In 1933 in Brno he conducted the world premiere of the ballet Svatba, set to Stravinsky's Les noces, choreography by Máša Cvejicová.

It is clear from the markings on the scores held there that Sachs dispensed with the practice of linking scenes in the opera by way of extended interludes.

[10] During World War II, as a Jew, Sachs converted to Catholicism in an attempt to save himself from persecution by the Independent State of Croatia regime.

For a time he was sheltered at the ward of ophthalmologist Dr. Vilko Panac in the Sisters of Charity Hospital Zagreb.

[11] He was President of the Croatian Society of Music Artists 1945–48, and he was instrumental in the development of the Zagreb Opera after World War II.

He was also known for his work in the concert hall, particularly in the symphonies of Beethoven, and Smetana's symphonic poem cycle Má vlast.