William Sinkler Darby

Early recording engineer (born October 8, 1878 in Fort Motte, South Carolina, USA – died December 15, 1950 in Baltimore, Maryland, USA).

Between 1895 to 1899, W. Sinkler Darby served as an assistant to The Gramophone Company Ltd. ("His Master's Voice") in whose Recording and Research Department he worked for the next 25 years, recording artists around the world.
In 1924, he became Technical Manager of the Recording and Research Department of the American Brunswick Company.

Between 1899 and 1904, Sinkler Darby marked his recordings with the suffixes
A (Zinc 7"), B (Wax 7"), X (Wax 10"), Y (Wax 12").

After 1904, Sinkler Darby marked his recordings with the suffixes
g (7"), h (10"), i / j (12"), and
ae (10"), af (12") - only between 29.02.1916 and 18.04.1916.