TechDAS: Air Force Zero Ultimate Turntable

TechDAS Air Force Zero Turntable
“Currently we have a full product range from the Air Force One Premium, Air Force Two Premium, Air Force III Premium to the Air Force V.

In parallel to the development and releases of these models, a project was going on at TechDAS to bring our dream of the absolute ultimate reference turntable to reality. The goal of the project was to develop a truly groundbreaking product, building on our expertise and knowledge and incorporating new ideas and insights. To achieve this goal, the project had to be cost-no-object. And it had to have whatever technologies would be best suited for sonic performance, no matter how much it would cost. We are pleased to announce it is finally complete, though it took one year longer than initially planned. The result is a turntable weighing 330 kg and measuring 902 (W) X 677 (D) X 335 (H) mm.”
— Hideaki Nishikawa, the Designer


The Platters & Chassis design

TechDAS Air Force Zero TurntablePlatter Base
The Platter Base (35 kg, extra super duralumin) serves as a hub for the air suspension system. This Platter Base has four massive blocks composing the air suspension system mounted on it, and where two tonearms can be fitted. The Platters are made of different alloys and placed on the Platter Base. The air suspension system successfully eliminates vibrations that could transmit from the Platter Base to the tonearm and record surface by having the center of gravity much lower than the supporting point. This concept was key to its design, opposed to a theory that weight acts solely as a barometer to record players as some people believe.

Base Frame
The Platter Base sits on a 100 kg Base Frame made of SUS stainless steel. This Base Frame, which has an enhanced speed of oscillatory convergence with special surface treatment, supports the total weight of 230kg of the Platters, Air Suspension System and Platter Base.

Tonearm Bases
Two titanium tonearm bases are provided. Almost any 9 inch, 10 inch or 12 inch tonearms can be fitted with the exception of non-standard lengths.

Platters
The Platters are designed for the highest level of vibration absorption by combining different alloys. For example, the top layer is made of titanium with surface hardening treatment applied to produce hardness equivalent to hard metal alloy. More importantly, these five layers of platters are held as one with air suction similar to vacuum LP hold-down. This solution allows avoiding metal fittings which could induce mechanical stress.

Air Bearing

The five platters float to the height of 10µm and rotate in absolute silence as one unit. To make this possible, the Platter Base surface is precision machined with a tolerance of less than Sµm at its circumference.

Air Suspension System
The AF Zero has an Air Suspension System consisting of four blocks providing insulation and absorbing low frequency vibrations at the four corners. This air suspension module is uniquely developed by TechDAS and air is supplied from an electric pump to the air suspension modules.


TechDAS Air Force Zero TurntableTechnical features of the Air Force Zero Motor

The first task was to find a motor to drive this gigantic system. By pursuing every avenue, TechDAS finally found some high quality synchronous motors manufactured for tape recorders by the renowned German manufacturer, Papst. These motors proved to be most suitable for their aims, which opened the door to the success of the Air Force Zero project.

The next step was to review and modify the Papst motors so that they could work optimally for the world’s best turntable system. Building on the 3-phase, 12-pole synchronous AC large torque motor, TechDAS developed a customized air bearing and flywheel technologies which are used in driving the motor.

The major features of the Air Force Zero Motor are:
1. High precision rotation with virtually zero wobble due to the combination of high precision metal bearing and air bearing.
2. Enormous inertia generated by flywheel effect.
3. Extremely high S/N ratio achieved by the air bearing.
4. New electronic driving circuitry designed for stable and precise rotation with low vibration.

During a steady state rotation, the driving amplifiers perform smooth rotation without the servo. The servo will be engaged only during the startup process or if the speed is changed by an external force. These technologies results in an exceptional level of rotational precision for a belt-drive turntable.


TechDAS Air Force Zero TurntableDriving System

1. Crystal Oscillator
Reference clock oscillator that provides a clock signal to stabilize rotation frequencies for the motor.

2. Direct Digital Synthesizer (DDS)
This functions as a synthesizer to divide the input clock signal according to the values of frequencies determined by the microprocessor, converting high frequencies to low frequencies so that they will work with the motor. Almost any value of frequencies can be output and precise control of the rotation is possible.

3. Torque Switching Circuit
This circuit switches the voltage to the motor in order to quickly increase the rotation torque to a rated speed during a startup or when shifting the rotational speed of the platter. When a rated speed is achieved and the rotation speed is locked, the torque will then be decreased in order to reduce vibrations even further.

4. 3-phase Signal Generator Circuit
This circuit creates an accurate phase shift to the input signal of 120 degrees to generate 3-phase AC output for the 3-phase motor.

5. Motor Driving Amplifiers
There are three 150W power amplifiers for the respective three phases, with ample current to optimally drive the synchronous motor.

6. Synchronous Motor
The motor is a 3 phase AC motor operating in synchronization with an accurate 3 phase frequency, generated with the 3 phase signal generator circuit. A more common power system for the motors has AC power phase shifted with capacitors. In the latter case, it is very difficult to provide an AC signal output with accurate phase shift due to ageing and errors in the capacitors etc. Such issues can lead to a decrease in torque and an increase in vibration.

7. Sensor
This detects the speed of the platter and transmits the information to the microprocessor.

8. Microprocessor
This controls the motor driving mechanism so that an extremely high precision rotation will be achieved.


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TechDAS Air Force Zero Turntable Preview
The Audio Salon Hosts Event with Hideaki Nishikawa

Maier Shadi, the proprietor of the Audio Salon, has just completed a larger new room to house big systems such as this one. . .You could derive a real sense of the sonic prowess the equipment was capable of delivering in this spacious and inviting room.

The sound—oh,the sound—that the Zero produced in this setup was truly captivating. The noise floor depths were subterranean and the octave-to-octave balance seamless. It was immediately apparent to me that the TechDAS Zero . . . was delivering a fundamentally different approach to vinyl playback. Never have I heard such 3-D presentation of musical notes. Never have I heard voices conveyed through a loudspeaker so convincingly. . .

Read the full review:

Jacob Heilbrunn
www.theabsolutesound.com

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TechDAS Air Force Zero Debut at Audio Salon—First Impressions Stun Listeners

“The Audio Salon’s Maier Shadi recently completed this new showroom in a space that formerly occupied his storage room and it’s among the finest sounding retail display areas I’ve heard anywhere in the world.

. . .

From the first record Mr. Nishikawa played to the final record I played, the crowd was treated to what all in attendance agree was the finest vinyl playback any of us have ever heard and it wasn’t even close.”

 

Read the full review:

Michael Fremer
www.analogplanet.com

The Audio Salon | Santa Monica,‎ CA‎ | 310-863-0863