Paul wrote:

It's almost mediocre

This is just another example of why McGraw-Hill made a big mistake in
picking up TAB-G/L and its fifty year history of bad technical titles
by people like Homer Davidson, Tom Kneitel K2AES and other so-called
tech writers. Poor pay rates, lack of any editing whatsoever and a
willingness by librarians and well-meaning soccer moms of nerds to buy
anything on the subject kept TAB slaughtering trees for naught for
most of half a century.

There is some useful information in this book, but not very much. You
would do better to study schematics of seminal Hafler, Carver (Phase
Linear), and Threshold designs along with articles in JAES and Audio
Amateur/AudioXPress magazines. Duncan, Self, and others have written
substantially better books on the subject.

As for all this "controversy" on tubes, the definitive source is
indeed still Hamm's JAES paper, "Tubes vs. Transistors". That Slone
doesn't cite it reveals that he just was too lazy to do his homework
because it actually reinforced certain of his arguments, or too dense
to perceive it. This paper has been reprinted so frequently that
anyone interested will be able to find it easily.

What do they mean by *high power* ?

My beefiest design to date was 1kW /ch. Plenty of companies offer more.
You can't even contemplate using tubes at that power level !

Graham