This updated, augmented third edition is aimed at hobbyists, students, engineers, and others who would like to learn more about the design and operation of electronic circuits used by guitarists. This book presents accessible qualitative and quantitative descriptions and analysis of a wide range of popular amplifier and effects circuits, along with basic design techniques allowing the reader to design their own circuits. The new edition further includes several additional circuits and topics suggested by readers of the previous editions, including noise gates, analog multipliers, the effects loop,  and additional tube amplifier design examples.