The top of the range cartridge from B&O, this boasted a single crystal sapphire cantilever and a Contact Line stylus derived from the Pramanik stylus of the MMC6000.
This cartridge was well thought of by many outside the normal B&O user base and was favourably reviewed in many magazines. It achieved something not many B&O products ever managed – it was described as offering value for money!!
Prior to the release of MMC1 – 5 cartridges, Bang & Olufsen had the following MMC range of combined styli and cartridges:
MMC cartridges were available with standard ½” mounting brackets, or with easy plug-in, lightweight connectors. These enabled you to mount MMC cartridges onto non-Bang & Olufsen arms. The cartridges plugged directly into Beogram pickup arms without additional mounting gear
MMC 20 S was a stereo cartridge with a spherical framed diamond
MMC 20 E was fitted with a framed elliptical diamond which has a high polish
MMC 20EN had a naked elliptical diamond, mounted on a tiny tapered cantilever
MMC 20 CL utilised a Contact Line naked diamond mounted on a single crystal sapphire cantilever. This shape ensures maximum groove contact. This was the most highly-specified cartridge in the MMC 20 range
In 1958, Bang & Olufsen introduced the first stereo pickup cartridge ever made in Europe. This was called the SP1. Since then, many design innovations and the creative use of new materials have kept B&O’s cartridges at the forefront of audio technology. By 1979 – 80, Bang & Olufsen’s cartridges were represented by the MMC 20 series. 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. The MMC20 series therefore represented the closest that modern technology at that time, could possibly afford.
Record wear and the cartridge
If 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.
Bang & Olufsen cartridges have always been highly acclaimed for their low ETM values. The ETM of the MMC 20CL is a mere 0,3mg and in the standard MMC 20 range,, only 0,5mg.
MMC cartridges were manufactured by Bang & Olufsen as totally integrated units. This means that the elements were matched, balanced and sealed at the factory. Using a computer-supported testing programme,, each sealed unit was meticulously tested and it’s performance information automatically registered and packed with each cartridge. The information given included output voltage, relative voltage output (channel balance), channel separation and frequency response. Individually-calibrated frequency response curves were also supplied with the higher-specified MMC 20CL cartridges
The MMC20EN was the standard cartridge fitted to the top of the line Beogram 4002 and 4004.
It was a development of the very successful MMC4000 and retained the naked elliptical diamond stylus seen on that model. A fine tapered cantilever was also fitted and provided excellent performance.
Prior to the release of MMC1 – 5 cartridges, Bang & Olufsen had the following MMC range of combined styli and cartridges:
MMC cartridges were available with standard ½” mounting brackets, or with easy plug-in, lightweight connectors. These enabled you to mount MMC cartridges onto non-Bang & Olufsen arms. The cartridges plugged directly into Beogram pickup arms without additional mounting gear
MMC 20 S was a stereo cartridge with a spherical framed diamond
MMC 20 E was fitted with a framed elliptical diamond which has a high polish
MMC 20EN had a naked elliptical diamond, mounted on a tiny tapered cantilever
MMC 20 CL utilised a Contact Line naked diamond mounted on a single crystal sapphire cantilever. This shape ensures maximum groove contact. This was the most highly-specified cartridge in the MMC 20 range
In 1958, Bang & Olufsen introduced the first stereo pickup cartridge ever made in Europe. This was called the SP1. Since then, many design innovations and the creative use of new materials have kept B&O’s cartridges at the forefront of audio technology. By 1979 – 80, Bang & Olufsen’s cartridges were represented by the MMC 20 series. 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. The MMC20 series therefore represented the closest that modern technology at that time, could possibly afford.
Record wear and the cartridge
If 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.
Bang & Olufsen cartridges have always been highly acclaimed for their low ETM values. The ETM of the MMC 20CL is a mere 0,3mg and in the standard MMC 20 range,, only 0,5mg.
MMC cartridges were manufactured by Bang & Olufsen as totally integrated units. This means that the elements were matched, balanced and sealed at the factory. Using a computer-supported testing programme,, each sealed unit was meticulously tested and it’s performance information automatically registered and packed with each cartridge. The information given included output voltage, relative voltage output (channel balance), channel separation and frequency response. Individually-calibrated frequency response curves were also supplied with the higher-specified MMC 20CL cartridges.
This cartridge was in many ways the replacement for the MMC20EN as it had a tapered cantilever and naked elliptical stylus.
It was fitted as standard to the Beogram 6002.
This could be regarded as the standard cartridge in the range and was fitted to many decks as standard.
In many ways a replacement for the MMC20E, it offered good performance at a most reasonable price
The most basic of the range, this cartridge was available to be specified for those decks not fitted with a cartridge as standard such as the Beogram RX.
It could be differentiated by its cantilever which was a straight non tapered aluminium tube.
Beomaster 2000 was an advanced 2 x 25 watts RMS receiver with Long, Medium and FM band radio coverage. Four FM stations could be pre-set for instant recall. There was also provision for pre-setting one AM station.
The low-distortion stereo amplifier included a new feature unique to Bang & Olufsen. It was called Automatic Power Handling Control (APHC). This was a technique whereby the dynamic range and power parameters of the signal were continuously monitored, and if their combined effect threatens to cause amplifier clipping or damage to the speakers, the APHC circuit instructed the set’s microcomputer to turn the volume down to a safe level.
All primary functions were operated by finger-tip contact on the Beomaster’s Sensitouch control panel. There were no knobs or buttons to press. The status of all controls was shown on an illuminated display panel. Secondary controls were protected beneath a self-opening lid that was released by touching the unit’s front edge.
Beomaster 2000 could be made up as part of the Beosystem 2000, when linked together with other compatible Bang & Olufsen products. The receiver was designed by Jacob Jensen and was a direct descendant of Beomaster 2400.
The Beomaster 4500 radio/amplifier received both FM and AM radio and was your communication link to the other sound sources in the system. Its operation was simplicity itself with an illuminated menu presenting all the options available. 20 radio stations could be pre-set providing you with instant access together with automatic fine tuning.
The 2 x 55 watt/8 ohm amplifier had a newly-developed, well-balanced interplay with the power supply which gave the output extra strength. The power reserve encompassed the entire frequency range and gave stable sound quality no matter what the volume. Beomaster 4500 also had automatic power handling control that prevented overloading, no matter how many loudspeakers were connected, as well as a special loudspeaker socket which ensured optimal utilisation of BeoLab active loudspeakers.
Beomaster 4500 could be used as part of the Beosystem 4500 hi-fi system and could be controlled via a Beolink 1000 remote control terminal. Later models of Beomaster 4500 could be controlled by the two-way Beolink 5000 and had the extra benefit of programmable timer functions (note that only Beomaster 4500 models with a software version of 2.1 and higher were able to handle two-way communication as well as the timer function.)
Long, medium and FM wavebands were featured on this high-technology 2 x 55 watts receiver that served as the heart of Beosystem 5000 introduced in 1983.
A frequency-synthesized tuner with automatic fine tuning and two-speed manual drive all contributed to fast, accurate location of radio programmes and superb reception quality. Nine station frequencies (on any combination of wavebands) could be stored in the Beomaster’s microcomputer memory for instant recall.
The low-distortion stereo amplifier included a very advanced feature, unique to Bang & Olufsen: Automatic Power Handling Control. This special circuit continuously monitored the dynamic range and power of the signal and instructed the microcomputer to decrease volume if the combined effects of these two parameters threatened to cause amplifier “clipping” or damage to the speakers. This type of overload became increasingly common since the introduction of the Compact Disc, which can produce signals of enormous dynamic range, but it could not occur in Beomaster 5000.
An internal, variable-speed fan ensured the proper dissipation of heat, even when the Beomaster was used in a stack format. Direct operation of all primary functions was available on the Beomaster itself should the Master Control Panel not be to hand. These controls were located beneath a hinged cover which sprang open at a touch
Beomaster 5000 had no visible controls. Normal operation was by means of the Master Control Panel – a slim, table-top keypad that gave chair-side access to all functions including microcomputer programming and storage, timer facilities, status check, day and clock display, volume, tone and stereo balance adjustments and control of all sound sources. A programme-sequencing facility allowed you to pre-plan a whole evening’s listening composed of record, radio and cassette music in any order and combination. Once set, this “command performance” would play continuously as instructed without further use of the controls
