YAMAHA MC-1X/MC-1S

Commentary

MC cartridge which adopted beryllium tapered pipe cantilever by electron beam vacuum evaporation method for the vibration system.

In the MC-1X, aluminum die-cast is integrally molded including the head shell to obtain sufficient strength.
The MC-1S is a universal type with the same vibration system as the MC-1X. It is housed in a strong aluminum die-cast housing.

The cantilever uses a beryllium tapered pipe cantilever.
Beryllium has a density of 1.83 and is 2/5 to 2/3 smaller than the light metals such as titanium and aluminum which are usually used as cantilever materials. Moreover, the rigidity of beryllium is the largest among metals, surpassing that of tungsten. In the development of the MC-1X/1S, the electron beam vacuum deposition method, which is an LSI manufacturing technology, was further advanced and the precision was further improved. As a result, a pipe-shaped cantilever with a taper, which had been impossible to mold until now, was successfully made of beryllium.
This beryllium tapered cantilever is finished in the form of a 35 micron thick pipe with a tip of 0.3 mm φ and a base of 0.6 mm φ.

The stylus uses a special elliptical shape made of square solid diamond and is precisely polished so that the particularly hard crystal axis touches the record sound groove.

A circular air-core coil is used for the coil.
This coil is made by depositing aluminum, which is lightweight and has low specific resistance, on a 70-micron silicon substrate using IC manufacturing technology. It is finished with a 20-turn x2-layer laminate structure. As a result, of 0.03 mg equivalent mass with an outer diameter of 1.42 mm φ and a thickness of 90 microns on a substrate with a weight of 0.33 mg.
The coil substrate, which also functions as an armature, is made of pure silicon, which is extremely lightweight, highly rigid, and has a fast sound propagation speed (9000m/sec). Since it is firmly connected to the cross-shaped support plate, there is almost no unnecessary resonance, and since there is no need for braking by grease, troubles such as grease leakage and solidification are eliminated.

In order to concentrate the cantilever on the vibration transmission function, a root wing system is adopted.
In this method, two IC coils are attached to the base of the cantilever in a wing-like shape with an opening of 90 °. The base of the cantilever is first pressed into the center of the cross-shaped support plate and fixed. A coil of a silicon substrate, which also functions as an armature, is fitted and fixed to the tip of the support plate. Therefore, unlike the case where the coil is located in the middle of the cantilever, it is less affected by the resonance mode of the cantilever, has a small equivalent mass, and is protected from troubles caused by dust during tracing.

A 900 μ m thick butyl-based rubber damper is used for the damper. A cross-shaped support plate with a cantilever press-fitted is embedded in the damper to an appropriate depth and connected. In addition, the four arms of the cross-shaped support plate are embedded in the damper to an appropriate degree, so that it is designed to provide shear braking between the damper and the damper. Thus, effective damping is achieved when and as much as necessary.
Furthermore, to clarify the vibration support point, the cantilever is suspended at one point with a special piano wire, and the rear end of the piano wire is firmly fixed with a thick brass holder.
The butyl-based rubber of the damper keeps the initial performance for a long period of time by minimizing aging and temperature changes, and by combining with the precise structure.

Yamaha's original differential power generation system is used for the power generation mechanism.
This differential power generation system has high power generation efficiency with less distortion due to the yoke less differential magnetic circuit using samarium-cobalt magnet and laminated IC coil.

The magnetic circuit is equipped with a Yamaha yoke less dual differential magnetic circuit in which two pairs of magnets per channel are connected with opposite polarity. This differential magnetic circuit not only exhibits about twice the power generation efficiency compared with a single circuit, but also has a gap of equal width (0.6 mm) with the N pole and S pole facing each other directly. Therefore, the magnetic flux in the operating region of the coil is perpendicular to the coil and the magnetic flux density is uniform. Compared to the curvilinear and uneven magnetic flux density distribution when adjacent at 90 °, the magnetic flux density distribution is much linear.

The magnet uses a samarium-cobalt magnet developed by Yamaha with an energy product of 25 ~ 30M0e.
Adoption of this magnet enables a yokeless magnetic circuit. Although the weight of the magnetic circuit is 0.43g, the magnetic flux density at the coil gap is more than 11,000 gauss (P-P).

Ultra-fine gold wire with low resistance is used for the coil lead wire, and the middle part of the lead wire is fixed to the body with silicon rubber to reduce unnecessary resonance of the lead wire.

The MC-1X has gold-plated shell connector terminals and the MC-1S has gold-plated terminals.

Model Rating

Type	MC Cartridge
Armature	Air-core, thin-film laminated (2 layers) aluminum plate coil
Magnetic circuit	Yokeless, dual differential magnetic circuit
Conversion characteristic	Differential system
Vibration system	One point suspension system
Stylus	0.1 mm Square Diamond Special Elliptical Needle
Cantilever	High purity beryllium, tapered pipe
Vibration system equivalent mass	0.25mg
Braking system	Coupled shear braking system
Housing case	Rigid aluminum die cast structure
Output voltage	0.2 mV (1 kHz, 5cm/sec, Peak45 °)
Channel balance	28 dB or More (1 kHz) 25 dB or More (10 kHz) 20 dB or More (20 kHz)
Electrical impedance	30 Ω ± 20% (Pure Resistance, Balance 20% or Less)
Playback frequency range	10 Hz ~ 20 kHz (Capacity : 60 kHz)
Needle pressure	1.8 ± 0.2g
Static compliance	38x10-6Cm / dyne (25 ° C)
Dynamic compliance	11x10-6Cm / dyne (25 ° C)
Vertical tracking angle	20 ° ± 2 °
Needle tip	8x40 micron special elliptical diamond needle
Weight	MC-1X : 18.5 ± 0.1g MC-1S : 7.8 ± 0.1g
Exchange needle	MC-1X : Body replacement (¥ 31,500) MC-1S : Body replacement (¥ 24,500)