Audio disc analog timeline

Date	Description	Notes
1888	Berliner experiments with acid-etched zinc discs.
1889	Toy gramophone. Five inch celluloid or hard rubber discs.	Prior to 1900 discs were pressed from stampers formed from acid-etched masters.
1894	Berliner player launched. Hard rubber discs.	The early Berliner discs played at 70 rpm. From 1900 to 1925 playing speed hovered between 74 and 82 rpm, then became stabilised at 78 rpm with the introduction of electrically powered turntables.
1897	Shellac discs.
1900	Wax masters supercede acid etched zinc masters.
1925	Electric recording supercedes acoustic recording.
1932	Lacquer discs allow instant replay after recording.	Mainly used by broadcasters.
1948	Microgroove Long Play vinyl discs. Ten and twelve inch at 33.33 rpm.	A small run of coarse groove 78s were pressed on vinyl in 1946. Apart from that run 78s were nearly always made from shellac. The 33.33 rpm speed was used prior to LPs by the broadcast industry on 16 inch coarse groove transcription discs. The advent of microgroove allowed the same playing time on 10 or 12 inch discs.
1949	Seven inch 45 rpm microgroove vinyl.
c1960	Last shellac 78s produced.