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Linn LP12 History and Upgrade path

The following information was compiled from an official Linn customer services document.

The LP12 has had many upgrades through the years. The major ones were given exotic names, like Nirvana, Valhalla, Lingo, Trampolin reflecting the advances in accurate sound reproduction which they represented. There have also been many unnamed improvements like new feet, new baseboard, new armboard, new suspension springs and grommets and new plinth. The list is long and it means that an LP12 need never be out of date.

Cirkus Kit

The Cirkus upgrade to the LP12 focuses on bearing performance and the connection of the bearing housing to the sub-chassis. The improved bearing and stronger sub-chassis arrangement provides the turntable with greater stability and ensures the bearing sits perfectly true to the chassis of the turntable. This in turn minimises the risk of turntable platter movement with respect to the sub-chassis and arm. Even the slightest movement will introduce audible degradation to the reproduced signal.

Together the changes to the bearing and the sub-chassis make an enormous difference to the overall performance of the turntable. The specific changes are as follows :

  • The thickness of the bearing housing mounting flange has been substantially increased and undercuts eliminated to make it many times more rigid. This also allows the use of larger mounting bolts.
  • Increased distance between top and bottom liners in the bearing housing to make it as stable as possible eliminating even the smallest amount of rocking
  • An increase in the height of the bearing housing from the top of its inner liner to increase oil capacity, ensuring proper lubrication of the top bearing at all times
  • Double thickness sub-chassis to improve rigidity, reducing flexing and improving control of the relationship between key components

The attached kit of parts, which includes a new inner platter and spindle, is supplied to fit this upgrade. As always with Linn product improvements, new LP12 turntables will incorporate this upgrade as standard.

All Linn products are subject to continuous development programmes and we aim to make similar advances in sound quality in future as we have in the past.

Lingo Power Supply

Date Introduced: 1990 The Linn Lingo is a high precision, direct coupled, power supply designed to sit alongside the LP12 turntable. The Lingo upgrade moves the LP12's performance into a new league, further distancing it from the competition.

At the heart of the Lingo are two very low noise crystal oscillators derived from the Linn Numerik digital studio recording system - one for 33.33 rpm and one for 45 rpm. The switch on the turntable selects the appropriate oscillator, the output of which is fed into a synchronous counter to produce a 50 Hz or 67.5 Hz square wave for 33 rpm and 45 rpm respectively.

As the LP12 motor runs at its quietest when driven with a clean sinusoidal waveform, a precision filter is employed in the Lingo to remove harmonics from the square wave leaving only a pure wave form.

The most uniform torque is delivered from the motor when both phases are driven at ninety degrees with respect to one another. This is achieved by a ninety degree phase-shift network after the filter. The two resulting sinusoids drive two high voltage class A amplifiers, the outputs of which drive the two motor windings.

The Lingo uses 'stall detection' circuitry to feed the motor with a higher voltage for increased start-up torque. When the platter reaches the selected speed, this load-sensing circuitry reduces the power output. From then on the motor just maintains the platter's own inertia to keep it going silently.

A toroidal transformer on the PCB, and a mains filter, give a very high degree of electrical isolation from the mains voltage supply.

Modification History

year serial modification
1993 90582 Cirkus LP12, Cirkus bearing and subchassis upgrade fitted as standard.
1992 88950 Top Plate with additional stud which improves the coupling of the top plate to the Plinth and secures the motor corner.
1991 87672 LP12 mechanics only, LP12 sold as a mechanical assembly only. Three power supply options available: Lingo, Valhalla and Basik. Valhalla and Basik (Basik PSU supplied with 45 rpm adaptor).
1991 87672 Trampolin kit, suspended base board available as an upgrade, solid base board replacing hardboard base
1991 87206 valhalla has motor thrust pad small cap factory fitted (glued in position) to reduce noise level.
1991 87047 lingo has motor thrust pad small cap factory fitted (glued in position) to reduce noise level.
1990 N/A Lingo direct coupled power supply for the LP12, offers low noise oscillators, precision filtering, separate drive for both phases and electrical isolation from mains supply.
1989 81000 Grommets composition changed to a new harder, denser rubber. Improves performance of suspension.
1989 79700 Motor thrust pad, motor thrust pad replaced with stainless steel ball bearing. Reduces motor noise.
1987 79160 Armboard material changed to MDF core, laminated top and underside. Increases rigidity of armboard, creating improved platform for tonearm.
1987 70000 Bearing housing, improved bearing liner material and thrust pad specification. Bearing liner machined to tighter tolerances, thus creating better speed stability. Changed to black oil. Tightened grinding tolerance.
1986 n/a Lid is changed for translucent type.
1984 54100 Sub-chassis, added strengthening bar, spot welded in place. Increases rigidity and strength. late '70s Attached strengthening bar with epoxy glue. Superior bond; increases rigidity.
1984 53000 Plinth, enlarged corner blocks, strengthens and increases rigidity of plinth.
1982 38800 Valhalla power supply, electronic speed control with a sophisticated crystal controlled power supply. Isolates the rotation of the turntable motor from variations in the electrical supply.
1981 32800 Nirvana kit Improved material specification of many integral mechanical components. Improved suspension and stability.
1979 27000 Lid and hinges lid prop removed and hinges changed to spring loaded, self supporting.
1978 23000 Top-plate added two holes for 6 x 0.5 self tappers into wood block
1974 2000 Main bearing liner material changed.
1974 2000 Sub-chassis strengthened by addition of strap, spot welded in place.
1974 2000 Motor control motor control pcb changed from terminal strip to small circuit board.
1974 2000 Mains switch changed from two buttons to single switch with mains neon.
1973 0000 Linn LP12 Sondek introduced