Page "Blue Amberol Records" Paragraph 9

Blue Amberols have a maximum playing time of just over 4 minutes at 160 rpm ( a maximum of 4 ' 45 " is possible ).

They can not be played on older machines set up to play the earlier standard of 2 minute cylinders, as the Amberols require a smaller stylus to track the groove and the worm-gear which moves the stylus over the surface of the cylinder must turn at a different rate.

However, the Edison company sold kits with gears and reproducers which could be attached to older varieties of cylinder phonographs by those who wished to be able to play the new Blue Amberol records.

The Edison company also marketed phonographs capable of playing both the older style 2-minute and the new 4-minute Blue Amberol records ; with these machines the user needed to adjust a knob or lever ( which changed gearing ) and change the reproducer ( which held different sizes of styli ) when going from one type of record to another.