Definição do conceito
[ENG] In late 1908, Edison had introduced wax cylinders that played for nominally 4 minutes (instead of the usual 2) under the Amberol brand. They were made from a harder (and more fragile) form of wax to withstand the smaller stylus used to play them. The longer playing time was achieved by shrinking the groove size and spacing them twice as close together. | ... | Edison made several designs of phonographs both with internal and external horns for playing these improved cylinder records. The internal horn models were called Amberolas. Edison marketed its "Fireside" model phonograph with a gearshift and a ´model K´ reproducer with two styli that allowed it to play both 2-minute and 4-minute cylinders.[18] Conversion kits were produced for some of the later model 2-minute phonographs adding a gear change and a second ´model H´ reproducer. These kits were shipped with a set of 12 (wax) Amberol cylinders in distinctive orange boxes. The purchaser had no choice as to the titles. | SOURCE: https://en.wikipedia.org/wiki/Phonograph_cylinder
==============================
[ENG] Edison Blue Amberols are made of celluloid on a molded plaster core. The celluloid surface is able to withstand hundreds of playings with only a moderate increase in surface noise if played on a well-maintained machine with a stylus in good condition. | Blue Amberols have a maximum playing time of about 4 minutes and 45 seconds and play at the standard post-1902 cylinder speed of 160 rpm. Like the preceding black wax Amberols, they provide twice the playing time of 2-minute cylinders by using a finer groove with a pitch of 200 lines per inch instead of 100. They cannot be played on older machines set up to play only the earlier standard 2 minute cylinders, as both wax and celluloid Amberols require a smaller stylus tip to fit the finer groove and the worm-gear which moves the stylus over the surface of the cylinder must turn at a different rate. Thomas A. Edison, Inc. sold kits with gear assemblies and reproducers that could be installed by the owner of an older Edison machine so that both standard and 4-minute records could be played. The Edison company also marketed new models capable of playing both. With these combination machines the operator needed to adjust a knob or lever that shifted gears and make sure the correct reproducing stylus was in position when switching from one record type to the other. | Internal horn Edison phonographs designed to play 4-minute cylinders were called Amberolas. The earliest Amberola model, the 1909 Amberola IA, was equipped with selectable 2 and 4-minute gearing, and after initially being sent out fitted with an unmarked Model "L" reproducer with a flattened fishtail weight that was recalled almost immediately as being "unsatisfactory", was refitted with the Model "M" reproducer with flip-over 2 and 4-minute sapphire styli for playing wax cylinders. There is at least one known example of an early Model M reproducer also fitted with a flattened fishtail weight. | Upon the introduction of Blue Amberols in 1912, the M reproducer was supplanted by the Diamond A reproducer, which was designed for playing only celluloid cylinders. Its small-tipped conical diamond stylus and increased stylus pressure would seriously damage wax cylinders. External horn Edison phonographs were available with the Diamond B reproducer. Several other Amberola models less expensive than the IA (and later the 4-minute-only IB and III) were available, such as the V, VI, and X. | After an Edison factory fire in December 1914, the Amberola line was simplified in both mechanical and cabinet design, resulting in the 4-minute-only Amberola 30, 50, and 75, each model number indicating the initial retail price in dollars. They were equipped with the Diamond C reproducer. The 4-minute-only external horn Opera (later renamed Concert) model of 1911-1912, which used the same mechanism as the IB and III, was initially fitted with the Model L reproducer, which had an elliptical sapphire stylus for playing wax Amberols, but after the introduction of Blue Amberols it shipped with the Diamond A reproducer. | SOURCE: https://en.wikipedia.org/wiki/Blue_Amberol_Records
==============================
