Sano was formed as an accordion company in 1951 in New Jersey by Nick Sano, an accordion player; Joe Zonfrilli, an electronics technician; and Lou Iorio (Zonfrilli's brother-in-law) a music teacher.  Stanley Michael provided electronics consultancy services to Sano but was not officially part of the company. Michael developed an accordion pickup for Sano around 1951 and in 1953 Jack Gentul joined the company as an electronics designer. From 1953 until 1964 Gentul designed the circuits for all Sano's tube amplifiers. Being primarily an accordion company Sano's tube amps were initially voiced to fit accordions and vocal microphones but soon they developed amps for guitars as well. Sano mainly made amps under their own brand name, but they also made  Hohner and Excelsior branded amps. Sano amps are developing a reputation as an affordable option for great vintage tone. Sano also sold guitars - these were imported from Italy and Japan.

Source: Premier Guitar: 7 sleeper vintage amps that bring the noise. July 2017

Source: Hilgen Amplifiers - Jack Gentul the genius behind Hilgen (11 December 2017)