Nagra Reference ANNIVERSARY TURNTABLE
In 2021, Nagra celebrated its 70 year anniversary. Founded in the pursuit of excellence in sound recording and sound reproduction, Nagra has a rich history of producing some of the world’s best analog recording and playback devices. Nagra now added to this remarkable legacy of products with the introduction of its first turntable and tonearm system.
Drive unit
The heart of the Reference Anniversary turntable is its motor drive system. For some time, it has been recognized that multi-motor drive systems enhance the speed stability of a turntable’s rotating platter. The Reference Anniversary turntable employs dual high precision, Swiss made, decoupled, brushless DC motors. This arrangement optimizes both torque and speed accuracy. This massive motor drive system weighs 11.2 kg/24.6 lb. Expect additional details once the patent process is underway.
Speed stability
In addition to the innovative two motor system, the turntable features a well thought out technology for absolute speed calibration. An accelerometer monitors the floating chassis to ensure that it is absolutely stable otherwise calibration does not take place. Calibration is done over a 20 second window during which time the platter’s speed is precisely calibrated during actual playback (stylus in groove). During this 20 second cycle the platter’s speed is compared with a high precision quartz reference. Any deviation from this absolute speed reference is corrected accordingly. An easy to read, distinctly Nagra Modulometer on the turntable’s front control panel makes calibration (and pitch control) simple. During listening no active speed control is employed. While listening, the motors are only running in a closed loop mode. By eliminating active speed control the “cogging” and associated ill effects on image stability generated by such active systems is avoided.
Reel to reel inspired belt system
Attention to detail even extended to the belt used in the motor drive. For this essential part we took inspiration from the iconic Nagra IV-S tape machine. Because the original supplier of these belts is no longer in existence, we undertook a chemical analysis of the belt composition and have faithfully reproduced this high performance part. We have decided to pay tribute to Nagra’s analog recorder legacy by calling Nagra’s LP drive “Nagra IV – LXX caliber”.
Aerospace material platter
Another critical component is the turntable platter itself. It is this component which intervenes as the interface between the LP and the motor drive. In this case, we exhaustively researched material science. This search led us to aeronautic/space alloys and specifically to a highly specialized, very high density (60% more dense than titanium), non-ferrous alloy with extreme damping properties. This alloy is called EXIUM® AM. It was developed by a French company after a special request of the CNES (equivalent to NASA in France) and in collaboration with the famous Ecole des Mines de Paris. To produce usable material, the alloy, in molten form, must be spun in a centrifugal casting machine.
From this stage it is precision CNC machined into the exacting specifications of the Reference Anniversary turntable’s 6.5 kg/14.3 lb. platter. The end result is a platter that is extremely inert and the first ever audio component to be produced using this Exium® AM alloy
Watchmaker tribute caliber
While sonics clearly rule the day in any Nagra product, where there are opportunities to address aesthetics without compromising sonics, we do so. The Reference Anniversary turntable’s platter’s absence of resonance presented such an opportunity.
Inspired by timepieces from the Swiss high end watch industry, we were able to incorporate an antistatic, 22 mm/.87 in. thick, transparent methacrylate surface to the platter. As in a “skeleton” watch case, this allows the marvel of engineering that is the Reference Anniversary turntable’s motor drive system to be visible. Also, as in the inspiration watches, the words “Swiss Made” are engraved on the caliber. Likewise, parts of the drive mechanism appear in both “Côtes de Genève” or Damaskeening and “soleillage” finishes. Additional engraving includes a reference diagram of the drive system’s belt path, importantly acknowledging our founder, Stefan Kudelski’s, genius, as well as Swiss horologic expertise.
Precision mechanics bearing
Beneath the platter is a sub-platter and shaft/bearing system whose most notable features include a subplatter machined from high strength aluminium. A phenolic interlayer is applied atop the sub-platter for resonance decoupling. The transition from sub-platter to the shaft/bearing system is accomplished via a machined brass adapter which is re-machined in mounted form for tightest tolerances. The shaft/bearing housing is machined from spheroidal graphite iron. The ultra precision shaft is fabricated from induction hardened steel which is subjected to a centuries old watchmaker’s super finishing procedure. The shaft bushing is machined of sintered bronze and high temperature/pressure impregnated with oil for maintenance-free operation. The bearing is comprised of stacked carbide balls which have been subjected to the highest polish grade possible.
Non resonant chassis
The backbone of the Reference Anniversary turntable can be considered the chassis and sub-chassis. In this case, massive plates of aircraft grade aluminium and phenolic have been precisely CNC machined to form a low resonance, high rigidity, layered structure of aluminum/phenolic/aluminum preventing sound coloration from the system’s mechanical parts.
Floating suspension
Integral to the performance of any ambitious turntable system is its suspension. In this case, Nagra engineers devised a unique solution which outwardly mimics the suspension systems of both our HD PREAMP and HD DAC X. Internally, however, is found an ingenious system combining both mechanical and hydraulic principals. The substantial suspension pillars employ both a spring mechanism and a highly viscous fluid contained in a “diver/chamber” configuration which, when combined, provide suspension and displacement in three dimensions.
| Weight: | ~80 kg – ~176 lbs |
| TURNTABLE Dimension: | 662 x 452 x 267-281 mm (26 x 17.8 x 10.51-11.06 inches) |
| TURNTABLE PSU Dimension: | 438x 414 x 121-130 mm (17.2 x 16.3 x 4.7-5.11 inches) |