I own the first edition (and later) of the book whose cover time is the one displayed in this topic, for a very long time it was changed to be more current and more meaningful. The edition was in 2000, when Internet was just beginning to exist. The book helped me at the time because he wanted a sort of directory of schemas at a time when we were nowhere. The book and its author says clearly had no reason to exist in this form since the existence of technical material on the net, so it was completely redesigned a few years ago and now has only 132 pages talking about the operation of each component and their roles in an extremely detailed, with examples of good teaching and clear as visual diagrams, how to make its circuit perso.Tout is explained in clear so that even a novice can understand without difficulties. If the field of electronic circuits and their guitars and hacking interests you, this book is perfect and it's a safe bet.
http://www.kcpi.fr/pdf/SOMMAIRE&EXTRAITS_G&BC.pdf
http://www.kcpi.fr/pdf/EXTRAITS_GUITAR_CIRCUITS.pdf
Conclusion: great book and I did well to follow in these editions update.