Did Edison license blue amberol technology to Columbia?
Posted: Fri Nov 20, 2015 1:57 pm
I recently obtained a Dictaphone Practice Record. It's a cylinder, shaped like normal Ediphone and Dictaphone cylinders, same diameter as entertainment cylinders but with a thicker wall and longer.
It's pre-recorded, and consists of a stentorian dude elocuting dictated letters for some hapless typist to transcribe. I like this kind of stuff because the content often reflects the times in unintentionally interesting ways.
The thread pitch on business phonographs is different than that of the entertainment cylinders, but I am lucky enough to own a cool old spring wound Edison Business Phonograph, so that part is handled.
But here's the weirdness. The dictaphone practice cylinder is not wax, and although it does play without skipping, it is very quiet, and has bleedthrough under the main content, seemingly from adjacent grooves. Closer examination reveals that the cylinder seems highly similar in composition to the Edison Blue Amberol, except black in color. I'm not with it now so can't say whether there is a plaster core, but I don't think there is.
My Business Phonograph is early and its reproducer is as well. Perhaps later on, all Ediphone and Dictaphone systems went to a tighter or thinner groove and so my stylus is just too fat. I thought to put a Model H reproducer on it to test that theory, but it isn't compatible to the carriage configuration.
I have some newer ediphones out in the garage someplace and will be able to borrow a newer reproducer to test that theory eventually. But in the meantime, does anyone know the answers to these two questions:
1. did business cylinder grooves and stylii get narrower at some point?
2. how was Columbia able create an amberol-like cylinder?
It's pre-recorded, and consists of a stentorian dude elocuting dictated letters for some hapless typist to transcribe. I like this kind of stuff because the content often reflects the times in unintentionally interesting ways.
The thread pitch on business phonographs is different than that of the entertainment cylinders, but I am lucky enough to own a cool old spring wound Edison Business Phonograph, so that part is handled.
But here's the weirdness. The dictaphone practice cylinder is not wax, and although it does play without skipping, it is very quiet, and has bleedthrough under the main content, seemingly from adjacent grooves. Closer examination reveals that the cylinder seems highly similar in composition to the Edison Blue Amberol, except black in color. I'm not with it now so can't say whether there is a plaster core, but I don't think there is.
My Business Phonograph is early and its reproducer is as well. Perhaps later on, all Ediphone and Dictaphone systems went to a tighter or thinner groove and so my stylus is just too fat. I thought to put a Model H reproducer on it to test that theory, but it isn't compatible to the carriage configuration.
I have some newer ediphones out in the garage someplace and will be able to borrow a newer reproducer to test that theory eventually. But in the meantime, does anyone know the answers to these two questions:
1. did business cylinder grooves and stylii get narrower at some point?
2. how was Columbia able create an amberol-like cylinder?