Editing Edison Disc Record (section)

{{Short description|Type of phonograph record produced by Edison Inc. from 1912 to 1929}}
[[Image:EdisonRecordSleeveLivingArtist.jpg|thumb|right|250px|Edison Records logo from 1910s sleeve]]
The '''Edison Diamond Disc Record''' is a type of [[phonograph record]] marketed by [[Thomas A. Edison, Inc.]] on their [[Edison Record]] label from 1912 to 1929. They were named Diamond Discs because the matching Edison Disc Phonograph was fitted with a permanent conical diamond stylus for playing them. Diamond Discs were incompatible with lateral-groove disc record players, e.g. the Victor Victrola, the disposable steel needles of which would damage them while extracting hardly any sound. Uniquely, they are just under {{frac|1|4}}&nbsp;in ({{cvt|0.235|in|mm|disp=semicolon|order=flip}}) thick.<ref name="Gracyk1">{{cite web|url=http://www.gracyk.com/diamonddisc.shtml|title=Tim Gracyk's Phonographs, Singers, and Old Records – Edison Diamond Discs: 1912–1929|publisher=Gracyk.com|access-date=18 September 2014|archive-date=20 November 2006|archive-url=https://web.archive.org/web/20061120114423/http://www.gracyk.com/diamonddisc.shtml|url-status=dead}}</ref>

[[File:Stack of 80 RPM Edison Disc Gramophone Records.jpg|thumb|right|200px|Early Diamond Disc records, showing the thickness of each record and number stamped into side.]]
Edison had previously made only [[phonograph cylinders]] but decided to add a disc format to the product line because of the increasingly dominant market share of the [[shellac]] disc records (later called 78s because of their typical rotational speed in revolutions per minute) made by competitors such as the [[Victor Talking Machine Company]]. Victor and most other makers recorded and played sound by a lateral or side-to-side motion of the [[stylus]] in the record groove, while in the Edison system the motion was vertical or up-and-down, known as [[Vertical cut recording|vertical recording]], as used for cylinder records. An Edison Disc Phonograph is distinguished by the [[diaphragm (acoustics)|diaphragm]] of the reproducer being parallel to the surface of the record. The diaphragm of a reproducer used for playing lateral records is at a right angle to the surface.

In the late summer and early fall of 1929 Edison also briefly produced a high-quality series of thin electrically recorded lateral-cut "Needle Type" disc records for use on standard record players.