Centre-start phonograph record (1905 – )

Centre-start (or inside-start) phonograph records date back as far as 1905 with the Pathé vertical-cut disc record, that in addition to other unusual features such as being vertically rather than laterally cut and running at 90rpm, required the stylus to be placed in the area that on other records would be the run-out grooves. In 1915, Pathé switch to a more conventional outside-start.

Later, Electrical transcription discs (1920s – 1980s) often used centre-starts, sometimes on both sides and sometimes alternating with an outside-start on the second side, possibly to reduce changes in sound quality between the end of one side and the start of the other. As the stylus moves to the centre of a record, the linear groove speed decreases and there can be more ‘end-groove distortion’.

Since then, centre-start records have tended to be uncommon, and were usually used as a novelty or promotional feature. A couple of examples include King Kurt’s Destination Zululand 12-inch single (1983) and more recently Jack White’s Lazaretto 12-inch LP (2014), which had a centre-start on side one.

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Soundmirror (1948 – 1954)

Soundmirror tape (also known as ‘magic ribbon tape’) was a magnetic tape format for use on the Soundmirror tape recorder made by Thermionic Products in the United Kingdom. What was unusual about it was that was made of paper with an oxide coating rather than the standard plastic tape.

Thermionic introduced the Soundmirror tape recorder in late-1948 under licence from the Brush Development Company in the US, after introducing the Recordon dictation disc (also made of paper) earlier in the year. The Soundmirror machine became the first domestic tape recorder on the UK market.

While the Recordon disc was aimed at the dictation market, the Soundmirror format was aimed at longer duration recording such as concerts, meetings and lectures. The tape ran at 7.5 inches per second on a maximum reel size of 7-inches, so allowing up to around 30 minutes of recording.

Production of the Soundmirror continued until 1954 by which time acetate (and later polyester) had become the standard magnetic tape base material.

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Recordon (1948 – mid 1950s)

The Recordon was an office dictation system using 9-inch paper disc with a magnetic coating. It was introduced by the UK company Thermionic Products in 1948 with the Recordon TP503 machine, made under license by the Brush Development Company of the USA that produced the Mail-A-Voice system.

The Recordon Recording Disc had fold lines printed on it, and could be folded for mailing. The system was fairly low fidelity, but was adequate for dictation purposes and as the recording runs from the centre to the outside of the disc, quality improves. Discs could be erased for re-use.

A couple of further models of the Recordon were produced, but in the mid-1950s Thermionic switched to the Agavox system.

Thermionic also introduced the Soundmirror tape recorder to the UK market in 1948, and like the Recordon this also used paper as the base material, in this case for magnetic tape.

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Mohawk Midgetape (1955 – early 1960s)

The Mohawk Midgetape was an early portable tape recorder introduced by Mohawk Business Machines in 1955 with the Midgetape 44 model.

It used a tape cassette in a metal casing with ¼-inch tape allowing 30 or 45 minutes of recording on each side of the tape. The cassette design is unusual in having the spools on top of each other (coaxial).

The is no fast forward, and rewinding is done with a fold-out handle. It came with a microphone, and had a headphone jack. Accessories included a separate amplifier, an adaptor for recording telephone conversations, a wristwatch microphone, and a leather bag with hidden microphone.

Later models were fully transistorised (the 44 had used subminiature valve tubes) and the final Midgetape model was the 500 Professional introduced in 1959. There was a also a machine based on the Midgetape called the Lafayette Transcoder that in 1961 claimed to be able to record conversation up to 30 feet away.

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16⅔ rpm LP (Long Play) 12 inch record (early 1950 – early 1970s)

Whilst the vast majority of Long Play records were played at 33⅓ rpm, a few records were made to be played at half that speed, 16⅔ rpm (usually listed as 16 rpm). Many of these were spoken word, since the slow speed meant lower fidelity reproduction, but despite this there were a few music releases, mainly from South Africa.

Even though 16 rpm records were rare even at the time, many record decks of the 1950s, 1960s and even into the 1970s came with a 16 rpm speed setting.

The 16⅔ rpm speed was also used for the short-lived in-car Highway Hi-Fi system of 1956 using 7-inch discs, and for the Seeburg Background Music System of 1959 using 9-inch disks.

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Stereophonic LP (Long Play) 12 inch record (1957 – )

The current system for creating stereophonic (2 channel) phonograph discs date back to 1933 when Alan Blumlein, a senior sound engineer at EMI in London, demonstrated a single-groove system in which the stylus moves both horizontally and vertically.

When the 12-inch Long Play record was launched in 1948, it was initially monophonic, and it wasn’t until 1957 that stereophonic LPs were released, by now using a refined version of the EMI system developed by Westrex (a division of Western Electric) called Westrex 45/45 in which each channel drives the cutting head at a 45 degree angle to the vertical.

In late 1957, Audio Fidelity Records and Bel Canto in the US released demonstration stereo LPs, with the the Bel Canto release on multicoloured vinyl. The first mass-produced stereophonic LPs were released in early 1958.

Mono LPs continued to be released alongside stereo LPs for the next ten years or so with major labels ceasing production in 1968, but 7-inch singles continued to be mono for longer, into the 1970s in some cases.

Stereo records produced using the Westrex system played well on a mono record player, and mono records could be played on a stereo system.

In the 1970s, quadraphonic (4 channel) LPs were produced, but were not a great success partly because there were several competing and incompatible systems.

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Open reel instrumentation and data logging tape (1949 – 2000s)

Magnetic tape was first used for data logging and instrumentation recording in 1949, when Jack Mullins installed modified Ampex Model 300s at Point Mugu Naval Air Station and at Edwards Air Force Base, both in southern California.

Tape has been heavily used since then for military, industrial, government and research applications. The Inter-Range Instrumentation Group (IRIG) set the standards for instrumentation tape recorders.

Instrumentation recorders were built to much more stringent standards than other tape recorders, and recorders that used direct, FM and PCM recording have been available.

On ¼-inch wide tape, there are typically 4 tracks, whereas on ½-inch tape there were 7, or sometimes even 14, tracks. On 1-inch tape, there were 14 or 28 tracks. Tape is usually wound on the reel with the recording surface facing towards the hub (the opposite of audio tape). Metal NAB reels were often used, for reels between 10.5 and 16-inches, but 7-inch plastic reels with cine spindle hubs have also been used.

Instrumentation recorders also used tape in cassette form, including systems that recorded onto S-VHS tape, and the Digital Instrumentation Recorder from Sony that used the SD1 cassette.

Instrumentation and data logging systems now use hard disks or flash memory for storage.

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White label vinyl record (1948 – )

White label vinyl records are generally 12-inch LPs, or 7-inch singles and come with a plain centre label (usually white) and are in plain packaging. The centre label might have handwritten details of the artist and title, or may be rubber stamped, or have a sticker applied.

Some white label records are test pressings made by the pressing plant, usually in quantities of 5 or less,  and then listened to to check the sound quality before pressing larger runs.

Some white label records are produced for promotional purposes, including advance copies sent to retailers or to DJs. Sometimes white labels are used to conceal artist identities, so the record is listened to without prejudice. Dance music producers might produce white label copies to play in dance clubs to gauge crowd response.

Other white label records are unofficial or partially unofficial releases, for example if a remix was made without the consent of the artist or label.

Generally, white label records are not distributed to the general public.

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Record album (late 1900s – 1950s)

Sometime during the late 1900s, record companies began to sell sets of 78rpm disc records in hardback ‘albums’. These were much like photograph albums, but with paper sleeves for multiple 10-inch or 12-inch phonograph discs, and they allowed record companies to sell complete musical works such as operas or classical works. The 78 rpm records of the time were only able to contain around 3 minutes of playing time on the 10-inch version, and 5 minutes on the 12-inch versions, so a longer complete work had to be spread across several discs.

Around the same time, empty record albums became available to allow listeners to store and protect their own discs, write information about the contents on an index page, and display the album on bookshelves.

Record albums eventually came to be used to contain compilations by artist, or by genre, in addition to longer works, and a set of 4-5 discs could contain 8-10 songs. Later releases had cover artwork and liner notes.

With the advent of the Long Play microgroove record in 1948 that could hold the same number of songs on a single disc there was no longer a need for record albums containing several discs, and indeed by the late 1950s the 78 rpm disc itself was being phased out. However, the term ‘album’ continues to be used to describe a collection of songs, whatever the format.

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Grundig Stenorette (1954 – 1970s)

The Stenorette was an office dictation machine introduced by Grundig in 1954, and successfully sold internationally. It was perhaps the earliest magnetic tape dictation system – at the time of its introduction, most office dictation systems were using discs or belts onto which grooves were pressed, such as the SoundScriber, Audograph, or Dictabelt systems. The first model, the Stenorette A, was nicknamed the ‘tree frog’ due to its green colour. Like some other dictation systems, the microphone doubled as the speaker, and contained stop/start controls.

The Stenorette cassette contained a single reel of ¼-inch tape, and a loop on the end was pulled out and clipped into the take-up reel. Recording time was 30 minutes per cassette, but some offered 45 minutes. Some tapes, particularly those from the US, seem to have no cover and are simply a small reel.

The Stenorette cassette system lasted into the 1970s with the introduction of the Stenorette SL model in 1972, but Grundig launched its first machine using its new cassette format, the Steno-Cassette in the same year. The Steno-Cassette was a true cassette containing dual reels and as well as being more compact, didn’t need to be rewound before being removed from the machine. The Stenorette name was continued on machines using the newer Steno-Cassette format.

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