The Class-A Amplifier Site

This site was last updated on 26 September 2009




The Class-A Amplifier Site



This site is primarily dedicated to the Class-A amplifier designed by John Linsley Hood, which was originally published in Wireless World in April 1969 (with a postscript in December 1970) and later updated in Electronics World in September 1996.  However, other Class-A design articles by Jean Hiraga, James Sugden, Stan Curtis and L Nelson-Jones have been added, along with some more JLH circuits. Schematics for other Class-A amplifiers and for three classic Class-B commercial amplifiers, the NAD3020, the Cyrus 1 and the Sugden A48-II, have been included for reference.





Last Updated

The JLH Class-A Amplifier


1 May 2004

Other JLH Amplifier Designs


12 January 2002

Other Class-A Amplifiers


19 July 2004

Classic Class-B Schematics


17 August 2003

JLH Power Amp Schematics


18 January 2007

The Published Articles of John Linsley Hood


26 September 2009





This website is maintained by Geoff Moss. I can be contacted at:



01/05/2001 Site created

04/07/2003 Site closed

17/08/2003 Site re-opened with new URL

04/04/2004 Indexing revised

18/01/2007 JLH Power Amp Schematics added