Michael Soldano originally worked with technician Bill Sundt at Stars Guitars of San Francisco, modifying amps brought into the shop.

Soldano built his first amp, a Fender Bassman clone, with the aid of books discarded by a library.

[1] Soldano gave a prototype to Howard Leese of Heart while working as a roadie to avoid bankruptcy and soon after received orders from Lou Reed, Michael Landau, and Vivian Campbell.

[1] Soldano officially released the SLO 100 in 1987 and sold amps to Eric Clapton and Mark Knopfler,[1] as well as Tommy Kessler of Blondie,[2][3] Joe Satriani, Steve Vai, George Lynch, and Gary Moore.

[1] In 1991, Eddie Van Halen used an SLO 100 (which replaced his Marshall 1959 due to technical issues) for the album For Unlawful Carnal Knowledge and modeled his signature amp, the Peavey 5150, after it.