding of the workings of a device that could be a problem.
  Reply With Quote
Old 16th March 2013, 06:51 PM   #224
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
I have yet to meet an engineer who wasn't familiar with Ebers-Moll.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 16th March 2013, 07:02 PM   #225
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Sy,
Are those Ebers-Moll's the same ones who dig in my backyard, I thought they were just ground squirrels.........
  Reply With Quote
Old 16th March 2013, 08:26 PM   #226
FoMoCo is offline FoMoCo  United States
diyAudio Member
 
Join Date: Dec 2012
Quote:
Originally Posted by Kindhornman View Post
FoMoCo,
Sounds like you want a class or many classes in solid state physics of semiconductors. Do you really need this much knowledge to work in this field? You can always take additional classes, I have never seen any college or school that would deny you this opportunity.
I just don't think that I should take extra classes for what was common knowledge 20 years ago.

Quote:
Originally Posted by SY View Post
I have yet to meet an engineer who wasn't familiar with Ebers-Moll.
Ah... Now see... That is what is now just glossed over. I had to look it up. It was briefly mentioned as the Shockley equation and never mentioned again.
__________________
Account Deletion Requested: 1/26/2014
  Reply With Quote
Old 16th March 2013, 10:45 PM   #227
ontoaba is offline ontoaba  Indonesia
diyAudio Member
 
ontoaba's Avatar
 
Join Date: Nov 2009
Location: Kudus, Malang, Dieng
Quote:
Originally Posted by hahfran View Post
Oh I happened to be at IBM R&D where I designed ( at that time) ultra fast
micro CPU with ECL ....
if you don't understand the physics of semiconductors you won't ever get how BJTs function.
Hi, off course. Schools are (sorry) for degrees for looking for jobs to get money. They are not being researching that hard.
there in schools are no bjt except models and its function explanation, even there are disagrees about what bjt functions are. For fast system implement indeed the substrate are fragile from anything like stored energy, even interfere when some metal (ground or radiating plate) getting close. That's why chip amps are very limited.
In audio there are more complex function of bjt. Some bjt are sound better than other and linearity figures could not help.
  Reply With Quote
Old 17th March 2013, 01:03 AM   #228
owdeo is offline owdeo  Australia
diyAudio Member
 
Join Date: Jun 2003
Location: Sydney
When I did my EE degree I was taught the basics of semiconductor physics and bjt operation using the standard models talked about so far. But most of it never sunk in - I learnt enough to pass the exams, but frankly at that stage of life I was more interested in girls and drinking beer and enjoying life

Later on after thinking about it more and reading some excellent textbooks that I wish were standard in my courses such as those by your good selves Mr Self and Mr Cordell, I came to understand transistor operation more deeply, but there's still plenty to learn.

My point is, what you are taught at uni is only a grounding in these areas and while it would be nice to have these things taught more clearly and correctly, most of the students are not really going to "get" it at the time and the expectation is that they will study more deeply later on if and when required. If a particular individual chooses to believe all that he or she was taught in those early stages throughout their life/career without questioning it or trying to understand things more deeply, that is their choice and there's nothing a university can do about it. Besides, these days universities seem to be very much run as corporations, and as each year government funding is battled for, the accountants who "manage" them like to reduce costs by sacking admin staff and expecting the lecturers to do their work as well as their normal teaching and research. So give the academics a break I say!
  Reply With Quote
Old 17th March 2013, 01:34 AM   #229
owdeo is offline owdeo  Australia
diyAudio Member
 
Join Date: Jun 2003
Location: Sydney
Mr Self, to get back to your question (and I only have the 4th ed. to go on here): I would very much like to see your insightful and superbly clear analysis applied to some of the alternative topologies to the generic Lin. I also would prefer a larger format/ page size that would allow clearer graphs etc. But it sounds as though you've already addressed both so thank you and I look forward to reading it.

Can I also just say that I agree with Carlos that a little more respect is due. Whether or not we all agree with your philosophy regarding the value of subjective evaluation or think the sound quality (for those of us who believe such a thing exists ) of your designs is pleasing to our ears is irrelevant - the fact is you have taught most if not all of us plenty about our favourite subject and we are lucky that you've been generous enough to share it by publishing such excellent texts (as they all are). Indeed I suggest you have given many of us a solid foundation of knowledge to build on so that even if we do decide to start tweaking or designing our own gear, we at least have some idea what we're doing!

I still find it mind-boggling that many of my favourite recordings must have been produced using mixing consoles you designed or at least of similar design, yet the last step in the chain seems so critical to my listening enjoyment and I have found other approaches (eg discrete preamp designs) more satisfying. It makes no sense rationally, but there you are. I admire your stance against all the BS in this industry. So thank you, and best wishes with the new edition.
  Reply With Quote
Old 17th March 2013, 05:28 AM   #230
diyAudio Member
 
Join Date: Jul 2010
Location: Cacak
The essential reading for EEs:

Brian Eno, The Revenge of the Intuitive, Wired, Jan. 1999.

It is available on the net.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
The design of active crossovers- Douglas Self wants your opinions DouglasSelf Analog Line Level 283 12th August 2014 11:01 AM
Comments on Audio Power Amplifier Design Handbook by Douglas Self Samuel Groner Solid State 68 16th March 2013 10:26 PM
Douglas Self's Active Crossovers book forr Analog Line Level 8 31st December 2010 05:20 PM
New Douglas Self Book blmn Solid State 7 22nd July 2009 06:00 PM
book-audio power amplifier by Douglas Self mikee12345 Solid State 8 16th November 2003 01:16 AM


New To Site? Need Help?

All times are GMT. The time now is 02:59 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2