A great infromation source and reference to valve/tube amps,
This review is from: The Tube Amp Book (Spiral-bound)
Aspen Pittman of Groove tube fame puts together a comprehensive book examining valve amps for guitar and bass, at same time being both a historical reference and technical resource. The first half of the book is split into a historical A to Z of the major guitar/bass valve amplifier manufuacturers and a technical section covering potential modifications and comprehensive valve data sheets.
The second half contains an A to Z of many amplifier circuit schematics from "Ampeg right through to Western Electric and a CD with a total of 600 schematics! Although the book at times turns into a Groove Tube sales brochure, you can forgive the author as the information contained is also quite useful.