Technics EPA-100

Commentary

The universal tone arm was developed in response to the major problem of the pickup system : the damping of low-frequency resonance.

It uses a variable damping dynamic damping mechanism that can appropriately brake low-frequency resonance from the high-compliance type to the low-compliance type, bringing out the unique taste of the cartridge.

One side of the main weight is split and supported by a spring, and the other is floated by the attraction force between two magnets attached to the rear part of the weight and the damping selector. The resonance of the weight is damped by viscous silicon oil and a damping cylinder. By effectively damping the resonance of the entire pickup system, we succeeded in suppressing the resonance to less than half of the conventional resonance.

According to the compliance of the cartridge, the resonance frequency of the main weight can be adjusted by the damping selector at the rear of the main weight, and the braking amount can be set to an appropriate value.

The arm pipe with an outer diameter of 9.5 mm and a thickness of 0.5 mm uses a titanium nitride pipe arm, which is made by hardening titanium, which is lightweight and mechanically strong, with nitrogen. Compared with conventional aluminum pipes, the weight is reduced to 85%, while the mechanical strength and internal loss are approximately 1.6 times greater.

The support structure of the tone arm employs a gimbal suspension system that uses an in-house high-precision pivot bearing for both horizontal and vertical rotation parts. The horizontal and vertical rotation axes intersect at a single point, reducing the initial motion sensitivity and sensitivity differences in all directions of rotation.

Rubies with a friction coefficient of about 1/3 of steel are super-finished into balls with a sphericity ± 0.5 μ and 20 stones are used.
Combined with the gimbal suspension system, it realizes a high initial motion sensitivity of 5 mg.

There was a special balance weight sold separately.

Model Rating

Type	Variable braking dynamic damping system Universal tone arm
Effective bearing spacing	30 mm both horizontally and vertically
Arm pipe	High-strength titanium pipe with special nitriding treatment
Effective arm length	250mm
Total arm length range	322 mm ~ 350 mm
Arm rear length range	66 mm ~ 94 mm
Arm height adjustment mechanism	45 mm ~ 90 mm (Helicoid Part 6 mm)
Overhang	15mm
Horizontal tracking error angle	+ 1.1 ° (30 cm record inner circumference) + 2.1 ° (30 cm record circumference)
Rotational axis sensitivity	Horizontal / vertical, initial motion sensitivity 5 mg
Arm effective mass	22g (Cartridge Weight 6.5g, Needle Pressure 1.25g)
Arm resonance frequency	9.8Hz (Compliance : 12x10-6cm/dyne Cartridge self-weight 6.5g, needle pressure 1.25g)
Arm resonance sharpness (Q)	6 dB or Less (Optimal Adjustment)
Needle pressure adjustment range	0 ~ 3g
Shell Weight	9.5g
Cartridge Mounting Dimensions	JIS Standard 12.7 mm (1/2 inch) Mounting Interval
Shell terminal lug	Lug for 1.2 mm φ, 4-pin terminal
Applicable Cartridge Weight	5g ~ 10g
Arm mounting hole diameter	38 mm φ
Sold Separately : Balance Weight SH-100G1 (¥ 20,000) for EPA-100
Format	Variable braking dynamic damping system
Arm effective mass	25.5g (when cartridge weight is 9.5g, needle pressure is 1.25g)
Arm resonance frequency	9.1Hz (Compliance : 12x10-6cm/dyne Cartridge self-weight 9.5g, needle pressure 1.25g)
Resonance Sharpness (Q)	6 dB (at optimum adjustment)
Dimensions	66 mm ~ 94 mm (Weight Highest Part from Horizontal Rotating Shaft)
To the cartridge weight Balance weight relationship For the EPA-100 Balance weight SH-100G1 SH-100G1 (including auxiliary weights) Cartridge Weight 5g ~ 10g 9g ~ 16g 20.5g ~ 29.5g Cartridge Weight + Shell Weight 14.5g ~ 19.5g 18.5g ~ 25.5g 30g ~ 39g