The S-shaped horn first appeared on EMG gramophones with the Mark X in 1929. The Mark Xa, which appeared late in 1930, had a 28-inch diameter horn, and the Xb (late 1933) measured 29.5 inches acros the mouth. There followed (in 1935) the Mark Xb Oversize, at 33.5 inches. EMG acoustic gramophones were available into the 1940s.
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