Nobody has any doubt that valve amplifiers produce a remarkably beautiful sound. They have a lively, deep, clear, and expressive sound, and dynamically they do not appear to have any limitations. The author investigates, in a systematic theoretical approach, the reasons for these beautiful properties. He develops new models for power valves and transformers, thus enabling the designer to determine the properties of the amplifier during the design process. Mathematical models for the coupling of power valve(s) and output transformer are provided. These will generate new insights in a special kind of distortion: the dynamic damping factor distortion (DDFD). With mathematical models in the complex domain, especially the properties at the limits of our hearing range (from 20 Hz to 20 kHz) are investigated and the minimal stability criteria for the amplifier are formulated. The often-applied negative feedback in amplifiers is extensively modelled and discussed in relation to our hearing appreciating. And after all this theory a fine selection of special amplifiers is presented and discussed. You will notice in this book that the author not only writes about amplifier technique, but tells about the way the development of valve amplifiers can have an influence on your daily life; even the usefulness of patents is discussed. Summarizing: new theories and solutions for perfect audio with valve amplifiers. Not only the professional and the DIY-er but everyone who wants to understand valve amplifiers will read this book with much pleasure.
