Bob Cordell's Power amplifier book

PHEONIX · 2011-04-16 6:33 am

Bob Cordell said:
I agree with you that getting THD-20 (NOT just THD-1) down below 0.001% is difficult in a real-world circuit. However, getting simulated THD-20 further down will not necessarily be sufficient to get there, since the distortion floor might be set by implementation imperfections that have nothing to do with the simulation.

Cheers,
Bob

Hello Bob

I totally agree with you.

Regards
Arthur

Macleod · 2011-04-18 11:56 am

Thank you Bob for your explanation on the feedback network tuning.

I will try to retune your amp given your advices and deletting existing values as an exercice.

amptech · 2011-04-18 3:06 pm

This is a second good book for mosfet/bipolar amps by Randy G Slone...

I've used some of the circuits from this book and there out standing, there's plenty of projects to build even speaker protection systems...

Bob Cordell · 2011-04-20 1:52 pm

amptech said:
This is a second good book for mosfet/bipolar amps by Randy G Slone...

I've used some of the circuits from this book and there out standing, there's plenty of projects to build even speaker protection systems...

Hi amptech,

Which of Randy Slone's books are you referring to?

There was supposed to be a second edition of Randy's High Power Amplifier Construction manual published in March, but there seems to be conflicting information about its existence. I've tried to order it twice, and the orders subsequently were not able to be filled. The prices were over $100 as well, suggesting that if they existed they were extremely difficult to obtain. I would certainly like to get one if it is out there.

Cheers,
Bob

amptech · 2011-04-20 4:42 pm

Hello Bob, I got both of mine from Amazon uk, one was full of high powered amplification design works with foil lay outs plus in-depth circuity information. the 2nd one was pre-amp circuits with test power supply's for high end amplifier usage..

It's the black covered book of Randy's high powered amps.. this one gives full in depth coverage..

I brought mine second hand a from amazon they do good deal's..

Bob Cordell · 2011-04-20 10:50 pm

amptech said:
Hello Bob, I got both of mine from Amazon uk, one was full of high powered amplification design works with foil lay outs plus in-depth circuity information. the 2nd one was pre-amp circuits with test power supply's for high end amplifier usage..

It's the black covered book of Randy's high powered amps.. this one gives full in depth coverage..

I brought mine second hand a from amazon they do good deal's..

Hi amptech,

It sounds like you may have the first edition, but the second edition also shows a cover with quite a bit of black in it. Can you check and see which edition of the amp book you have?

Thanks
Bob

davada · 2011-04-21 1:30 am

Bob Cordell said:
Hi amptech,

It sounds like you may have the first edition, but the second edition also shows a cover with quite a bit of black in it. Can you check and see which edition of the amp book you have?

Thanks
Bob

Hi Bob,

Have a look here.

Amazon.com: High-Power Audio Amplifier Construction Manual (9780071599252): G. Randy Slone: Books

Oh never mind, it's out of print.

David.

BrianL · 2011-04-21 4:21 am

Bob,
according to another thread, Randy died a few months ago. It's possible the newer book was not completed.

Bob Cordell · 2011-04-21 11:48 am

davada said:
Hi Bob,

Have a look here.

Amazon.com: High-Power Audio Amplifier Construction Manual (9780071599252): G. Randy Slone: Books

Oh never mind, it's out of print.

David.

Hi David,

Thanks. I've seen this page before. The curious thing is that it supposedly came out in March, 2011, and yet here it is April and it is already said to be out of print. And there are places on the 'net that supposedly have it if you google on its ISBN (but so far no luck in actually getting a copy from these places). Strange...

Cheers,
Bob

Bob Cordell · 2011-04-21 11:51 am

BrianL said:
Bob,
according to another thread, Randy died a few months ago. It's possible the newer book was not completed.

Hi Brian,

Yes, Randy's death was a real loss to the audio community. I knew that he was having trouble completing the second edition, so I was indeed surprized to see the second edition appear on Amazon and other places, initially announced as being available on a pre-order basis.

Cheers,
Bob

amptech · 2011-04-21 2:44 pm

Hi Bob, your right there it's the first book and there's one were with pre-amp and filter ideas.

It's a shame he died he's books helped you get right in to design work from the ground up...

still there's plenty more useful information on the net....

davada · 2011-04-21 4:04 pm

If Randy's death was resent, there may be some estate issues preventing the books publication. I did the work of executor for my dad's estate and even for a simple estate it gets complicated.

David.

Bob Cordell · 2011-04-21 9:07 pm

davada said:
If Randy's death was resent, there may be some estate issues preventing the books publication. I did the work of executor for my dad's estate and even for a simple estate it gets complicated.

David.

Good point. I think he died last summer.

Bob

padamiecki · 2011-04-22 9:17 am

Hello,
could you advice how is possible to implement TMC to Yamaha AX400?
My guess is that it should be instead C130 using 5pF+680ohm+15pF
am I correct?
Maybe is another way to use TMC in this design?
However I wonder if is possible because tone regolators are coherent part of the amp...

AndrewT · 2011-04-22 10:13 am

I Like the Yamaha output stage, all the way from cascoded VAS to complementary output triple.

Shame about the 3 BJT input stage.

padamiecki · 2011-04-22 10:18 am

AndrewT said:
I Like the Yamaha output stage, all the way from cascoded VAS to complementary output triple.

Shame about the 3 BJT input stage.

That is why I deciced to buy it as "failured"
I was thinking to remove tone regulator and use fet/bjt cfp input instead those 3 bjts

and use TMC.
Next step will be use MKP caps instead the electrolytics.

Bob Cordell · 2011-04-22 6:50 pm

padamiecki said:
Hello,
could you advice how is possible to implement TMC to Yamaha AX400?
My guess is that it should be instead C130 using 5pF+680ohm+15pF
am I correct?
Maybe is another way to use TMC in this design?
However I wonder if is possible because tone regolators are coherent part of the amp...

Hi Pawel,

As near as I can tell, this amplifier does not use Miller compensation. In any case, it is extremely difficult and risky to recommend changes to compensation of a power amplifier at a distance. In any case, I can't suggest that you try TMC on this amplifier.

Cheers,
Bob

effebi · 2011-04-22 9:48 pm

On almost the same argument, is there any solid argument against implementing TMC on a bootstrapped VAS that drives a CFP output? I am speaking about a new project.
Thanks in advance
effebi

Bob Cordell · 2011-04-22 10:57 pm

effebi said:
On almost the same argument, is there any solid argument against implementing TMC on a bootstrapped VAS that drives a CFP output? I am speaking about a new project.
Thanks in advance
effebi

Hi effebi,

No, I see no argument against using TMC for such an amplifier.

Cheers,
Bob

1965GTO · 2011-04-22 11:02 pm

Hi regarding Randy S. This is the information I got from the publisher directly. I too was waiting with baited breath for his new book. Looks like Bob you are the man now!!!!

Thanks for getting in touch. Unfortunately, we will not be coming out with another edition of the book, as the author died before he was able to complete it.

I’m not sure what your needs are, but perhaps I can suggest another related title that was just recently published:

Designing Audio Power Amplifiers, by Bob Cordell, ISBN 007164024X

I do hope this will fulfill your requirements. Should you have any other questions, please don’t hesitate to contact me.

Best regards,

Bob Cordell's Power amplifier book

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