Customer Reviews

Designing Tube Preamps for Guitar and Bass

5 star:		(17)
4 star:		(2)
3 star:		(1)
2 star:		(0)
1 star:		(0)

 

 

I believe Merlin Blencowe's work occupies a hitherto unoccupied place amongst books on the subject of valve musical instrument amplifiers - I own quite a few on the subject. This book is sure to endure.

Classical electronic texts from the fifties and earlier occupy one extreme of the spectrum and repair and modification cookbooks the other end.

I find the book well compliments Richard Kuehnel's excellent treatises. Both Blencowe's and Kuehnel's sit closer to the classic texts in approach than say K O'Connors books. Due to Blencowe's inclusion of solid examinations of the sonic implications of various design choices, this book tends more toward immediate practical application than Kuehnel's books do. Blencowe does the latter task better than any other text currently available, it really does integrate theory and sound. The book also contains original research and observations, notably on the dc coupled cathode follower.

If forced to recommend any one book for those interested in guitar preamp design it would be this one. But then again, who, if they were genuinely interested, would make do with just one book?

F Langford Smith, F Terman and other great technical and academic authors from the past are put into modern context by Kuehnel and Blencowe. In fact, these four authors together cover the entire theoretical field needed. Never before have guitar amplifier designers and hobbyists had so much high quality, well-written field-specific information at their fingertips.

I look forward to future editions from Mr Blencowe.

This is bar-none the best book available on the subject. For anyone with more than a passing interest in tube amplifier design for musical instruments, this is a must-have. The language is clear and accessible, and the mathematical treatment distilled to a level that is practically useful, without being overwhelming to non-electrical engineering types such as myself. Besides clear descriptions underlying the design of several key amplifier circuits, it also lays out best practices in a number of areas, and there is also a great deal in this book that is just downright innovative. Indeed, it provides a treasure trove of ideas that amply repays repeat reading. Very highly recommended. I'm very much looking forward to subsequent volumes.

This book is not meant for beginners, but if you are designing a tube amp, you're probably not a beginner in the first place. It is not a long mathematical treatment of design. The math is there, but all the long derivation calculations are crunched down to a few steps (you can get the full mathematical treatment of the same calculations from the old electrical engineering texts). This book is about applying the design ideas and using the final math formulas.

Most books on guitar tube amplifiers approach them from the same angle as a Hi-fi amplifier. Musical instrument amps are different from Hi-fi amps. Guitar amplifiers are meant to produce distortion, even "clean" amps. This is not just another re-writing of all the amp design books from the 40's and 50's, it is very specific in its scope and does it a clearly written style. There are schematics and graphs that really do help you inderstand better and not just fill up the page count.

It's all here from a basic gain stage to interstage coupling, tone stacks, cathode followers, feedback, effects loops, and phase inverters.

If you are past building kits and want to know how to make it all work with your own ideas, this is your book.

This book is perfect for any DIY tube guitar or bass amp builder who's built an amp or two, but still isn't quite sure why everything works the way it does, or who wants to design his (or her) own preamp.

It can be very frustrating finding tube theory articles, books or websites that are both accurate and readable. This book is both.

It assumes some basic electronics knowledge - military or technical school level is fine, though EEs will also get the info they need without over-simplification, as is found in some other books. All the formulas are here, along with clear explanations of how and why to use them.

This book is the only one I've read that gets into the details of tone shaping and distortion generation in modern preamp design, and it's backed up with nice schematics and photos of scope displays, as well as full references if you want to dig in even deeper.

There is also a chapter of valuable practical tips and building techniques.

I think this book will become a standard reference for tube amp builders - I couldn't recommend it more highly.

I own or have read most of the available books on vacuum tube amplification. While they all contain some useful information, there are not many I would consider indispensible. This book falls into that category. This book does not focus on the tonal differences between mustard vs. orange drops, or NOS vs. new production tubes. Nor does it offer descriptions of the features of classic amp circuits. There are plenty of books that do this already.

What this book does it to take you through the design of a circuit from beginning to end. Other books may tell you that the 5F6 Bassman uses a "long tailed phase inverter" and show you a schematic or layout. Merlin shows you how all the major phase inverters work, then takes you through the design of each type of phase inverter. All the calculations used for part selection are laid out in a straight forward manner. The pros and cons of each inverter type is explained. There are no unsubstantiated blanket opinions here.

The formulas may put some people off, but unfortunately, they are necessary if you want to modify or design amp circuits. This book does a far better job of presenting technical material than the Radiotron Designer's Handbook. In my opinion, the problem with the RDH is that it is not written for guitarists. In fact, the electric guitar was not even invented when my the version of the RDH that i own was printed! In this book, after going through the operational aspects and design of a circuit type, Mr. Blencowe will then often show an example of how the circuit is implemented in a well known amplifier. To me, the context is an important link that enables me to associate a circuit with something I have heard before.

The format of the book is similar to the material at Merlin's valvewizard website. There are no glossy color photos of amplifer gutshots, nor are there reams of schematics and layouts for popular amplifiers. There are many graphics in the book, mostly falling into 3 categories.

1. Circuit diagrams showing the components, voltages, etc.
2. Oscilloscope traces showing how a particular vacuum tube responds to a change in load or screen resistor, or how different distortion types manifest themselves in the signal waveform.
3. Sample layouts for circuits

Finally, this is of of the few amp books that I have read that I have used to implement design concepts. Specifically, I am "bootstrapping" the cathode follower and using "diode biasing" for the first preamp stage in the amp I am currently building. Both of these ideas were lifted right out of this book. If you are interested in getting beyond the "paint by numbers" method of building amps and want to design your own amplifier, or modification to an existing amp this book is on the short list of amplifer books that is indispensible.

As yet, I have not bought the companion book on power supplies. It is definitely on my list, however.

After building a few effect pedals and an amplifier kit, I've decided to get more intimate with how things work inside a tube guitar amplifier. I've tried Internet forums, free (old) books available online (army training books, Jack Darr's book), borrowed and bought various material. The information I got tended to fall into extremes: either pretty-packaged-many-lovely-pictures "tubes for dummies" type-books, or the "before we go any further we must learn how to split the atom" kind. Add to this the bona-fide misinformation gladly served by anyone with a keyboard and something to prove on Internet forums, and the never-ending fights between people who prefer Mallory 150s to current production Orange Drops, and you've got yourself at least a mild headache.

Enter Merlin Blencowe's book. After reading some of the information that the author generously provides for free on his website (the full first chapter of this book included, look up "valve wizard" for the website), I've decided that I'd like to read more, so I bought the book. Turned out to be the best money I've ever spent on a technical book. It won't teach you what a capacitor does, but it won't assume that you're a professional or that you're interested in all the tube types since tubes were invented. One of the strongpoints of the book is that it finally bridges the gap between the cold hard facts about the circuits (that the engineers prefer), and the subjective description of how different component values and circuit topologies influence the elusive TONE of a guitar or bass.

If you're serious about knowing how and why your tube amplifier works, you understand basic electronic theory and want a book that gets straight to the point, no mathematics beyond what you should know for hands-on work, and sticking to what you can build with TODAY, you should get this book. If you can only afford one technical book about guitar tube amplifiers, make it this one (don't take my word for it, the well-respected tube amplifier builder Randall Aiken seems to concur).

As for the book only covering the preamp part of an amplifier - that's the most important part. "The attentive reader", as the author likes to say, will be able to understand the power section of a simple SE amp with a 6V6 power tube, for example, by reading carefully the section about preamp pentodes, the free information on Merlin Blencowe's website about power tubes, and the 6V6 data sheet.

Shop around for the best price for this book, but whatever you pay for it I can't imagine anyone being dissapointed with the purchase. And mr. Blencowe clearly deserves the sale.

Thank you for the hard work, mr. B!

It's a little expensive but worth it, the only book you'll need for preamps. Covers all the well known circuits and how to improve them, or use the formulas to design one from scratch, or use one of his suggestions, there's plenty to choose from. Gets very technical with mind exploding math but keep going, it will make sense. If you want to design or build guitar amps, this book will add greatly to your understanding of how tone is achieved with tubes.

Once you know enough about electronics this book becomes THE source of reference. It is not for beginners, but you also don't need an engineering degree to understand the concepts.

Kuehnel's books are another good source, but IMO not as good as this one. The O'Connor book(s), while still good, a distant third.

Great book with enough to learn to make it worth buying. I almost returned it because there is alot of math and electronic engineering formulas and derivations. I decided to keep it because in between all that are excellent explanations, real-life examples and practical data.

I have so far only skimmed though the entire book as I got it today, but I can see, in comparison to all the other similar books I have, the material is explained in a very comprehensible and practical manner. I want you to know I own almost every guitar amp book and series out there, and there is always something to pick up, or read about another view, idea, or suggestion. Guitar amp authors range from history lessons, ego trips, myth, voodoo, their practical knowledge based on their expediences, to involved complex math that in the end one might say OK, what do I do with this information? While another author will just state here is how and why without any complex explanation. I am a guy who wants to know why and have practical information. Some other books I have are still on the shelf for a more though read and study when I have more time as the immediate payoff, other than going to specific sections as I need them, is just not there. If you are an amp designer (even if you wrote a book yourself) or built a few tube amps, or plan to, this book is one you should have. Even if you don't design an amp, you will have a better understanding of designs. This is not a coffee table book, but a book amp techs, builders and designers would enjoy. Looking at all the books I have, I see them as documenting a lost art, that at some point will be harder and harder to obtain. I am not the type to beg for answers on the internet but to read and learn. This is a wonderful book chock-full of useful information that I wanted in my library, and I did not want to risk not being able to get at some point. There is not a big market for such books, and sometimes great books disappear (though this one is print-on-demand/small stock on-hand book). With free shipping, AMAZON was indeed the place to buy it when it came down to cost, speed and reliability.