DIATONE DP-EC1mkII
¥ 128,000 (around 1978)
Commentary
An EC (electronically controlled) full auto player released as a successor to the DP-EC1.
The counter weight of the tone arm has a built-in anti-resonance filter. This anti-resonance mechanism reduces resonance in the 30 Hz to 80 Hz range and improves resolution in the low frequency range.
In addition, stainless steel pipe with high rigidity is adopted for the pipe arm instead of the conventional aluminum pipe, and it is combined with the counter weight with the damper built-in, and the deflection of the pipe part is almost eliminated.
A force is applied to the tone arm in the direction of twisting or pulling the pipe. If the pivot is loose at this time, these forces will be applied to the needle tip and the sound quality will deteriorate. To prevent this, the span of the pivot is expanded, and a full-scale radial ball bearing is used for water plain bearing. This eliminates the looseness of the pipe and suppresses resonance.
The tone arm is driven by two separate motors, one for horizontal direction and the other for vertical direction.
All the conductors in the arm and the head shell are made of pure silver wire with special coating, which reduces DC resistance and improves the sound rise to improve the sound quality in the mid and high range.
The head shell is made of magnesium alloy.
The automatic record size detection mechanism uses an optical system to detect the record size without touching the record.
The principle of this automatic record size detection mechanism is that a reflector emits light from obliquely above a record and guides the light to a sensor corresponding to each record size. The light to the sensor is blocked or emitted depending on the record size, and its output changes depending on the record size. The output from the sensor is then sent to a logic circuit that determines the size of the record. Then, the needle down position, performance end position, and rotation speed of the automatic performance are determined automatically.
In addition, with DP-EC1mkII, it is possible to finely adjust the position of the needle effect on the record board by pressing the button.
The DP-EC1mkII is designed to operate without contact at all times while detecting the state of the arm lifter (up / down) and the horizontal position of the arm, so that it can operate automatically from any position.
Manual operation is possible without switching between Auto and Manual except when the arm is moved by Auto operation.
Equipped with a quick response mechanism, even when the arm is moving up or down in automatic operation, if you instruct a new operation with the button, you can immediately move to the next operation.
A quartz PLL system is used to control the rotation of the turntable. In this system, the rotation speed of the motor is controlled by a high-precision reference signal from a crystal oscillator. The motor also uses a 4-phase 12-pole quartz PLL / DC servo motor with a starting torque of 1.2 kg ・ cm.
The turntable has an outer diameter of 333 mm, a weight of 1.8 kg, and an inertial mass of 353g-cmS.2Turntable is adopted.
With an emphasis on record adhesion, it uses a turntable sheet designed slightly above the mortar. As the material of this sheet, it uses NBR flexible sheet which was selected after consideration of hardness and specific gravity. It has a thickness of 5 mm, specific gravity of 1.5, and hardness of 45.
The electronic flash unit uses the quartz oscillation frequency to generate a signal with a pulse width as short as 1/1000 second and drives the green LE.
By gathering all operation buttons on the front of the cabinet, it can be operated even with the dust cover closed.
The cabinet consists of a die-cast player board combined with a wooden laminate board, and the bottom lid is made of a heavy resinamic material.
Equipped with a muting mechanism to cut noise.
Equipped with a needle tip protection mechanism, the tone arm does not come down even if you lead in when there is no record on the turntable.
Model Rating
| Type | Electronically controlled full auto player |
| <Turntable portion> | |
| Drive system | Direct drive system |
| Motor | 4-Phase 12-Pole Quartz PLL / DC Servo Motor |
| Turntable | 333 mm Aluminum Alloy Die-cast, 1.8 kg |
| Inertial mass | 353g-cm / S2 |
| Number of revolutions | 33 1/3, 45 rpm |
| Rotational speed switching system | Electronic Type (Manual Switching at Irregular Rotation Number Record) |
| Wow flutter | 0.025% or less (WRMS) |
| Signal-to-noise ratio | 80 dB or more (DIN-B) |
| Tone Arm Section | |
| Type | Static Balance Type / Universal S-shaped Pipe Arm |
| Total Length | 320mm |
| Effective length | 227mm |
| Overhang | 14mm |
| Tracking error angle | + 2.9 °, -1.5 ° |
| Offset Angle | 22 ° |
| Needle pressure adjustment | Direct Reading Type 0 ~ 3g (0.1g Step) |
| Head shell | Magnesium Die-cast, 6.2 kg |
| Cartridge mounting weight range | 11g ~ 16.5g 16g ~ 21.5g (when sub-weight is used) |
| <General> | |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 10W |
| External dimensions | Width 470x Height 150x Depth 395 mm |
| Weight | 13.5kg |
| Attachment | Overhang gauge 45 Rotation Adapter Sub x Weight DRIVER Cartridge Spacer (2 Types) Hex Wrench |