Original Bang & Olufsen MMC4 Cartridge/Stylus Uk stock ready for dispatch NOW Sounds great Checked on a spectrum analyser, delicate, accurate and precise matching perfectly to its published specification Tracking perfectly with 1.2gram vertical tracking force MMC4 Specifications Description Titanium-bonded elliptical diamond, mounted on a tapered aluminium cantilever |
Courtesy of Beoworld.org MMC stands for 'Moving Micro-Cross'; the patented moving-iron principle upon which all B&O cartridges were based. This unique system employed a cross-shaped armature which, among other advantages, guaranteed exceptional stereo separation since each channel moves on a separate axis. The job of any pickup cartridge is to transform the record's physical profile (groove modulation) into corresponding electrical signals (which are then amplified or enlarged by the amplifier and turned into audible sound waves by the loudspeaker. A cartridge must perform three separate and exacting tasks if it is to do this job successfully. It must function mechanically (the movements of the stylus in the groove); it must function magnetically (using the physical movements to create changes in a magnetic field); and it must function electrically (using the changes in magnetic flux to generate an electrical current). At each stage, one type of energy is transferred into another, quite different, type. And the transfer must be perfect, with no energy lost and none added from extraneous sources. No cartridge will ever reach this ideal unless the Laws of Physics can be repealed. However, by understanding the relationships between the three transfer stages and continually applying refined engineering techniques, B&O's belief was that each stage of cartridge improvement would bring each successive cartridge closer to the ideal.Record wear and the cartridgeIf you take music seriously the value of your record collection is likely to be high. Many of your records are likely to be irreplaceable. You will also know that the signals pressed into your vinyl discs are very fragile indeed. The pickup cartridge can be the disc's worse enemy since an ill-suited cartridge can mark a record for life in a single play. While B&O is aware that cartridge specifications are inter-related, their research shows consistently that Effective Tip Mass (ETM) is one of the major factors affecting record wear. ETM is the equivalent of the amount of inertia the groove 'sees' in moving or accelerating the stylus tip. Consequently, the higher the ETM value, the higher the force required for a given constant acceleration. Obviously, more force results in more wear. Three elements contribute to ETM. The stylus tip (diamond) contributes with its entire weight and mass. The armature contributes between 5 - 20% of its weight and mass; the cantilever around 30%. B&O has been able to reduce ETM substantially by refining these elements and building them into an integrated unit. The result is a system which not only reduces damage to the groove walls dramatically, but also provides exceptional performance at all frequencies. |