After 70 years in the analog, Nagra is proud to release the Reference Anniversary Turntable, the ultimate dream for analog passionates
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TECHNICAL SPECIFICATION
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”.
PLATTER
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.
CHASSIS AND SUB-CHASSIS
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.
This innovative system provides unparalleled resistance to both self-generated and room/airborne vibrations and resonances. To ensure stability of the floating suspension, the plane on which the suspension functions is as close as possible to the plane of the LP playing surface thus, the “form follows function” height of the suspension pillars. Proof of this concept and its implementation included testing with a high performance, deep bass capable loudspeaker played loudly within centimetres of the turntable as it played an LP. The result was absolutely no breakthrough of vibration or resonance transmission to the highly sensitive cartridge/tonearm interface. Lab measurements confirm a self-resonance of the suspended chassis of less than 3Hz thus guaranteeing freedom from coloration or feedback even at significant listening levels. Overall levelling of the Reference Anniversary turntable is easily accurately accomplished by rotating the massive threaded feet of the suspension pillars.
POWER SUPPLY
Super-cap power supply and super-cap drive unit
The power supply of any state of the art contending turntable system is an extremely critical component. The Reference Anniversary turntable benefits from the massive development process of our state of the art, supercapacitor based, HD PREAMP and HD DAC X external power supplies. While it is almost universally recognised that battery power supplies are far superior to power supplies connected to AC mains, it is not practical to use battery power supplies for higher power consuming audio components. Where practical, however, supercapacitor based power supplies provide all of the advantages of battery based power supplies with the added advantage of accepting and delivering charges much faster and with higher current load and cycle stability than battery based power supplies. In the four year development process of the Reference Anniversary turntable, considerable attention was given to the design and engineering of an HD level, supercapacitor based, external power supply for the turntable system. In addition to the utilisation of supercapacitors in the external power supply, the motor drive system was designed to utilise multiple supercapacitors at the source of demand – the motor drive itself – thus realising the tremendous benefit of having the energy source right next to the demand.
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