Brief History of the Diamond Disc

Origin & Originality

The Edison Disc also known as a Diamond Disc record, was a type of audio disc record marketed by Edison Records from 1912 to 1929. As early as 1910, there had been experiments in the Edison laboratory directed at the production of a flat disc record. It was put on the market in 1913, as the Diamond Disc, to be played with a diamond stylus in the new Diamond Disc Phonograph.
Diamond Discs were created as a response to competition Edison had previously concentrated on producing phonograph cylinders, but decided to get into the disc market due to the increasing market share of disc sound recordings, especially the discs of companies such as Victor Talking Machine Company (what would later be called "78 records"). Victor and most other disc record companies used side to side or lateral motion of the stylus in the record groove, whereas in the Edison system the movement was up and down or vertical, as in a cylinder record. The grooves on an Edison Disc are smooth on the sides and have a variable depth.

Strengthes & Weaknesses

Diamond Discs arguably had better audio fidelity, but were more expensive than and incompatible with other brands of records, and ultimately lost out in the marketplace. The machine had a heavier reproducer than the one used on cylinders, so a hard surface disc was needed; this was achieved with a plastic named Condensite. The records weighed one pound each, and measured a quarter-inch thick. There were 150 turns (grooves) per inch. At 80 rpm, the I2-inch Diamond Disc played 7 Ih minutes, and the 10-inch record played five minutes. There was no warping, and no perceptible wearing of the surface, even after hundreds of plays. Outstanding audio fidelity for its time brought the Diamond Disc great acclaim; it was the medium of the remarkable tone tests that Edison used to demonstrate the quality of his product. Considering the longer playing time of the Diamond Discs, their price was competitive with standard discs: $1 for 1O-inch records, while standard records were sell- ing for .60ยข. What prevented the Diamond Disc from gaining a greater market share was its excessive surface noise (gradually improved, but a reasonably quiet surface did not emerge until 1924), and the tendency of the earlier discs to separate their layers and to curl or crack.

The Death of Diamond Discs

In late 1927 Diamond Discs were being electronically recorded. Edson did pioneer in the manufacture of long-playing records, from 1926, but those were not well received. Just before Edison dropped out of the record business, he offered a lateral-cut electrically recorded disc (summer 1929), but it was without outstanding qualities. The final Diamond Disc was cut on September 18, 1929.

 

Here is an index of all 27,000 Published and Unpublished Edison Diamond Discs ever produced (Microsoft Excel)

 

Courtesy of The Encyclopedia of Recorded Sound and

"Edison Diamond Disc Records (Hill and Dale) Manufacturing Processes as of 1920 to 1929 from"Edison Diamond Disc Records (Hill and Dale) Manufacturing Processes as of 1920 to 1929 from Wax Masters to Condensite Records" by Paul B. Kasakove.