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An OK book but riddled with problems, both minor and serious.
1. Major issue of omission: The title should include the word "hi-fi" or "audiophile", because guitar and instrument amps (bass, keyboard, PA) are NOT mentioned at all.
2. Major issue of omission: OTL amplifiers are mentioned in passing, on one page only, a serous oversight. Obviously the author has no experience in that field.
3. Major issue of omission: Audio (input, MC, interstage and output) transformers are superficially covered, power transformers and chokes are covered in even less depth. You will not learn how to design, build or even evaluate or measure audio transformers from this book!
4. Major issue of omission: Some very important topics such as grid chokes and anode chokes (impedance coupling), transformer coupling, ultralinear connection and many others are only mentioned or covered very superficially.
5. Major issue of methodology: The book is methodologically and pedagogically unsound. For instance, amplifier circuits are discussed before the tubes were covered. The physics, internal structure and operation of triodes, tetrodes and pentodes is covered only on page 255 onward (too late).
6. Major issue of methodology: The book starts with BJTs (bipolar junction transistors) and op amps (solid state stuff) but makes no transition into valves, so any similarity between them and any differences (all are 4-pole networks, current or voltage amplifiers) are lost. Strangely FETs are not even mentioned, and they are similar in their operation to valves, so educationally this is a serious error.
7. Important issue: The circuit diagrams drawings are simple (sketches would be a more appropriate term) and miss lots of things, many have errors. For instance, SRPP drawing on page 122 (3rd edition) does not even have its output marked!
8. Important issue: On many occasions a concept or idea is mentioned but not illustrated or elaborated upon in any way, leaving the reader perplexed, asking "And what is that and why it is important?" These are called "hangers" because the authors leave them just hanging in the air. Also, for instance, on p332 speed-up capacitor is mentioned but it is not included in any of the drawings, except 11 page later, on page 343, but even then it is not marked or identified as such, and not even mentioned in the text below the circuit where it appears!
9. Important issue of "A picture is worth a thousand words". For instance, the author talks for 30 or more pages about phono equalization, but there is no drawing of a RIAA equalization curve anywhere in the book! This is unforgivable! Too much talk, not enough self-explanatory diagrams and drawings.
10. Only 3 power amplifier projects and a couple of preamp projects are given, which for a book of 618 pages (again, 3rd edition) is not enough, the book is more conceptual than practical. Most practical issues were meant to be covered in M. Jones' second book "Building Valve Ampifier", the sequel to this book, but that book is a total miss and even less practical than this one!
Perhaps "Valve Amplifiers" deserves 3 stars, but because of the strange writing style, poor drawings and very illogical sequence of topics, all of which make it a VERY DIFFICULT book to read and understand, especially for a beginner (which I'm not), I deducted one penalty point. before you buy it, study the sample pages using "Search inside" feature and you will 1. understand what I'm talking about here and 2. see if the book is for you or not.