Born in Yorkville, New York, of Hungarian heritage, Kardos learned to play the violin and saxophone and worked in vaudeville pit orchestras until organizing his first band around 1930.
A New York territory band, its usual home base was the Gloria Palast, a German-American ballroom and café on East 86th Street in the Yorkville neighborhood.
Due to the location of AFM Local 802 headquarters nearby, many music professionals caught Kardos's band.
Among his musicians were Hymie Schertzer (sax), Vic Schoen (trumpet, arranger), Joel Shaw (piano), and Bernie Green (arranger-composer).
Disbanding in 1939, Kardos married and took employment with the postal service in New York City by day, while leading a small café-style band evenings at Zimmerman's Hungaria, a popular restaurant in Yorkville.