the increase in playing time is made by reducing the lateral speed of the needle across the surface of the cylinder.Although all machines he made after this era were capable of playing the newer, longer records, he also offered conversion kits to retrofit earlier models. until superseded by a blue celluloid material in 1912.Moreover, the celluloid Blue Amberol four-minute records these machines played competed favorably with the three-to-three-and-a-half-minute playback provided in a ten inch disc record.Despite the advantages and historical connection to the cylinder record at the Edison factory, the disc record was a much more convenient form of media. that derive from period sales literature and model designations.The disc record could be more cheaply stamped, easily stored, and offered two sides to a single record, meaning a sales advantage and more profit per record. The Diamond Disc players used vertically cut records and could not play thin 78 rpm records without a special reproducer attachment. : a highly successful sales technique to help impart the allure of Edison's research successes to such a modern musical device. Columbia's sales approach was to produce a variety of very cheap phonographs that would compete favorably with the other makers, and thereby boost sales of their more profitable sector: the records.
Disc phonographs grew in impact throughout the 1900s and 1910s, and by the 1920s were very common and produced in large quantities. Cases were usually oak, and the cast iron parts enameled black with gold or gold-and-blue pinstriping or decals. Such horns were not self-supporting but needed a steel support crane to suspend them in front of the phonograph.
Other important differences are noted in the method of sound reproduction: cylinder records and Edison Diamond Disc records (and some other disc records made by other manufacturers) are considered "vertical cut" records because the rounded jewel point (stylus) of the reproducer vibrates up and down as the groove passes under it. Although this is far from a comprehensive view of an industry that offered a huge and always changing complement of products at the time, similar to today's computer industry, it does indicate that significant differences could exist between any two vintage phonographs, even they if are from the same producer or year.
Indeed, many phonographs look very much alike unless you pay great attention to the minutia...
As technology progressed, Edison was able to double playing time to four-minutes in 1908 by decreasing the thread width by half.
A record playing 2 minutes versus 4 minutes spins at exactly the same speed ?