A Tiny History of High Fidelity Parts 1 & 2 by Lynn Olson.
http://www.nutshellhifi.com/library/tinyhistory1.html
http://www.nutshellhifi.com/library/tinyhistory2.html
http://www.nutshellhifi.com/library/tinyhistory1.html
http://www.nutshellhifi.com/library/tinyhistory2.html