Vacuum Tube Amplifier Basics

EJ Jurich 2014

It is true that accurately calculating electronic circuits can involve complicated formulas, but 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. This book covers basic electronics related to vacuum tube amplifiers, an elementary reference guide for the novice working with vacuum tube amplifier circuits. Written in sections that are concise, many with examples and illustrations. Sections help you read at your own pace, convenient to stop after a section, skip around sections or refer back to a section. For the novice not versed in electronics, electronic principles are included along with several sections covering electronic and audio basics. Vacuum tube amplifying circuits are explained in simple terms without complicated math. Math is primarily basic math and a few simple formulas all solvable with a standard calculator and presented with examples. Principles of vacuum tube operation includes function of grids, effect of tube capacitance, tube resistance and heat dissipation. Power supply sections cover vacuum tube and solid state rectifier conversion of AC to DC and DC filtering. A sample power supply is used to explain calculating loads, determining required transformer ratings and component values. How to calculate a primary fuse value is also explained. Includes bias, bias supplies, calculating voltage gain and more. A table of component values for the popular 12AX7 in various operating parameters simplifies amplifier stage design. Includes project circuits with parts list and component layouts for a Buffer Line Amplifier with 25db gain, Triode Balanced-Unbalanced Input, Tone Control Stage, Turntable Pre-Amplifier, 6V6SE Stereo Amplifier, 6V6SE Monoblock Amplifier and a 30 Watt Monoblock Amplifier designed for tube rolling using various type output tubes. Also, included is a Guitar Amplifier project.