When Mike Soldano designed the SLO-100 in 1987 he had no idea that it would transform the guitar amplifier industry, becoming one of the most iconic amps of all time. As we all know now, the SLO became a big hit, particularly in the heavy metal community, backing bands like Dokken, Ratt, and Dio. At Wacken Open Air it is perhaps the ultimate rig-of-death.

This book examines a circa 1996 version of the SLO-100 with an effects loop. The preamp's cascading-gain architecture requires several triodes to implement, but each is dedicated to a pivotal role in the signal chain. With only two channels and a simple switching mechanism, the SLO has a surprisingly compact architecture for creating such a rich palette of tones. The book explains how the amp works, the motivation behind its system design, and the performance of its electronics in the context of a real musical performance.

Richard Kuehnel is a member of the Circuits and Systems Society of the Institute of Electrical and Electronic Engineers.