New Book Review

[gingertube]

Elektor have released a new book on Tube Amplifier Design.

"Fundamental Amplifier Techniques with Electron Tubes" by Rudolf Moers.

Fundamental Amplifier Techniques with Electron Tubes - ELEKTOR.com | Electronics: Microcontrollers Embedded Audio Digital Analogue Test Measurement

My copy arrived about a week ago and I have been browsing since.

This book very thoroughly covers the basics of tube operation and amplifier design in quite technical depth. It is at the level of a Technical College Text Book with in depth maths analysis and so will not suit everyone in the DIY community.

It is however an excellent technical reference.

Confused about (for example):
- Positive and Negative Grid Current
- Cathodyne Phase Splitter
- SRPP
- Cascode

This book gives you all of the basic formulae for gain, zout, zin etc with their full derivations from 1st principals. None of that "so it is therefore obvious that ...." when it never is, in the maths.

For example did you know that the gain of an SRPP stage with equal triodes and equal cathode resistors is always mu/2 and Zout is always rp/2 - I did'nt until I read this book.

Recommended for those of you with a bit of a maths/technical "bent", probably will go over the heads of those hobbiests who are mainly into cloning existing designs.

I find it VERY valuable and it sits on my bookshelf alongside my copies of RDH and Valley and Wallman.

Cheers,
Ian

[ruffrecords]

Originally Posted by gingertube

For example did you know that the gain of an SRPP stage with equal triodes and equal cathode resistors is always mu/2 and Zout is always rp/2 - I did'nt until I read this book.

It is only true if the bottom cathode resistor is un-bypassed. If the bottom cathode resistor is bypassed the gain is somewhat higher.

Cheers

Ian

[ruffrecords]

It is a very expensive book. I am trying to get my local library to obtain a copy so I can check it out thoroughly before spending so much money.

Cheers

Ian

[DF96]

And Zout is typically less than rp/2 - more like rp/3.

The stage with gain exactly mu/2 and Zout exactly rp/2 is the active load on a grounded cathode, with both cathode resistors bypassed. This may superficially look like an SRPP, but the output is taken from the bottom anode rather than the top cathode. I hope this is the reader's confusion, not a mistake in the book.

[the_manta]

Originally Posted by gingertube

For example did you know that the gain of an SRPP stage with equal triodes and equal cathode resistors is always mu/2 and Zout is always rp/2 - I did'nt until I read this book.

Is there a perfect derivation to that result in the book ?
There a few formulas for Zout of the SRPP stage (one by Amos and Birkinshaw, one from John Broskie etc...)
I don't need another book which is basically a composition of other, long ago pubished books. I see that everyday at the uni-library in classical/quatum mechanics. Nothing is more annoying than people who think they MUST write a book cause they spent some time with a topic.

The content index looks indeed interesting (though I don't need the chapter about construction) but the price is exorbitant.

[Michael Koster]

Originally Posted by the_manta

... Nothing is more annoying than people who think they MUST write a book cause they spent some time with a topic.

"For years, author Rudolf Moers searched for a textbook about electron tube amplifiers in order to learn how to design amplifiers using electron tubes, given that one has a reasonable knowledge of analog electronics. Since he never found such a book, he has written one himself..."

Oh great...

"To achieve this, he studied many radio books and did many measurements. This was followed by the organization of all the information, making many drawings and calculations and a lot of writing. By all this effort, a lot of knowledge about electron tube electronics, which was under the threat of being lost, will be retained."

Yeah right. A historical debt of gratitude is owed...

Pardon the sarcasm, but seriously, the real honest to ghod textbooks and references for vacuum tubes and tube amplifiers are still available; Valley and Wallman, Reich, RDH...

My big concern about this trend is that after all this information gets redigested, regurgitated, and sometimes reinvented for DIYers, future generations will be left with an oversimplified, Stereophile magazine version of vacuum tube knowledge.

Hmmm, maybe I could write a book about tube amps...

[SY]

Ouch, that price hurts! After my experience with Menno Vanderveen's latest book (see Linear Audio Vol 1 for a review), also from Elektor, I would wonder if they bothered getting the text translated and edited by someone with native-proficiency in English and an ability to write. That's one major advantage of the Morgan Jones books- the writing is crystal clear and (unlike Germans) he knows where his verbs to put.

[DF96]

The Contents list would suggest to me that the final text was not prepared by a native English speaker who was familiar with valves. It is generally OK, although too detailed, but in places expresses things in a way we probably would not (e.g. steepness instead of slope). It may still be perfectly understandable, but if a cheap paperback version comes out we may end up with a new generation of valve people who have to learn British, American and Elektor names for things.

[Bas Horneman]

the writing is crystal clear and (unlike Germans)

What have Germans got to do with this book? I know they started the war but you can't blame them for everything.

[SY]

"Whatever you do, don't mention the war!"

I had assumed from his name that the author was German- if he's Austrian or from some other Umlaut country, my apologies.