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.
An encrypted USB flash drive is a USB flash drive featuring hardware encryption, and first seems to have appeared in 2004.
There are usually two separate partitions on the drive; one is a read-only partition that contains the encryption software, the other is the secure encrypted partition that is only accessible once the correct password is entered. Most drives use Advanced Encryption Standard (AES) encryption. The drives may have a feature whereby if an incorrect password is entered too many times, the secure partition becomes inaccessible and will need to be reformatted.
As the encryption software is run from the drive itself, nothing needs to be installed on the computer which makes it easier to use than having to install the necessary software on each computer that the drive will be used on, but makes the drive vulnerable if the software no longer runs in newer operating systems.
Gold CD-Rs (sometimes called archival CD-Rs) are intended to have a much longer life than standard CD-Rs. The main difference is that these CD-Rs use gold as the reflective layer to prevent oxidation (also known as laser rot), and they generally also use higher-quality dyes (preferably phthalocyanine). Being write-once also means the data cannot be accidentally overwritten.
Gold CD-Rs were introduced by MAM-A (Mitsui Advanced Media – America) around 1996.
Some gold CD-Rs suggest that they can offer data storage for to 300 years. Unfortunately there is no way to tell if this will be the case, and the future obsolescence of optical drives means they still should not be relied upon for long-term data storage.
The DTS 5.1 Music Disc was a Compact Disc format offering surround sound audio, usually in the 5.1 configuration. The discs would play in a standard Compact Disc player, but without the use of a DTS decoder all that would be heard is white noise. The potential confusion between DTS 5.1 Music Discs and standard Compact Discs meant some retailers were reluctant to stock them. There is some compression applied to the audio, so sound quality is arguably slightly lower than a standard CD.
Formats such as DVD-Audio and Super Audio CD, launched a few years later, could also offer surround sound and meant an end to the DTS 5.1 Music Disc, though several hundred titles were released on the format.
DTS surround sound technology is also used in movie theatres, on DVD-Video and on Blu-ray. It was also used on a small number of LaserDiscs.
QSound is an audio processing system introduced by QSound Labs. It was applied at the sound mixing stage and attempts to produce a surround sound effect from a stereophonic source. It was used on around 65 Compact Disc albums from 1991 to around 2001, which display the QSound logo. The first album to use QSound was Madonna’s ‘The Immaculate Collection’ and all the tracks were either re-mixed or mixed using the system.
No additional equipment was necessary to play a QSound Compact Disc, and the discs comply fully with Red Book standards.
As well as Compact Disc albums, the QSound technology was also applied to computer game audio, television programmes and film soundtracks.
On mono devices, music mixed using the QSound system can have elements missing.
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.
Launched in 2004, The Fujifilm PhotoDisc CD-R is essentially a standard CD-R disc with a black substrate layer that claims to protect the data from ultra-violet and solar radiation. It also uses a different dye (phthalocyanine rather than the usual cyanine) in the recording layer, which should offer more resistance to heat and sunlight.
Although they are reported to be very reliable, for archival purposes gold archival CD-R discs are probably better.
Despite the name, the discs can be used for any purpose that a standard CD-R can be used for, and don’t just store photos.
The Blu-spec CD was introduced in 2008 by Sony, and is a Red Book-compliant audio Compact Disc, so is playable on all audio Compact Disc players. Sony launched with 60 titles on Blu-spec CD.
Its name is derived from the shorter-wavelength blue laser used to create the master copy, which is claimed to produced more precise pits to reduce distortion due to reading errors, along with a new polymer polycarbonate developed for the Blu-ray Disc.
In 2012, a newer version called Blu-spec CD2 (or BSCD2) was introduced that claimed to have a more precise cutting machine and master discs made from silicon wafers. Sony called it Phase Transition Mastering.
Due to existing limitations of Compact Disc Digital Audio, it is debatable whether Blu-spec CDs offer better sound quality as there is no extra information stored on the disc.
As of 2017, new titles are still being released on both formats.
S-VHS-C (Super VHS Compact) was the compact version of S-VHS tape for use in analogue consumer camcorders.
It was introduced by JVC in 1987, and offered a horizontal resolution of about 400 lines over VHS-C‘s 240 lines, on tapes that could hold 30 or 45 minutes at standard speed.
The tapes could be placed in an adaptor and played back in an S-VHS deck, but it needed to be an S-VHS adaptor as the adaptor for VHS-C cassettes was differently notched to identify the tape as S-VHS. S-VHS-C tapes cannot be played back in a normal VHS machine even with an adaptor.
S-VHS-C competed with Hi8, which offered a comparable level of quality, but few S-VHS-C camcorder models were available.
No digital version was introduced (unlike full-size VHS with its D-VHS variant, and Hi8 with Digital8) and it was made obsolete by smaller digital formats like MiniDV, and eventually hard-drive recorders.