Audio Database

The

DIATONE LT-5V/LT-5VC LT-5V:69,800yen(around the 1979 time)
LT-5VC:79,800yen(around the 1979 time)

Description
 
It is a record player of the length type type which adopted the linear tracking system.
There were two kinds of LT-5VC which equipped LT-5V and Diatone original cartridge MM-2 by an alt. phone company a cartridge is not attached to.

A length type structure new as a record player is adopted as LT-5V.
In a common level type player, since the direction of floor vibration is the same as the oscillating direction of a cartridge, when changing the mechanical vibration by trace of a sound track into an electrical signal by a cartridge, floor vibration will be compounded by the play signal and it becomes a howling phenomenon.
On the other hand, in the length type player, the oscillating direction for the direction and cartridge of floor vibration to generate electricity does not interfere, but it has a structure strong against howling.
Moreover, the impression system is adopted as needle pressure. Since the tare direction of a cartridge differs from the needle pressure direction, once it sets it as proper needle pressure, even if it exchanges cartridges, there is almost no troublesomeness of needle pressure readjustment.

The linear tracking system is adopted as a tone arm part. By this system, in order to carry out horizontal displacement of the tone arm the whole fulcrum, it becomes the completely same operation as the cutting machine which minces a sound track to record original recording.

It consists of two, the optical sensor part which detects the degree of perpendicularity of a tone arm, and the actuator which operates a tone arm based on the instructions from a tracking servo circuit, LT-5V. First, the optical sensor has detected the degree of perpendicularity of the tone arm part currently supported in the gravity direction (lower part), and a base portion from the arm base, and the system which tells the output which takes place according to the angle difference to a tracking servo circuit is adopted. The motor for a level drive is correctly rotated by the tracking servo circuit which had an optical sensor which reacts quickly, and high accuracy also in few angle differences.
The optical sensor has the structure of detecting the degree of perpendicularity of a tone arm in engineering, by the output of 2 sets of high sensitivity photo-couplers.

In the tone arm, the short & straight type stainless steel arm is adopted, and in high rigidity, since inertial mass is also low, the partial vibration and the compound vibration have decreased.

The record holder is equipped with the special stopper which combined the spring in order to make a turntable hold a record board certainly. Furthermore, the device is added also to the form of the center shaft connected with this stopper.
Moreover, it is possible to also support a record with curvature firmly by making a turntable sheet into the shape of an earthenware mortar slightly.

The double flywheel drive system is adopted as the drive of a turntable. A moment of inertia is raised combining a flywheel at the back of a turntable, and it is made to drive by PLL and a DC servo motor by this system.
Furthermore, stable rotation is realized by carrying out balance adjustment to one-piece one-piece high precision by a balancing machine.

The optical sensing logic control by LSI which the Diatone developed is adopted as a full auto mechanism.
The light first irradiated from the reflector makes the sensor corresponding to each record size react by a record size automatic detection mechanism. Next, the output from a sensor is sent to a logic circuit. This detected record size automatically, and also the needle descent position at the time of a performance start, the end position of a performance, and number of rotations are also determined.
Moreover, the needle point protection function is carried, and when the record board is not set on the turntable, even if it pushes a manual operation button accidentally, a needle returns to a turntable to an arm rest as it is, without getting down.

The muting function which cuts the unpleasant clicking noise at the time of a record landing is carried.

The optical display which displays a motion of a tone arm on real time by LED is carried.

The tracking monitor is carried in order to check the degree of perpendicularity of a tone arm. When a tracking error occurs, it catches quickly, and warning is emitted by LED.

Internal LSI
Microphotography
Arm
The Record
Structural Record

Rating of a mode
Form Electronic-control full auto player
<Turntable part>
Drive system Double flywheel belt drive system
Motor PLL and a DC servo motor
Turntable The product made from 304mm aluminum alloy die-casting, 1.3kg
Inertial mass 300g-cm-S2
Number of rotations 33 1 / 3 or 45rpm
Number-of-rotations change system Electronic formula (irregular number of rotations is a manual change)
Number-of-rotations fine-tune range ±3%
Wow and flutter 0.045% or less (WRMS)
Signal to noise ratio 65dB or more (IEC-B)
76dB or more (DIN-B)
<Tone arm part>
Form A static balance type and a universal straight pipe
Full length 223mm
Active length 180mm
Tracking error angle ±0.1 degree
Needle pressure adjustment Direct-reading types 0-2.5 g (0.1g step)
Head shell LT-5V: Glass fiber ON special resin, 6.2g
LT-5VC: A cartridge and an integral type (MM-2)
Cartridge attachment weight range 10-20g
<Synthesis>
Cabinet Particle board metallic finishing
Dust cover Styrene resin (attachment and detachment are possible)
Insulator It builds in the leg.
Power source AC100V, 50Hz/60Hz
Power consumption 14W
Dimensions Width 466x height 430x depth of 200mm
Weight 11.5kg
Attachment Overhang gage
45 times diversion adapter
Driver