Book excerpt: Practical Audio Amplifier Circuit Projects builds on the introduction to electronic circuits provided in Singmin's innovative and successful first book, Beginning Electronics Through Projects. Both books draw on the author's many years of experience as electronics professional and as hobbyist. As a result, his project descriptions are lively, practical, and very clear. With this new volume, the reader can build relatively simple systems and achieve useable results quickly. The projects included here allow a hobbyist to build amplifier circuits, test them, and then put them into a system. Progress through a graduated series of learning activities culminates in unique devices that are nevertheless easy to build. Learn the basic building blocks of audio amplifier circuit design and then apply your knowledge to your own audio inventions. Targets the intermediate to advanced reader with challenging projects that teach important circuit theories and principles Provides a ready source of audio circuits to professional audio engineers Includes an electric guitar pacer project that lets you "jam" with your favorite band!