Pioneer PC-70MC

Commentary

In order to faithfully pick up the limits of high-fidelity reproduction by delving into basic issues such as low mass, broadband, high trackability, high rigidity, and no resonance in order to faithfully pick up the music signal inscribed on the disc.

The left and right channels of the magnetic circuit are independent, and each channel is composed of 3 poles and 2 magnets. The magnets are opposed to each other in the same polarity across the center yoke so that the magnetic flux is concentrated in the center yoke. By this, a larger magnetic flux is generated with a small magnet, and efficient power generation is achieved.

The magnet uses samarium-cobalt, which has a large energy product, and is designed to obtain high magnetic flux density in spite of the wide gap. As a result, high magnetic flux density of 10,000 Gauss maximum can be obtained, and linear and efficient power generation is possible from large amplitude of low sound range to small amplitude of high sound range.
The total weight of the magnetic circuit for both channels is only 0.9g, which is about 1/4 of that of a conventional MC cartridge, making it possible to make a low-mass cartridge.

Micro coils are arranged to correspond to magnets independently on the left and right. The coils have a coreless and bobbinless structure with 99.99% pure oxygen-free copper wires wound in multiple layers.
The impedance characteristics are almost constant up to around 100 kHz, and the sound quality is not affected by changes in the impedance characteristics, so a flat playback sound can be obtained.

Both the magnet and the coil are structurally separated into the left and right channels, respectively, so that interference between the left and right signals is suppressed and excellent channel separation is obtained.

Beryllium is used as a material for the cantilever, and the tapered pipe cantilever is completed by the vacuum deposition method utilizing Pioneer's proprietary precision processing technology.
This is different from the one in which thin plates are rounded and joined together. It is directly molded in the shape of a pipe, so that rigidity is increased and effective mass is reduced, mechanical impedance is extremely low, and reliable tracing is possible.

The PC-70MC uses a one point support system with a clear vibration support point. The rear end of the cantilever is supported by a suspension wire, a damper is provided to clarify the vibration support point, and a damper is provided to clarify the vibration support point. The vibration in the front-back direction that occurs during tracing is reliably suppressed and stable braking is provided.
In addition, taking advantage of the low mass design, the viscous damping of the damper material is set to a minimum to further improve the traceability.

In designing the frame, we have developed a method for measuring dynamic mass using data obtained by directly exciting the cartridge body using computer analysis technology, and based on the know-how obtained through this method, we have implemented a non-resonance design.
The main body of the PC-70MC is made of aluminum die-cast to suppress resonance. Moreover, the vibration system is fixed directly to the frame where the cartridge is attached to the head shell. Thus, there are no intermediate parts and no resonance is generated due to the structure.
In addition, a chuck joint system is adopted in which the vibration system is firmly attached to the aluminum die-cast frame, and the contact point is changed from conventional point contact by screw fastening to surface contact, and adhesion is improved and resonance is prevented.

Model Rating

Type	MC Cartridge
Power generation system	Pioneer System MC Cartridge (Left and right independent 6-pole 4-magnet magnetic circuit, bobbinless coreless twin coil)
Output voltage	0.2 mV (1 kHz, maximum velocity amplitude 50mm/s, horizontal signal)
Output balance	Within 0.75 dB
Channel separation	35 dB or More (1 kHz) 30 dB or More (100 Hz to 10 kHz)
Frequency characteristic	10 Hz to 80 kHz
Compliance	16x10-6cm/dyne(100Hz) 30x10-6Cm / dyne (static)
Internal impedance	38 Ω (10 Hz to 80 kHz)
Load resistance	40 Ω ~ 100 Ω
Cantilever	Tapered beryllium pipe cantilever
Needle pressure	1.2g ± 0.3g
Needle tip	0.2x0.8 mil (Diamond Elliptical Needle)
Needle tip effective mass	0.23mg
Weight	4.0g
Remarks	* Regarding needle replacement At that time, it seems that the exchange was carried out by the store. I don't know if the needle exchange is possible even now. I recommend you to ask the manufacturer. Needle exchange price at that time : ¥ 31,500