Audio Database

The

DIATONE LT-3
99,800yen(around the 1980 time)

Description
 
It is the linear tracking system full auto player which inherited the technology of LT-1 and was developed.

The arm has adopted the linear tracking system which carries out straight line movement of the record board top like a cutting machine. By this system, since the tangential adjusting of a sound track is traced correctly, a tracking error and higher-harmonic-wave distortion can be decreased. Moreover, since there is no generating of an inside force, on the whole, improvement in tracking capability can be aimed at by object contact of the needle point being attained.
The stainless steel wire is adopted as the drive of the move base which fixes a tone arm. This wire united a thin line 0.05mm in diameter from 49, it is performing nylon coating, and it has secured pliability while it acquires the outstanding durability.
About the tracking error, the potential difference of two photo-diode outputs of arm back has detected, and the error angle is suppressed to 0.03 degree - 0.05 degree.

about the vibration accompanying arm base movement, it extracts to two points of stopping vibration which boils and is generated at the move base of an arm to the minimum, and carrying-out-work which does not tell the minimum vibration that occurred at move base in the 2nd to the needle point 、, and is stopping thoroughly.
Then, before being in charge of a design, the mechanism of a move base is modeled, an equation of motion is stood, computer simulation for optimization is performed about the value each component of whose is still more nearly actual, and the concrete design is performed. Furthermore, based on impact center theory, it has determined carefully also about the position of the point driving [ optimal ], and the position of an arm fulcrum.

The electronic-control full auto mechanism is adopted. Thereby, it is controllable only by pushing a manual operation button in operation of all the tone arms. One chip LSI is adopted as a circuit and the quick exact reaction is realized.

The record size automatic detection mechanism by application of an optical system is adopted.
By this system, light is glared from the slanting upper part with a reflector, and it has the structure of leading light to a sensor from the reflector for turntable sheets. According to the size of a record, irradiation/interception of this light are done, and it changes the output of a sensor. This output is sent to a logic circuit and record size is detected automatically.
Based on this detected record size, a needle descent position and a rotating speed are determined automatically.

Since it is operating carrying the quick response function and always detecting the state of an arm lifter or an arm, it is possible to carry out auto operation from every position. Thereby, in auto operation, during a rise, also in /descent, if an arm directs the following new operation with a button, it will shift to the operation immediately.

The feather touch type which uses a microswitch is adopted as button operation.

The muting mechanism which cuts a noise is carried.

In order to suppress a vibration of a tone arm, the weight case and the anti Resonance filter which added the butyl rubber damper are adopted as the structure by a needle pressure knob and main weight. Moreover, by extending the span of a pivot, ガタ of the pipe part was lost and perpendicularity and a horizontal direction have realized high sensitivity.

Stainless steel is adopted as the quality of the material of a tone arm.

OFC (non-oxygen conducting wire) which gave special covering is used for the conducting wire in an arm, and head shell conducting wire.

Different-species metal double structure is adopted as a turntable. It is what laid the stainless steel plate on top of the turntable of aluminum die casting, when vibration occurs on a turntable, a slip arises between two metal, and this is attenuated by making vibrational energy consume.

The Quartz PLL system which controls the number of rotations of a motor by the standard signal of a crystal oscillator is adopted as the drive of a turntable.
Moreover, the high torque DC servo motor of the bearing mechanism finished precisely is adopted as a drive motor.

The cabinet has structure which fixed wooden boards to die casting.


Rating of a mode
Form Full auto player
<Turntable part>
Drive system Direct-drive system
Motor 8 pole Quartz PLL and a DC servo motor
Turntable The product made from 312mm aluminum alloy die casting, 1.5kg
Inertial mass 253kg-cm2
Number of rotations 33 1 / 3 or 45rpm
Number-of-rotations change system Electronic formula (it is a manual change at the time of irregular number of rotations)
Wow and flutter 0.012%WRMS
0.025%WRMS (value of only a rotation part)
S/N ratio 80dB(DIN-B)
<Tone arm part>
Form Static balance, universal straight pipe type
Full length 225mm
Active length 175mm
Tracking error angle ±0.05 degree or less
Needle pressure adjustment 0-3g Direct-reading type (0.1g step)
Head shell The product made from a Magnesium alloy, 6.2g
Cartridge attachment weight range 10-16g
16g-20g (at the time of sub-wait use)
<Synthesis>
Power source AC100V, 50Hz/60Hz
Power consumption 15W
Dimensions Width 485x height 177x depth of 413mm
Weight 15kg
Attachment Overhang gage
45 rotation adapter
Sub wait
Driver