User:Mjb/Discogs notes

Formats

The formats list is incomplete and has errors and misleading guidance such as "Only to be used for production runs, not for one offs" when in fact we do allow one-offs which don't meet a vague definition of "homemade".

I tried starting a discussion re: updating the definitions of Acetate and Lathe Cut, but nobody replied.

Here are my current suggestions for some replacement entries, although I admit these may contain too much detail:

Acetate (new definition)

An acetate, also known as a lacquer cut or dubplate, is similar to a vinyl record, but the disc is made of lacquer-coated metal. An acetate can be played directly about 6 times before the audio quality becomes intolerable. The lacquer also shrinks and flakes off over time, rendering many older acetates unplayable. Most acetates are not played, but rather are electroplated and used as the basis for physical molds for pressing vinyl records. This type of acetate often has an inch or more of unused space near the outer edge.

In the mid-20th Century, there were coin-operated novelty booths which created small, one-off acetates of audio recorded by the buyer through a microphone; these should not be submitted. Historically significant one-offs may be submitted, as well as professional test cuts that were made for releases already in the database, but any other acetates should be discussed first.

Lathe Cut (new definition)

A lathe cut is similar to an acetate, but instead of being cut into an oversized lacquer-coated metal disc, the groove is carved directly into some other material. The material can be vinyl, but this is not how vinyl records are normally made; sound quality is very poor as compared to pressed vinyl. Lathe cuts tend to be novelty items and generally should not be submitted. In the 2010s, a number of vendors on online auction sites began selling bootleg picture discs which are advertised as rare collectors' items, but which in reality are homemade lathe cuts which may not even contain the pictured artist's music. Historically significant lathe cuts, even one-offs, may be submitted, but others should be discussed first.

Pathé Disc (new definition)

A Pathé Disc is similar to a shellac 78, but contains a vertically cut groove, like an Edison Disc (only the depth of the groove changes). Pathé Discs were on the Pathé label and often came in unusual sizes. Early discs were 90 RPM with an inside-start groove. In 1915 they switched to 80 RPM and outside-start. Pathé Discs were produced from 1905 to 1932, mostly on the Pathé label.

In 1920, the company also began producing lateral-cut records with the Actuelle or Pathé Actuelle label; these are mostly 10" records and should be entered as Shellac, not Pathé Disc.

More info:

• http://www.obsoletemedia.org/pathe-vertical-cut-record/
• https://www.discogs.com/label/835148-Path%C3%A9-Phonograph-Radio-Corp

Edison Disc (new definition)

An Edison Disc, also known as a Diamond Disc, is similar to a shellac 78, but it is ¼-inch thick, and contains a vertically cut groove, like a Pathé Disc (only the depth of the groove changes). Edison Discs were produced from 1912 to 1929.

More info: http://www.obsoletemedia.org/edison-diamond-disc/

Shellac (new definition)

Shellac records account for the majority of what are called "78s". They are made partially from secretions of the lac beetle. Speeds varied greatly at first, but since the mid-1920s, most play at exactly 78.26 RPM (commonly regarded as "78 RPM"). Most are 10" or 12" in diameter, and they are pressed from molds which are based on original wax discs cut during a live performance via a lathe with a horn or microphone attached. The groove is laterally cut. Most shellac records contain a type of groove called "coarse" or "standard play", meaning it is made for a needle or conical stylus with a tip roughly 3 mil (0.0030") in diameter, as compared to the post-WWII "fine" or "microgroove" type of groove which was standard for vinyl LPs and 45s.

Most "shellac" records were actually a composite of materials around a core of some kind, with the amount of shellac and the types of fillers variable and secret. New shellac records were shiny and resembled black vinyl, but repeated plays and mishandling often dulls the finish significantly. Shellac records were produced from 1889 to about 1960.

Not all 78 RPM records are shellac; post-WWII releases can be Shellac or Vinyl. After WWII, some companies switched to hard, thin plastic formulations, often labeled "unbreakable"; these should be considered Vinyl. If the record is thick and coarse-groove, either Shellac or Vinyl is acceptable. A relatively small number of vinyl records were produced with coarse groove and 33 RPM, or microgroove and 78 RPM. These should be entered as Vinyl, not Shellac.

Do not use the Mono tag on Shellac records; they are all mono.

Vinyl (new definition)

Vinyl is the most popular record format. It is normally pressed from hot, high-pressure molds in 7", 10" or 12" sizes, with the groove laterally cut at 33⅓ or 45 RPM, or less commonly at 78.26 ("78") or 16⅔ RPM. Vinyl is not a single material, but rather a chemical mix consisting mainly of a type of petroleum-based plastic called Polyvinyl Chloride (PVC), dyes for color (typically black), an antifungal agent, and plasticizers which add flexibility. Vinyl records are lightweight and thin, as compared to shellac 78s, and many are somewhat flexible, unless marketed as "unbreakable".

78 RPM vinyl records for consumers debuted in late 1945. The 33⅓ RPM microgroove "LP" (10" or 12") debuted in 1948. The 7" 45 RPM format debuted in 1949 and was also microgroove. Variations exist, such as 7" at 33⅓ RPM or 12" at 45 RPM. Coarse-groove vinyl records also exist but were uncommon and were discontinued by the late 1950s.

Microgroove records are designed for a stylus with a tip of 0.7 to 1.0 mil (0.0007" to 0.0010") at a relatively low tracking force (5 grams or less, usually around half that). The groove can potentially be so narrow, shallow, and tightly packed that a coarse-groove stylus cannot stay play it at all. However, many mono microgroove records do not push those limits and can actually be played with such a stylus; it just rides higher in the groove.

Vinyl records were all mono until stereo was introduced in 1957. Stereo is always microgroove, with the side channel stored in the groove depth. Many stereo records were initially marketed as "compatible", to reassure consumers that the new format was compatible with mono systems.

A "picture disc" is clear vinyl with a visible, printed cardstock core.

Not all 7" 45s are vinyl; some are Styrene, a separate format. [We need info here on how to distinguish.]

Not all vinyl records are pressed from molds; some novelty records are directly cut using blank vinyl discs and a lathe, and have very poor sound quality; see the Lathe Cut format.

The plural of vinyl is vinyl. If you have many vinyl records, you have a lot of vinyl, not "vinyls".

More info:

• http://www.obsoletemedia.org/lp/
• http://www.obsoletemedia.org/7-inch-single/