Vacuum Tube Amplifier Basics

by E.J. Jurich

There is a growing number of audio enthusiasts and hobbyist interested in creating their own vacuum tube amplifiers. If one has the necessary technical information, high quality tube amplifiers can be assembled. Although it is true that accurately calculating electronic circuits can involve complicated formulas, for the electronic hobbyist it is not necessary to perform at the level of an electrical engineer. With some basic knowledge, it is possible for the hobbyist to design and build vacuum tube audio amplifiers that perform well. For the novice not versed in electronics, several sections of the book cover electronic basics that pertain to vacuum tube circuits. Includes Ohms law, voltage, current, power and watts. Explains capacitors, series circuits, parallel circuits, voltage dividers, reading circuit drawings plus other related information. Principles of vacuum tube operation voltage amplifiers and power output are explained. Includes function of grids, effect of tube capacitance, tube resistance, heat dissipation, bias, miller effect and calculating voltage gain. A table of component values for the popular 12AX7 in various operating parameters simplifies pre-amplifier stage design. Power supply sections cover vacuum tube and solid state rectifier conversion of AC to DC and DC filtering. Amplifier design example takes you through the steps of designing a single ended ten watt amplifier with volume and tone controls. Working with electronics and vacuum tube circuits requires some math. Circuit calculations in this book use various forms of addition, subtraction, multiplication and division. Formulas are all solvable using a standard 12 digit calculator (requires a square root key). Calculations are presented with examples. Project layout circuits include a line amplifier with 25db gain, triode balanced-unbalanced input stage, tone control stage, turntable pre-amplifier, 6V6SE Class A stereo amplifier, 6V6SE Class A monoblock amplifier, 30 watt monoblock amplifier and a basic 5 watt guitar amplifier. The 30 watt monoblock amplifier is designed for tube rolling using various type output tubes.

Genres: Music

210 pages, Paperback

First published June 15, 2013

Reviews

[EJ Jurich · Rating 5 out of 5]

The newer second edition is available on my website in PDF format: PDF eBooks are readable on just about any device. PDF content remains fixed, presenting content like a printed book. This second edition of the book has much of the original book with the addition of a more detailed example of designing and building a vacuum tube amplifier. The book begins with 110 concise reference pages covering technical information that pertains to vacuum tube circuits. Includes basic electronic circuit functions. For the electronic hobbyist, it is not necessary to perform at the level of an electrical engineer. Circuit calculations in this book use various forms of addition, subtraction, multiplication, and division. Formulas are all solvable using a standard 12-digit calculator (requires a square root key). The amplifier design example takes you through the steps of fabricating a traditional chassis layout and designing a Class A stereo amplifier. Front covers of the old print books may make reference to different revisions; they are all basically edition one with some updates. The current second edition was carefully assembled over several months and is less expensive than the original print versions. In addition, images in the old print books were all black and white. Several images in the new second edition are in color, including the project layout drawings at the back of the book. Purchased and downloaded directly from my webpage, for the electronic hobbyist, I feel this is one of the best vacuum tube amplifier technical book values available. ejjurich.com