Blue Amberol Records
The early Blue Amberol releases offered excellent audio quality for their era — better, in fact, than later issues, because from January 1915 onward Thomas A. Edison, Inc., which had been concentrating its efforts on improving the quality of Diamond Disc phonograph records, began to release cylinders which were acoustically dubbed from Diamond Discs.
Beyond the main popular and sacred music series, which began with record number 1501 in 1912 and ended with record number 5719 in 1929, Edison offered a special line of prestigious Concert Blue Amberols of opera arias, light classical pieces, and other "cultured" music performed by "name" artists, later supplanted by the distinctively tinted Royal Purple Amberol cylinders.
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.
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.
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.
This core is proving to be problematic for the long-term survival of Blue Amberol Records, as the plaster often tends to expand over the decades, especially if exposed to moisture or kept in humid conditions.
In moderate cases, swollen plaster can make the record not fit properly on the phonograph mandrel (this can be fairly easily remedied by gently reaming out the plaster to restore the correct inner diameter) or can warp the cylinder out of round, making it not play properly.
In worse cases, the expanding plaster will crack or split the plastic playing surface, rendering the record unusable.
