At sixteen Jan went (in 1963) to work for D.A. Flentrop in Zaandam. He persisted in his championship of the romantic organ in face of the neo-baroque ideals and finally set up his own organ building company in 1967. His first new organ (III/P, 32 stops) was built in Singelkerk, Ridderkerk (NL). Jan also made the richly profiled organ case and wood carvings.