Rating: 
Summary: More tirade than guidebook
Review: Generally, books on design give you an overview of the basic problem reduced to essentials, explore a few approaches, cover some necessary issues and walk one through some extant solutions. There is very little of that here, mostly, it's some disjointed ramblings on the bad ideas of "some audiophiles", and then he presents his circuit with little explanation, assuring us that it is "the best" and that others are inferior. There is then some commentary on chasing down surplus heatsinks and power transformers and building some fixturing.
Of this entire book, thirty or forty pages at the very most are useful and then only if you want to build his amplifier. I'm not even an audio engineer and just looking at his schematics I can see where the Bongiorno, Carver and Hafler designs we all studied in the 70s and 80s show those designers learned things he hasn't.
If you want a powerful audio power amp cheap my recommendation is that you find an old Phase Linear or Dyna or similar solid state amp with chassis, heatsinks and power transformer and fix it. They can be bought not working with good transformers for fifty dollars and you will spend more for surplus heatsinks alone. Building your own chassis will require a sheet metal brake and shears and possibly a vertical milling machine.
Even if you are set on building from scratch, circuitwise, a Phase Linear design is going to be a better choice than Slone's pet circuit. Others have said he cribbed the basic layout from Doug Self;I can't say, never having read any of these. As pitiful as the DIY market is in the United States, though, I have to believe that the best designs are the work of professionals as opposed to an author without industry portfolio, especially one writing for a publisher as famously lackadaisacal and cheap as TAB.
Rating:
Summary: It just isn't so
Review: I have built solid state and tube amplifiers as well as having worked on, listened to, and sold both kinds for both professional and home use. I think I know a little about amplifiers. Slone does too, but not as much as he thinks.
This book is just one disgruntled technofundamentalist's cranky ranting. He presents his projects after his ranting against other approaches as though they were the inerrant gift from the amplifier-deity, without any good walkthrough as to the whys and wherefores.
Unfortunately for him, some of us question all things. We question why professional mastering and mixdown engineers as well as serious listeners don't believe all amplifiers sound the same, good-measuring or otherwise. We question why THD and bandpass measurements are even considered relevant anymore when there is no correlation between them and perceived sound. And we especially call into question why his designs have not swept the DIY community and ben brought into commercial manufacture "through the back door", if they're so great, as happened with the seminal articles, first Russ Hamm's JAES paper and then Alan Douglas' article "Tubes in Japan", which was the first inkling that Japanese audiophiles and some sneaky snake audio dealers had nearly eviscerated America of the classic Western Electric theatre gear and horn speakers. Within a year Joe Roberts had introduced "Sound Practices" magazine, DIYers were cloning WE 91's, and mainstream High End makers were selling single ended amplifiers. If Slone's amp were anything but mediocre, it would have happened again. It is, it hasn't, and it won't. Phooey on you, Slone!
Rating: 
Summary: Not the best solid state book
Review: It's become a national obsession, for some reason, to read-or flip through-this book and either praise it to high heaven or declare it better printed on soft, absorbent paper so that it would have some utility in the world. I'm not going to do either one, because it's neither terribly good nor terribly evil.
If you want to cobble up some relatively inexpensive utility grade audio amplifiers at a somewhat lower cost than buying them-trading off your time, any warranty, resale, et al-which, it seems to me, is your right, this book provides schematics, PCB layouts, and enough commentary to get you going. Is that so rotten?
However, it doesn't connect the theory and practice very well. And it does contain a lot of opinion that is biased to some degree (isn't opinion always?) and marginally incorrect statements seemingly calculated to irritate the high end crowd. (Pro recording studios do use a lot of tube equipment, and not for coloration: almost all opera recordings are done on Neumann tube mics, for example.)
I would pick any of Doug Self's books or several others over this one if building these specific amps were not your primary goal. It's a hobby project book, period.
And, as a matter of interest, transistors-bipolar or FET-are not "more neutral" or "accurate" or linear than vacuum tubes. They are (relatively) low impedance devices and they come in N and P flavors, which means no output transformer is needed and therefore more, much more, negative feedback can be used to improve bandwidth and THD measurements. Alas, NFB is a tradeoff and more is not necessarily better-which is what the real pros started figuring out in 1972 (yes, the storied Russ Hamm!) and the 'subjective' backlash started. So, Slone is really being a little disingenuous,and he knows it...but then again, so are the high end tube vendors, because most of them are selling a sizzle that's out of proportion to the steak, and one that's often crudely built beneath the pretty machined front panel at that. Two wrongs don't make a right, but our entire system of commerce is built on the proposition that three lefts do.
Rating:
Summary: High end, these amps sure aren't!
Review: Most of the author's thrust in this book and in his other audio construction book is that sound quality in amplifiers is soley attributable to certain measurable parameters. The high end audio industry, as defined by small specialist product lines sold by specialist dealers and advertised and described in "Stereophile" and "The Absolute Sound" magazines, is in simple terms a scam.
Naturally, his designs provide better sound at much less cost.
Unfortunately, for hobbyists and serious music reproduction fans, he's wrong. Circuits and parts do have sonic faults and attributes test sets, as useful and ingenious as they are, just can't address. Gas spectroscopy is an incredibly useful tool for science, but it's of little use in separating truly great wines from Thunderbird. These amps and associated circuits are perhaps not audio Thunderbird, but they're not a fine Chardonnay.
Can the homebuilder build electronics to equal the best High End equipment? Given a first rate electrical engineering education, a machine shop, transformer winding fixtures, and a lot of time, effort and money-absolutely. The hobbyist of more modest skills and facilities can have fun and build stable, reliable and musically reasonably okay gear, but it's important to realize you usually have some substantial limitations. (On the other hand your time is not money and you can build around choice surplus or salvaged parts that commercial manufacturers of less than the most expensive gear can't design around.) Most people will find it hard to justify the necessary space, time, and money that need to be invested unless they are serious electronic hobbyists to begin with.
Where I find real fault with Slone is his attitude, as he obviously has a problem with the High End industry that goes past the technical. If he likes cheap table wines better than expensive ones, that's his right, but he's simply wrong to insist they are the same thing or better. If you have the skills and test equipment and want to build serious audio gear, go buy a book that at least addresses the issues involved. This is just a 500-page ad for Night Train.
Rating: 
Summary: Ignoble heir to a proud tradition
Review: The history of serious audio amplification-'serious' meaning a concerted effort to achieve fidelity even when mainstream thought held it superfluous-is unusual because, even more so than in Amateur Radio (hams quit building, except for purposely crude and simplistic QRP equipment,in the late sixties for the most part), it has been largely driven by hardcore, soldering-iron-wielding hobbyists. From concert violinist David Sarser to astronaut Norman Thagard, there's a big tradition of bright people wholly outside their discipline plowing new design ground and publishing their results, along with more conventional engineers and technicians whose published works drove first the do-it-yourself builders and then the industry at large. Lincoln Walsh, D.T.N. and Reg Williamson-two unrelated Englishmen twenty years apart-Hafler and Keroes, and many others founded a tradition carried on well into the solid state era: Bongiorno's Ampzilla was the first real stake in the heart of the tube amp's dominance among the hot iron cognoscenti. The "tube revival"-a misnomer because among really serious audiophiles there never was a time where everyone agreed solid state was superior or even acceptable-was, as a previous reviewer notes, a DIY-spearheaded effort with the indefatiguable Ed Dell's Audio Amateur/Glass Audio/AudioXPress magazines and later hardcore journals such as Sound Practices and Vacuum Tube Valley publishing projects, offering parts and describing the finished homebrews in glowing (no pun intended) terms. By no means was solid state abandoned, but tube amplifiers have always been more popular as homebuilt projects.
Many books have been written in the past 50 years on the building of high fidelity equipment. This one isn't the worst, but that's no excuse: it's certainly not very good. It's an unedited, disjointed bunch of facts, half-truths, outright sour grapes, and willfully misleading statements coupled to some projects with PCB artwork but little design explanation. The designs themselves look like they are straight out of Audio Amateur or Practical Wireless (UK) circa 1982. Combined with the author's Howard Cosell-like writing style and total lack of fact checking (he lists the manufacturer of Audio Precision audio test equipment as Thurlby Thandar, a Brit company about as far from Beaverton, Oregon as could be imagined!) he's far more likely to provoke High Enders to chuck the book into a river than to change their mind about anything whatsoever.
His later book is a little better, but not a lot. There are better writers working for far better publishers with far more useful things to say for anyone actually wanting to build an amplifier, so my advice is to simply avoid this book in favor of several other titles. In recent years, speakers of Japanese, German, and even French have had more quality titles to choose from than the Anglophone press has produced-Reiner zur Linde and Isamu Asano especially are most talked about-but none the less, Slone is not a preffered choice in any language.
Rating: 
Summary: No nonsense; highly recommended.
Review: ... Randy Slone regurgitates no one; he states in his own words, clearly and in accessible language for the non-specialist, established principles of solid state amplifier design, and places these in the context of his suggested projects. One chapter is devoted to twelve "ready-to-construct" cookbook designs, and full-size PC board artwork for several of these are provided in an appendix. In short, if you want to build and/or design your own audio power amplifiers, this is an excellent resource.
Randy Slone begins with the basics of acoustics relating to audio power amplifiers and methodically walks the reader through a variety of designs, ranging from old to new, and simple to complex. As one would expect, much of this information is founded upon well established research. There is also a significant portion devoted to new techniques and principles of amplifier physics which help to de-mystify amplifier operation and provide pathways to improved performance. Unlike many similar textbooks that focus on only one topology or design philosophy, Randy Slone examines the broad range of amplifier configurations and power capabilities, including mirror-image input stages, fully-complementary VA stages, paralleled output stages, and lateral MOSFET designs.
Randy Slone may be somewhat opinionated, but his opinions appear to be logical reflections of measurable facts; and as any good scientist knows, that what cannot be measured does not exist for the world of science and engineering. He makes short shrift of tube cult; these are devices that produce measurable distortion and can never compete with the power capacity of modern solid state systems. The writing style and technical descriptions are easy to follow although a background in electronic fundamentals is helpful. No more than high school algebra is needed. Occasional humor increases the reading pleasure. Randy Slone has the somewhat eccentric habit of discussing current flow as if it traveled from negative to positive pole, while the convention is to describe it moving the other way. Once the reader becomes accustomed to this way of thinking - not too silly for electrons do indeed travel from negative to positive - it becomes easier to read. It is a complete resource for designing and constructing your own high-quality audio power amplifier systems.
I am currently building myself six of Randy Slone's OPTIMOS kits after reading the book. The fact that Randy Slone also sells the kits from his web site is a highly positive feature. Imagine trying to source all those components and make the PCBs yourself. Furthermore, Randy Slone is always available to help with specific questions and suggestion on a one to one basis. He really does answer his e-mail.
Highly recommended.
Rating:
Summary: A large poor book written around a small fair one
Review: As a DIY guide for building class-B solid state audio power amps, this book has some merit. However, the author takes a great deal of space to attack the high-end audio business, denigrate vacuum tubes, and denounce "audio subjectivism". There are those who will consider these worthy goals, but even they wil be disappointed in his eighth-grade forensics as he sets up strawmen with little facility. His foreword clearly brings to mind William Burroughs' famous comment on which people, should one elect to do business with them, you should get any statements they make in writing! If for some reason you want to etch circuit boards and fabricate heatsink assemblies to build a type of amp you can buy from Crown or Peavey for less than the parts would cost a hobbyist, Slone's book is somewhat useful. His presentation of the theory is less comprehensible than that of Douglas Self, and assumes a reasonable amount of solid-state theory and the basics of feedback and stability, which many project-oriented hobbyists will lack. However, there are numerous better works on the theory and practice of solid-state amplification,should one wish to repair them or actually design one, and any discussion of the respective merits of solid-state versus tube amplifiers in audio service still starts with Russell O. Hamm's definitive JAES paper, "Tubes versus Transistors: Is There a Difference?". It's interesting that Slone does not cite or acknowledge this document anywhere in this book, or in any other. It's worth noting that although there are many solid state amp designs hobby builders have constructed with excellent sonic reviews-published designs by Nelson Pass and Norman Thagard as well as clones of Quad and Krell commercial amps-probably twenty times as many tube amplifiers as solid-state are constructed by American hobby builders each year. I have built both and had success with both, and surprisingly, having started in hobby construction as a hard-core tube obsessive, I now think solid state has the edge. Slone's book, ultimately, does the case of solid state little good. Tube amplifiers are easier to build for most hobbyists, easier to fix, and their sonic flaws are invariably more euphonic than those of solid state amplifiers: solid state takes a lot more discipline to get right. By denying these obvious facts, Slone puts tube buffs in an even more confrontational position, which does no one any good.
Rating:
Summary: An excellent text
Review: As a former student of electrical engineering, specifically analog amplifier design, I can honestly say that this text is invaluable to anyone wishing to explore the realm of high power amplifier construction.
Rating:
Summary: Only good for electronic engineers
Review: As a learning audiophile, thought this book would give me some electronic knowledge. WRONG, book is useless for anything less than an electronic engineer. Schmatics lost me. Author has an ugly attitude about tube gear. Author contradicts every audio specification I have every learned, may be right, but hard to believe a single voice.
I purchased this book in October, 2001. My copy now on sale ...
Hope it will be a valuable reference for your library.
Rating:
Summary: A presentation of the latest in low noise amplifier design
Review: Audio amplifier design has been cluttered with many esoteric, opinionated approaches to designing what "sounds" best rather than the correct, scientific process of aiming for the best possible design in measurable performance terms such as: stability, efficiency and sonic accuracy. This is a main theme of the book - high quality amplifier designs without the need for theories that border on the superstitious. It seems to be based on the Audio Power Amplifier Design Handbook from Douglas Self - which in itself is a great book and has a few examples. Mr. Slone's book takes the mathematical and electrical theory and presents it in 12 designs - complete with schematics, PCB artwork and a walk through of each. Each one is also offered as a kit from the author. If this is not enough, and as I had read in another review - Mr. Slone invites you to contact him and discuss the projects or the book. I have contacted Mr. Slone and found him to be very helpful and informative, even with projects not related to his book. All in all, anyone interested in building a functional, quality audio amplifier for musical instrument, professional, or domestic Hi-Fi applications and using the latest state of the art design theory is recommended to buy this book. There are no gimmicks to these designs, but they are not limited in terms of features (at least one design has a full set of status LED's!). Highly recommended.
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