SEIKO EPSON Σ 5000

Commentary

A record player that Mr. Teragaki commercialized in cooperation with Seiko Epson.
It realizes performance not only as a record player but also as as an accurate reader called "surface roughness meter".

The bearing has a structure in which the main shaft rests on four disks, so that the bearing clearance is always 0.
The main spindle has a mirror finish made of SKS steel with hard chrome plating. The contact width of the disk is less than 1 mm and the contact area is reduced as much as possible. In addition, since the hardness of the disk is slightly reduced, the finished surface of the main spindle is transferred as you use it.
The lower part of the main shaft is point supported by carbide balls, and the ball receiver can be easily replaced.

The turntable is finished by diamond processing with an ultra-high precision lathe after sufficient annealing of the brass extruded material. The top surface has a ground Hachigata shape, and the inclination of the main shaft is completely cancelled at the position where the needle tip is traced.
The cross section is designed to prevent standing waves from occurring, and a pure iron drive ring is press-fitted into the outer ring to stop squealing at the interface.
The main shaft and turntable are firmly integrated by flange connection with 4 screws, and the weight is about 12 kg.

The turntable is driven by a unique system using a DC coreless motor and magnetic idler.
The idler contains a surface-magnetized neodymium magnet, which strongly adsorbs to the motor shaft and the drive ring of the turntable and automatically rotates in the most stable position to transmit torque.

The tone arm uses a static balance system.
In Σ 5000, the weight of the head exceeds 400g. The conventional method requires a balance weight of 2.8 kg or more, which makes smooth operation impossible. Therefore, the balance is balanced with a light weight using the principle of the lever.
The arm has a structure in which contact pressure is always applied unilaterally to each supporting point of the arm, and there is no play while obtaining smooth operation. In addition, a rod of high tensile steel is incorporated in the arm beam, and it is firmly integrated with strong compressive stress.

The motor and bearing below the main shaft are consumable parts.

Model Rating

Type	Record player