Saturday, December 28, 2013

Langer No.7 Direct Drive Turntable


Drive technology:
Of course we use our new direct drive technology in our turntable. Absolutely low noise, top wow and flutter values and adequate time for speed stabilization, are just a few advantages of the langer-direct-drive. The unique analog drive controller sends an almost flat and very low control voltage to the motor. The motor operates mainly as a high precision platter bearing with a little energy compensation for friction losses.

The platter:
The weight of the platter is almost 3kg. The mass is optimized for best results with our motor and controller technology. The solid rubber mat adds also weight and eliminates platter resonances. In addition it couples the record to the platter.

It is extremely simple and still comfortable to operate the Langer No. 7. There are buttons for speed selection, 33 or 45 rpm. The selected speed is illuminated with an area LED. There is another button for start/stop toggle. The “motor on” condition is also indicated via LED.

The Chassis Design:
The Langer No. 7 has got a sub chassis design. Motor, platter and tonearm are assembled on a solid metal plate, which sits on 4 damper elements. The outside housing works as solid ground. The housing of the “full metal” version has a mass of 20kg! But also the version with fine wood finish has a heavy full metal base plate. The complete turntable is equipped with 4 adjustable full metal stands, for exact positioning in the horizontal.

Tonearm Integration:
A huge variety of 9” tonearms is accepted by the turntable. With special designed adaptor plates, it is very simple to integrate the 3rd party tonearms. The audio cables are guided through holes in the back of the housing. There is also a solid grounding clamp for connection to the amplifier.

The motor design is brushless. It used Hall sensors and an integrated electronic board for commuting the motor coils. This is a must for a smooth motor movement and for elimination of distortion by usual brushes. The motor coils are air core types. So there is no magnetic rest point or hysteresis loss. An optical sensor is used for continuous speed feedback.

As the motor bearing is also the platter bearing, we spent special attention on its design. The radial force is carried by a precision sinter metal bearing. For the axial forces, we spent the motor a bearing bottom out of polyamide. This design guarantees very low noise movement and high precision bearing gap, combined with long life.

The rotor unit is also a sub platter. So it is easy to combine with al kind of platter designs. All motor components are integrated is a solid metal housing, which eliminates all kind of vibration.

Speed Control:
For our "langer" motor, we designed a special speed controller. This controller is an analog design. That means we use an analog signal for the motor speed feedback and compare it with an analog reference. The output signal to the motor is again analog. In combination with a correctly designed platter, the signal to the motor is a simple line, absolutely low level and flat. In normal drive condition, the motor acts just as a precision bearing plus a little energy for the friction losses. Only in start mode or at higher break forces, it increases the drive current accordingly to the needed level. Long waiting times for stabilized platter speed as a compromise for low wow and flutter and low noise, is no longer needed. The "langer direct drive" features both without compromising.