Edison Long Playing Record

Imprint used by Edison Records for their Long-Playing, Vertical-Cut ("Diamond") Discs.
Active only between 1926-27.

Discs of that kind were notable, for being the world's first ever LPs, to be produced and sold (predating 's LP format by 22 years).
The way it was achieved however was very different: instead of reducing the record's speed (as it was done by Columbia [[url=https://www.discogs.com/label/706461-Program-Transcription]and even by RCA Victor in the 1930's[/url]]), Edison decided to increase the record's TPI (threads-per-inch) from 150 to 450 (a strategy they previously used during the development of ).
Unfortunately, this resulted in these records requiring an unique Reproducer to play (all these records contained this disclaimer). To make the matters worse, the records' grooves were much thinner and therefore more prone to breaking, than the ones used on post-1948 LPs. In addition, the overall volume was about 40% lower, than on the regular "Diamond" Discs.

This format existed in two variations: "24 Minute" for 10-inch records and "40 Minute" for 12-inch ones (in fact, the latter ones were the only 12-inch "Diamond" Discs ever sold to the public).