The definitive academic and practical resource on this subject is by Morgan Jones . This work is widely recognized as the industry standard for both hobbyists and audio engineers, covering everything from basic theory to advanced construction and testing. Key Resources & Papers
: Often used as a companion to the above, this book provides deep technical analysis, maintenance guides, and rudiments of electronics for valve design. It is available at the Elsevier Shop . Building Valve Amplifiers
Building a valve amplifier generally involves several critical stages as detailed in the literature: The definitive academic and practical resource on this