SS amp theory

[Brion55]

What book(s), websites and such would you suggest for learning SS audio power amp theory? I am well versed in general electronics and have worked with audio stuff for years, but never had a good reason or inclination to learn. Now I have plenty of time on my hands and would like to learn.

Thanks in advance.

 

[Stocker]

Others will be better prepared to answer such a question I'm sure, but I got a great deal of information reading Douglas Self's description of his Blameless class B amplifier, found without too much trouble on his website, via Google.

 

[andy_c]

The two biggies are:

Audio Power Amplifier Design Handbook by Douglas Self

High Power Audio Amplifier Construction Manual by Randy Slone

They are good complements of each other, as the first is oriented toward theory, the second toward practical considerations.

 

[jcx]

look for op amp circuit explainations as well, gain stages and compensation are very similar - national.com has classic design/app notes by widlar

you might want to download the free Lt SwitcherCad III Spice
http://www.linear.com/company/software.jsp

Spice simulation is a good learning tool to play with topologies and poke at the internals in ways not readily done with physical amps

 

[Greg Erskine]

The two biggies are:

Audio Power Amplifier Design Handbook by Douglas Self

High Power Audio Amplifier Construction Manual by Randy Slone

They are good complements of each other, as the first is oriented toward theory, the second toward practical considerations.

I recommend these two books as well.

I found Professor Leach's description of his amp from "go to woe" excellent.

http://users.ece.gatech.edu/~mleach/lowtim/

And I found Cambie's articles on the ETI480 helpful.

http://www.alphalink.com.au/~cambie/

 

[Fritzell]

I want to do the same thing as you actually. I have ordered the "Audio Power Amplifier Design Handbook" by Douglas Self (haven't recieved it yet tho), and im hoping to learn as much as possible so after i hopefully can build a complete amplifier and understanding every bit of it. That also help you do more efficient error searching if something goes wrong

 

[Leolabs]

Dont forget this guy too:John Curl

 

[vmike]

Another good source of transistor amp theory would be the 1960's printings of the GE Transistor Manual. The best of these would probably be the one published in 64, it has schematics and theory from which almost all of the since built solid state amps were derived. The 64 printing has a mostly black cover, the other good one is the 61 printing with a mostly white cover.

Old books can be your friends.

mike

 

[jpnascim]

What book(s), websites and such would you suggest for learning SS audio power amp theory? I am well versed in general electronics and have worked with audio stuff for years, but never had a good reason or inclination to learn. Now I have plenty of time on my hands and would like to learn.

Thanks in advance.

Hi Brion55,

I have "High Power Audio Amplifier Construction Manual" from Randy Slone and I confirm most of what has been said here by others. The book in general is a very nice reference. It is more towards practical issues of builing a nice amplifier (as andy_c pointed), it shows what are good topologies, what are not, gives a lot of simulation graphs, how stages interact with each other and etc. It also has ready designs for you to use and PCB board lay-outs too. It is all you need to build an amplifier and get it working. His writing style is also nice.

But attention, in my opinion, if you are a beginner in electronics you may not extract most of it (although it is ok to read). It is full of affirmatives that may sound mystical to the beginner (e.g. it won't explain how does a diff pair work in details), if you start looking for proofs in text you may not be satisifed. Sometimes I also found that Slone did not choose the best way to explain a circuit - he seems to think in a different way. You may need to complement with an Electronics Text book (e.g. Art of Electronics).

But I must say that this book is very, very good. It is rich, dense. And best of all, it gives you a chance to build an amplifier that works and sounds really good. (I built one myself)

Best regards,

João Pedro

 

[name773]

for a quickish intro, check out Rod Elliot's amplifier basics and amplifier design articles. all of his articles can be found here, and in particular the current sources/sinks/mirrors article is helpful when reading the other two.

 

[kkchunghk]

Hi,
I have the "High Power Audio Amplifier Construction Manual" also. I find the presentation of ideas logical and sensible. I 'm impressed enough to buy the opti-mos kit, which is described as the author's favourite.
This may seem a little off topic, but I think it relates to the credibility of the book (at least sections of it). It is the section that deals with the "myths" of valve amp. We can tell which side Mr. Slone is on about the valve vs. SS issue. The book claims that the valve sound people like so much is the result of second degree harmonic distortion present in the audio signal, and one can create this sound by conditioning the incoming signal, in other words adding the distortion deliberately, much like tone control.
I thought this is easy to prove. So, has anyone tried? What is the circuit like? I would like to have a go to put the circuit before the input of opti-mos to see what happens.
Appologies to all to be off topic.

Cheers,
KK

 

[sam9]

The book claims that the valve sound people like so much is the result of second degree harmonic distortion present in the audio signal,

Actually, quite a few tube amplifier fans agree.

Another probable element of "tube sound" is that when clipping, tubes are less unpleasent than SS amps. There is a good chance this is true, however it is easier to attain very high power levels (200+W) with solid state which is a means to make the point moot simply by not clipping. Brute force may be inellegant but it is often effective.

I have read (meaning this may be total baloney) that the (in)famous Carver demonstation wherein a SS amp was made to sound just like a tube amp to a room full of the golden eared was accomplished by the simple means of inserting a series resistor at the output. It raised the output impedance and hence the amp's transfer function. This altered the SS amp's interaction with the speakers (a reactive loads) to be similar to that of a tube amp.

Anyway some people really (I mean r*e*a*l*l*y !!!) enjoy the sound of tube amplifiers as comparred to SS. We just have to accept that. I see no real point to arguing about it.

 

[AndrewT]

Hi,
I recommend "the art of linear electronics" by the late John Linsley Hood published by Newnes.

 

[tschrama]

Sorry, but the number of errors and unsupported claims in "High Power Audio Amplifier Construction Manual" from Randy Slone disqualify it as a usefull book. You deffinety do not wanna learn about SS amps from that book. That guyy is just full of him self, but has really a mediocre brain.

much better:
- Douglas Selfs books
- JLH books
- Art of Electronics
- Rod elliots site is a very nice way to learn about SS amps.. print his site on paper and is can be a very good book

 

[Greg Erskine]

Sorry, but the number of errors and unsupported claims in "High Power Audio Amplifier Construction Manual" from Randy Slone disqualify it as a usefull book. You deffinety do not wanna learn about SS amps from that book. That guyy is just full of him self, but has really a mediocre brain.

tschrama,

You can't say "number of errors and unsupported claims" without pointing out the errors, you have to support your claim. It's your duty to help us that have Randy's book.

 

[tschrama]

You're right offcourse... and I knew I would get a reaction like this..

I bought Slone's book about 4 years ago via Amazon and I was impressed at first, but after reading Self's book and spending a lot of time on this forum, you cann't help but becomming sceptical. I haven't touched the book for more then a year know, so I'm really sorry that I cann't come up with the list you're asking. I tend to only remember my conclusions, and disgard the way I got them, leaving more room in my brain.

But just a hint, how many real measurements are in that book?

 

[Greg Erskine]

You're right offcourse... and I knew I would get a reaction like this...

I'm only joking, I'm capable of working fact from fiction. I just wouldn't dismiss his book because I disagree with some of his views. It's a good stepping stone in the learning process.

I've read most of the books and sites you recommend and they are all quite unique having their own opinions, style and level of technical information etc. All are excellent.

 

[sam9]

You can't say "number of errors and unsupported claims" without pointing out the errors, you have to support your claim.

Build an amp with mirror image input and VAS that uses current mirrors in the LTP's. There are three or four examples in the book. Come back and tell us your experiences. By "build" I mean physically construct, not just a SPCE model.

There is a lengthy thread on this.

 

[sam9]

But just a hint, how many real measurements are in that book?

I think Slone just fell into the "SPICE trap". Of course *no one* here on this forum ever does that. His subsequent books suggest he became aware of his error to some degree. After all, by all accounts the Opti-Mos is quite good and there are no current mirrors in the LTP.

I just wouldn't dismiss his book because I disagree with some of his views.

It wasn't his views (such as concerning tubes) that bug people it is circuits that function differently in real life. For instance he shows a triac based soft start circuit. Anybody ever build that? Notice anything annoying about it?

----------------
BTW, one needs to be cautious about some of the other books cited, though for different reasons. For instance some of Self's conclusions are valid for the "Blameless" or similar topology but are different for other topologies. (Try using his optimim bias voltages in a mirror image LTP-VAS.) Some readers over-generalize his conclusions without realizing this. I suspect Self himself would not do this and simply expects readers are bright enough use his methods to make their own measurements when circumstances change.

 

[tschrama]

BTW....a nice spice simulator is a great tool to learn about SS amps....