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[h=3]Linear tracking[/h]
Technics SL-Q6 linear tracking turntable.
If the arm is not pivoted, but instead carries the stylus along a radius of the disc, there is no skating force and little to no cartridge angle error. Such arms are known as linear tracking or tangential arms. These are driven along a track by various means, from strings and pulleys, to worm gears or electromagnets. The cartridge's position is usually regulated by an electronic servomechanism or mechanical interface, moving the stylus properly over the groove as the record plays, or for song selection.
Early developments in linear turntables were from Rek-O-Kut (portable lathe/phonograph) and Ortho-Sonic in the 1950s, and Acoustical in the early '60s. These were eclipsed by more successful implementations of the concept from the late 1960s through the early '80s.[SUP][43][/SUP] Of note are Rabco's SL-8, followed by Bang & Olufsen with its Beogram 4000 model in 1972. These models positioned the track outside the platter's edge, as did turntables by Harman Kardon, Mitsubishi, Pioneer, Yamaha, Sony, etc. A '70s design from Revox harkened back to the '50s attempts (and, record lathes), positioning the track directly over the record. An enclosed bridge-like assembly is swung into place from the platter's right edge to its middle. Once in place, a short tonearm under this "bridge" plays the record, driven across laterally by a motor. The Sony PS-F5/F9 (1983) uses a similar, miniaturized design, and can operate in a vertical or horizontal orientation. The Technics SL-10, introduced in 1981, was the first direct drive linear tracking turntable, and placed the track and arm on the underside of the rear-hinged dust cover, to fold down over the record, similar to the SL-Q6 pictured.
The earliest Edison phonographs used horizontal, spring-powered drives to carry the stylus across the recording at a pre-determined rate. But, historically as a whole, the linear tracking systems never gained wide acceptance, due largely to their complexity and associated production/development costs. The resources it takes to produce one incredible linear turntable could produce several excellent ones. Some of the most sophisticated and expensive tonearms and turntable units ever made are linear trackers, from companies such as Rockport and Clearaudio. In theory, it seems nearly ideal; a stylus replicating the motion of the recording lathe used to cut the "master" record could result in minimal wear and maximum sound reproduction. In practice, in vinyl's heyday it was generally too much too late.
Since the early 1980s, an elegant solution has been the near-frictionless air bearing linear arm which requires no tracking drive mechanism other than the record groove itself. This provides a similar benefit as the electronic linear tonearm without the complexity and necessity of servo-motor correction for tracking error. In this case the trade-off is the introduction of pneumatics in the form of audible pumps and tubing. A more elegant solution is the mechanically-driven low-friction design also driven by the groove. Examples include Souther Engineering (U.S.A.), Clearaudio (Germany), and Aura (Czech Republic). This design places an exceeding demand upon precision engineering due to the lack of pneumatics.
So there is a mechanical means of tracking IE gears, string? That makes it more prone to errors as parts wear?
Technics SL-Q6 linear tracking turntable.
If the arm is not pivoted, but instead carries the stylus along a radius of the disc, there is no skating force and little to no cartridge angle error. Such arms are known as linear tracking or tangential arms. These are driven along a track by various means, from strings and pulleys, to worm gears or electromagnets. The cartridge's position is usually regulated by an electronic servomechanism or mechanical interface, moving the stylus properly over the groove as the record plays, or for song selection.
Early developments in linear turntables were from Rek-O-Kut (portable lathe/phonograph) and Ortho-Sonic in the 1950s, and Acoustical in the early '60s. These were eclipsed by more successful implementations of the concept from the late 1960s through the early '80s.[SUP][43][/SUP] Of note are Rabco's SL-8, followed by Bang & Olufsen with its Beogram 4000 model in 1972. These models positioned the track outside the platter's edge, as did turntables by Harman Kardon, Mitsubishi, Pioneer, Yamaha, Sony, etc. A '70s design from Revox harkened back to the '50s attempts (and, record lathes), positioning the track directly over the record. An enclosed bridge-like assembly is swung into place from the platter's right edge to its middle. Once in place, a short tonearm under this "bridge" plays the record, driven across laterally by a motor. The Sony PS-F5/F9 (1983) uses a similar, miniaturized design, and can operate in a vertical or horizontal orientation. The Technics SL-10, introduced in 1981, was the first direct drive linear tracking turntable, and placed the track and arm on the underside of the rear-hinged dust cover, to fold down over the record, similar to the SL-Q6 pictured.
The earliest Edison phonographs used horizontal, spring-powered drives to carry the stylus across the recording at a pre-determined rate. But, historically as a whole, the linear tracking systems never gained wide acceptance, due largely to their complexity and associated production/development costs. The resources it takes to produce one incredible linear turntable could produce several excellent ones. Some of the most sophisticated and expensive tonearms and turntable units ever made are linear trackers, from companies such as Rockport and Clearaudio. In theory, it seems nearly ideal; a stylus replicating the motion of the recording lathe used to cut the "master" record could result in minimal wear and maximum sound reproduction. In practice, in vinyl's heyday it was generally too much too late.
Since the early 1980s, an elegant solution has been the near-frictionless air bearing linear arm which requires no tracking drive mechanism other than the record groove itself. This provides a similar benefit as the electronic linear tonearm without the complexity and necessity of servo-motor correction for tracking error. In this case the trade-off is the introduction of pneumatics in the form of audible pumps and tubing. A more elegant solution is the mechanically-driven low-friction design also driven by the groove. Examples include Souther Engineering (U.S.A.), Clearaudio (Germany), and Aura (Czech Republic). This design places an exceeding demand upon precision engineering due to the lack of pneumatics.
So there is a mechanical means of tracking IE gears, string? That makes it more prone to errors as parts wear?
