Thanks daveyf and zavato. My answer to the original question in this thread is, "yes, the LP12 is still in use" despite its 'old design' and the LP12 serves as a "reference." lharasim suggested that current vogue favors idler wheel and direct drive turntables over belt driven designs like the LP12.
For what it is worth, Thorens introduced a direct drive turntable in 1929. (See "Turntable, Brinkmann Oasis - a white paper" published by Brinkmann Audio Gmbh.) The idler wheel design is quite old, too, but I am uncertain of its first implementation. Suffice it to say that both of these "in vogue" drive designs are not new but rather are enjoying renewed popularity as some people have highly refined the implementations of each. VPI and Brinkmann manufacture fantastic direct drive turntables that significantly advance the state of the art that Technics established in the late 60's for its direct drive tables. Likewise, Chris Thornton and Chris Harban make gorgeous plinths into which restored Thorens and Garrard idler wheel turntables may be installed with excellent results. Art Dudley has written extensively about how to build your own massive plinth to get the best out of a Thorens or Garrard idler wheel table, though Mr. Dudley's plinths do not appear to be so beautifully finished as the Thornton or Harban plinths.
So far as I know, the suspended subchassis belt drive design was the late bloomer here with Edgar Villchur introducing the AR-XA turntable in the early 1960's. Ivor Tiefenbrun introduced the LP12 in 1972 or 1973 using a design similar to the AR but much more refined and with much better sonic results.
Perhaps I did not say this so explicitly in my earlier post but want to say it more emphatically here: The underlying design of a turntable, whether belt, idler wheel or direct drive, whether suspended or suspensionless, matters less than the refinement and implementation of that design. All of these designs offer the possibility of excellent results if the implementations are well engineered and manufactured.
Until the LP12 came along, the common wisdom in audio dictated that turntables did not matter much. All they did was go round and round. Whether you liked the LP12 or not, Linn practically singlehandedly changed the audio industry in establishing the important role played by turntables.
Linn has refined its design for more than 40 years and the LP12 is a reference, a very high standard reference, by which other turntables may be judged. Many, many LP12's remain in use and, if reasonably cared for and properly set up, provide high quality playback.
Here is my personal experience, acknowledging that your mileage may vary: My circa 1989 LP12 has been upgraded to the mid-level Akurate build by using the Kore subchassis, Cirkus bearing and Lingo 3 power supply. (I use a Rega RB300 tonearm with a Koetsu Urushi Vermillion cartridge so the turntable is not all-Linn and may not satisfy Linn's requirements to be labeled as an "Akurate.") When compared to my far more expensive Spiral Groove SG1.1 with Triplanar VII uii and Koetsu Urushi Vermillion, the LP12 falls short in terms of bass extension and solidity, it is less quiet and less dynamic. The SG1.1 is more specific in its presentation: it plays more real, recognizable voices and instruments where the LP12 plays notes without the "real" quality that the SG1.1 imparts. The SG1.1 has a deeper and wider soundstage. That said, the LP12 is much less expensive than the SG1.1 and has been upgraded only to the middle level offered by Linn. The Rega RB300 cost less than 10% of what the Triplanar did and the turntable (without arm and cartridge) cost less than 20% of the SG1.1's MSRP. I believe that the RB300 fights well above its weight and can only be bettered if one spends much, much more money.
While the Linn seems to lose on almost every parameter I discuss, it does not lose by all that much. The LP12 sounds great as-is and suggests that a fully-upgraded LP12 might well surpass the SG1.1, though I would not make that judgment until hearing both in my system.
There is nothing new under the sun, at least as far as turntable design is concerned. The LP12 has been relentlessly refined and represents a reference-quality turntable. Depending upon the level to which an LP12 has been upgraded, and so long as it is competently set up, an LP12 can compare with the very best.
