The Valve Wizard

Hardback, 233 pages.
OUT OF PRINT

Attention:
I'm sorry to say this book has been removed from print. I will probably write a second edition eventually, but it could take years. This book is therefore unavailable until further notice. Do not email me asking if I have spare copies or PDFs; your email will beignored.

The power supply is the most important part of any audio amplifier. Ultimately, everything you hear through the speaker begins life in the power supply, yet information on the design of this part of the amp is patchy at best. Well, until now that is...
This book is the world's first comprehensive guide to the design of power supplies specially for valve equipment. If you have ever asked:
How do I choose a power transformer? How much voltage does a valve rectifier really drop? Do I need a standby switch? Is there a better way to design a bias supply? How do I design a DC heater supply / high-voltage regulator / audio power control?
All these questions -and many more- are explored in detail Not only is it a gold-mine of hard-to-find information on the more subtle nuances of design, but it comes with a small price tag, too!

Synopsis: Designing Power Supplies for Valve Amplifiers is a unique guide to the operation and practical design of linear power supplies, especially for valve equipment. Audiophiles, guitarists and general hobbyists alike will find this book an invaluable source of detailed information on transformers, rectifiers, smoothing, high-voltage series and shunt regulators, and much more.
Although this book is not intended for the beginner, learning is encouraged through practical design, and concepts are introduced at a basic level before the reader is accelerated to the stage of high-performance design, with over 200 circuit diagrams and figures. Numerous practical circuits are included, for high-voltage stabilisers, heater regulators, optimised bias circuits, high-voltage supplies using 'junk box' parts, and even audio power control for guitar amplifiers. An essential handbook for any valve amplifier enthusiast!

Read the first chapter for free here.
View book contents here.

Errata:
On page 3, the equation for inductance should of course read: E=L di/dt. Similarly for page 4.

In chapter 8 (bias supplies) there is an error in the universal bias supply shown in fig. 8.1. The corrected circuit is shown below. R3 allows C2 to discharge slowly at switch off, or when adjusting the bias pot. The time constant of C2*R3 might be set in the range of 1 to 3 seconds, say 10uF and 100k. This correction should be applied to all other instances where the discharge-reduction diode is shown (i.e, figs 8.2, 4, 10, 11 14). Apologies for any confusion this may have caused!

In fig. 8.11a (page 185) the reservoir capacitor in the auxiliary bias supply has the incorrect polarity and should be reversed.

In chapter 10 (voltage control) there is a modification that should be made to the bias tracking circuit in fig. 10.22 to protect it against possible oscillation. A 220pF capacitor should be added between base and collector of the pass transistor, as shown in red.