The field, of application of audio amplifiers is continually growing.
This applies not only to gramophone and microphone amplifiers, but also to tape and wire recorders, amplified stringed instruments, modulation amplifiers for transmitters and so forth.
For all such applications excellent factory made amplifiers are obtainable, but it is nevertheless a fact that many prefer to build their own.
It is for these constructors who not only include the more or less professional designer, but also the amateur who builds amplifiers for interest’s sake, that this book has been written.
A.F. amplifiers are often built with the aid of a publication describing a certain circuit and containing a more or less complete wiring diagram which, if copied faithfully, will give quite reasonable results.
Whenever unusual features are required, however, the cut-and-dried design no longer meets the need.
The construction of an amplifier becomes a far more interesting task if it can be done without a wiring diagram, an efficient amplifier being produced with the aid of a circuit diagram only.
The designer is then not tied to a rigid layout, and the circuit can, if desired, be modified.
Parts of any one circuit can be incorporated in another.
When certain components are available, it is possible to see how far they can be utilized and the circuit modified to accommodate them, this being a procedure to which the amateur often has to resort for financial reasons.
The aim of this book is to enlarge the knowledge of the reader and to stimulate him to experiment for himself.
It accordingly contains general hints on amplifier design, the uses of valve data, the functions of the different stages of an amplifier, and concludes with detailed descriptions of eight amplifier designs, in which will be found a wealth of practical data, measurements and interesting new features.
The treatment of the subject matter is directed entirely towards practical achievement, and all theoretical considerations and arguments have been omitted.
Those who, encouraged by the contents of this book, wish to increase their knowledge, are recommended to read the well-known Philips series of books on electronic valves, especially.