Stefan Sobell began building instruments in the early 1970s starting with an Appalachian style dulcimer and a carved-top cittern. He became a full time instrument maker in 1975 and added mandolins and bouzoukis based on his cittern design. In 1981 he built his first arch-top guitar, soon followed in 1983 by first flat-top guitar.

Source: Stefan Sobell website (30 June 2023)