Born in Hamburg, Ambrosius came via Magdeburg, Berlin and Chemnitz to Leipzig, where he received his musical education.
From 1925 to 1942, Ambrosius was Tonmeister at the Mitteldeutsche Rundfunk AG [de] and since 1926 teacher at the University of Music and Theatre Leipzig.
[2] During the National Socialism period he wrote various cantatas and songs for male choir in conformity with the system in addition to symphonic and concertante music and the Deutschen Landschaftsbildern (1939).
[3] From 1945 Ambrosius worked as a private music teacher, choir leader and freelance artist.
[4] The "Bund Deutscher Zupfmusiker [de]" expressly promoted his work for this field and made him an honorary member.