Dynaflex (1971 – late 1970s)

Dynaflex was a type of 12-inch vinyl LP produced by RCA, and introduced in early 1971. It is essentially a very thin LP that was able to flex more without damage, and also claimed to produce a smoother and quieter playing surface.

When introduced, Dynaflex records had a thickness of just 0.03 inches, and a weight of 90 grams (standard LPs were usually around 135 grams).

Their thinness could cause problems with automatic record changers (two discs might drop instead of one for instance) and they needed to be played on a full-size turntable platter otherwise the unsupported section of the record might droop under the weight of the stylus.

There is debate about whether Dynaflex records sound better or worse than standard vinyl, but whatever the truth, RCA stopped using the Dynaflex name sometime in the late 1970s and returned to standard weight vinyl records.

Sources / Resources

Akai ¼-inch open reel video tape (1969 – late 1970s)

Akai ¼-inch video tape was an analogue open reel video tape format introduced in 1969. It used helical-scanning and initially only recorded in black and white (a colour video recorder using the tape, the Akai VTS-150, was introduced in 1974).

The first machine to use the format was the Akai VTS-100, a portable video tape recorder with a detachable video monitor and a video camera. An optional RF modulator was available for playback through a standard television set.

Video resolution was 200 lines, and the system was aimed at the consumer market. One advantage over other domestic video tape recorders that used ½-inch wide tape (such as the EIAJ-1 ½-inch format) was that tape for the Akai system was much cheaper. A number of different companies produced tape for the Akai format.

Most of the tape was on plastic 5-inch reels with cine spindle hubs but the VT-700, a stationary video tape recorder introduced by Akai in the early 1970s, could accommodate 10.5-inch NAB hub reels of ¼-inch video tape as well.

Tapes recorded on the later colour VTS-150 are not compatible with tapes recorded on black and white models due to differences in tape speed.

Sources / Resources

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.

Sources / Resources

EV Stereo-4 (1970 – 1975)

The EV Stereo-4 system (also known as EV-4) was a matrix quadraphonic format, developed by Leonard Feldman and Jon Fixler in 1970 and taken up by Electro-Voice as the first commercial quadraphonic system for vinyl records.

A handful of record labels used the system, including Ovation, Project 3 and Quad-Spectrum, and RadioShack sold compatible decoders and systems in the US.

EV Stereo-4 emphasises front (left to right) and front-to-rear separation, but there is less separation between the two rear channels.

In 1973 Electro-Voice introduced a decoder that could also play SQ and QS quadraphonic records with good results, but despite this Stereo-4 was pushed out of the market by these other systems and nothing appears to have been released on EV Stereo-4 after 1975.

Sources / Resources

Philips EL 3583 (1963 – early 1970s)

The Philips EL 3583 was an office dictation machine that used small cartridges of ⅛-inch tape. It appears to have been introduced around 1963, around the same time that Philips also introduced their Compact Cassette system, and it may have replaced the EL 3581 system.

The threading mechanism was unusual; a supply cartridge and a separate take-up cartridge would be placed in the machine and lever would be depressed causing a latch at the end of the supply cartridge’s tape to be pulled across and to lock into the take-up spool.

Like other dictation machines, the microphone also acted as a small speaker and contained a control to begin recording.

It’s unclear when the system was produced until, but it seems unlikely to be much beyond the early 1970s as Philips own Compact Cassette and mini-cassette designs, as well as other competing cassettes such as the Microcassette were available.

Sources / Resources

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.

Sources / Resources

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.

Sources / Resources

Philips Background Music Services cartridge (1970s – 1980s)

Philips Background Music Services cartridges were based on the Fidelipac B size cartridge and were 4-track mono cartridges for background music systems made by Philips. Being based on the Fidelipac cartridge meant they were endless loop tapes and would simply repeat the music once all four tracks had been played through.

There appear to have been two models of player, the BMS 2500 and the BMS 2600.

The cartridges themselves display a description of the type of music contained on them (for example, ‘music for stylish surroundings’) and are contained in a box that had the return address and space for a stamp on the rear, so the cartridges could be returned to Philips Background Music Services after use.

The system could be used for locations such as shops, offices and restaurants, and the pre-recorded music was licensed for public performance

By 1989 Philips had begun using the CD-BGM format, for example in its BMS 3000 player.

Sources  / Resources

Little LP (1961 – 1975)

The Little LP (also known as a Jukebox EP) was a 7-inch vinyl record with up to three songs on each side, that played at 33 ⅓ rpm in stereo, and had a small centre hole. They were first introduced by Cadence Records in late 1961, though the Cadence version was in mono and was not designed for jukeboxes.

The Little LP was not successful in the retail market, but it was picked up by Seeburg for use in their new jukebox, introduced in September 1962. The Seeburg version of the Little LP was in stereo, came with title strips, and had a colour cover for display in the jukebox. A number of record companies signed up, mostly easy listening and classical labels, and by 1963 there were 233 titles available with over 1,000 by 1966. Little LPs were also made for other jukebox manufacturers such as Wurlitzer and ATI.

Little LPs were essentially cut-down versions of the full 12-inch LP, and shared the same artwork. Record companies saw the potential of promoting the full LP version by having a selection of tracks available to hear, and the cover on display, in places where adult listeners gathered.

However by 1969, output of Little LPs had dropped sharply. A couple of small manufacturers revived the format in the early 1970s, but only a few titles per year were released in the period 1970-1975. Seeburg introduced new jukeboxes that didn’t play Little LPs in 1971, and the introduction of quadraphonic Little LPs didn’t make any difference as there were very few quadraphonic jukeboxes to play them on.

There were no new titles on the Little LP format for jukeboxes in 1976, but a few Little LPs have been released for the retail market as specialty items since then.

Sources / Resources

Polaroid Polavision (1977 – 1979)

Polavision was a home movie film system launched by Polaroid in 1977. What set it apart from other home movie formats like Super 8 was that Polavision offered quick developing at home in just a few minutes.

The film was contained in a cartridge for easy loading in the handheld camera, and this had two reels for the film as well as a small lens and prism for projection as the film remained in the cartridge when projected. Unfortunately, the cartridge only held enough film for around two and a half minutes of recording.

The film was in colour (using the additive process), but there was no sound, and the images were criticised for being murky. The film was not very sensitive, and required a lot of light to film successfully.

Developing and projecting the film required the Polavision tabletop projector that projected the images onto a translucent screen. Developed film however can be extracted from the cartridge for use on a Super 8 projector.

The Polavision system was a commercial failure and lost Polaroid a considerable amount of money. As well as having to compete with Super 8, Betamax and VHS home video cameras were becoming available (though at this stage still very expensive and requiring a separate portable recorder).

It was withdrawn in 1979.

Sources / Resources