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Tube gear, on the other hand, does at least allow for easy part swapping. Unfortunately, too many stop at part swapping and never move up to comprehension. Mr. Rozenblit's book helps to pull the tube audio part exchanger into a comprehension of the how's and why's of the circuit itself.
Only by understanding what goes on in the amplifier can the part exchanger realize that there are no absolute best parts and poor parts. I am sure that Mr. Rozenblit is weary from being asked what is the best tube, best capacitor, best resistor, best wire, and my favorite, what is the best cathode resistor value PERIOD. "Best for what? What circuit? What tube. What load?" are my usual counter-questions, but the conversation seldom proceeds to the next logical step.
Audio Science
In the first half of the book in the section titled "Audio Science," he offers explanations for such topics as Conductivity and Resistivity, Capacitance, Skin Effect, Filters, Balanced Lines, Vacuum Tubes, and Dynamic Range. No formulas, just prose. The formulas appeared in his first book. All are fairly straight forward and easy to read. Although at times his explanations begin to ramble a tad, this actually serves to make them a much better read for the novice than the stilted textbook written primarily to impress the writers of other textbooks. Mr. Rozenblit is not out to impress anyone (which immediately disqualifies him from ranks of tube guru). Besides, he has not written a textbook; he wishes to inform. Furthermore, what he covers as it regards high quality audio cannot easily be found in any textbook, as topic of high quality audio seldom makes an appearance in any EE textbook. Thus, my unalloyed recommendation of his book for all tube audio beginners. Does this mean that the book is of value only to beginners? No, not at all; it is just that the beginner will profit from reading this book from cover to cover, while the
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more experienced tube circuit designer will probably find the last half of the book more engaging.
Projects
The second part of the book is devoted to tube audio projects. The cover claims six projects, but I only counted five: Transcendent OTL, Grounded Grid Preamp, Super Compact 150 Watt Amplifier, Single-Ended with Slam, and Grounded Grid Cascode Phono Preamp. The missing project is found in the Transcendent OTL design, which includes two versions: a 25 watt and a 80 watt OTL amplifier.
Here is where the meat is placed upon the table. These projects are the plans to what he sells for a living: the Transcendent Sound product line. Talk about open source! Many tube gurus will not reveal their dark secrets. But Mr. Rozenblit is not shy. Schematics and part lists fill the last half of the book.
(I have clasped a few secret circuits from many a tube master's hand and did not know whether I should laugh or cry. "Let me see if I got this right? "You have taken the circuit for a Dynaco PAS 3 preamp and you use different valued resistors in some places but not in others and you use some very expensive coupling capacitors. You are indeed worthy of veneration. May I touch the hem of your garment?" Working knowledge [well, sort of working knowledge] of one or two circuits and contempt and distain for fellow audiophiles are the only requirements to be a tube guru.)
Mr. Rozenblit joins the club of frank, commercial audio designers that already includes David Hafler, Erno Borbly, Nelson Pass, John Atwood and David Manley. He even raises the bar in that he actually does expect you to build his projects. He offers what is just as important as the schematic and a part list: practical advice on how to build an OTL amplifier or a line stage preamp. From the chassis to the wiring, he gives good advice that
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