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 was the cartridge specified for the Beogram 3400 and had a Shibata profile diamond. This is quite a rare cartridge to find these days as many 3400s did not have the CD4 decoder fitted and hence did not require this cartridge..
Beocenter 2800 was a unique combination of FM/AM tuner, a 2 x 25 watts RMS hi-fi power amplifier and record player. The tuner section offered Long and Medium wave reception as well as FM. There were facilities for pre-setting the four FM stations you listen to most frequently. Ceramic filters, AFC, split-supply output and a phase-locked loop decoder were some of the features that ensured outstanding reception and reproduction of even distant stations.
The record player was fully automatic – one master switch controlled all operations. The anti-skating device was built into the arms suspension and worked automatically. Electronic Servo Drive (ESD) ensured constantly correct speed. There were sockets for tape deck, two sets of stereo speakers and headphones.
This was a compact, space-saving unit which was easy to use thanks to automatic circuits and logical controls. Beocenter 2800 could be made up as part of the Beosystem 2800, when linked together with other compatible Bang & Olufsen products
Beogram 1500 combined ease of operation and advanced technology in a simple, straightforward way. All its operations were controlled via a single button.
Another advantage of this totally integrated design was its immunity to external shock and vibrations. The electronic servo drive system ensured correct turntable speed at all times. The low-mass arm had built-in bias compensation, and the MMC 20S pickup tracked at only 1,5 grams.
The unique pendulum spring suspension helped make the Beogram range of record players immune to the external shock and vibrations which would cause most other record decks to mistrack and damage the record groove.
Beogram 1500 could be made up as part of the Beosystem 1500, when linked together with other compatible Bang & Olufsen products.
This deck was the basic model of its time but the inherent design of this deck meant that the performance was extremely similar to the top of the range radial decks. Very easy to set up and simple to use, a true bargain buy in later years.
Beocord 1900 equalled Bang & Olufsen’s top-of-the-line cassette deck (Beocord 5000) in terms of specifications and performance, but it but it did not have the same wide range of facilities and operational refinements.
This does not mean that the Beocord 1900 was difficult to operate. On the contrary, the slanting front panel which contained all the operational facilities made the set’s controls handy and easily accessible. The cassette eject mechanism was air damped so that delivery was gentle and controlled. Two large VU meters enabled accurate setting of recording levels.
The microphones socket was placed discreetly under a sliding panel together with a balance control which enabled signal level adjustment in both channels. All the features which characterised high quality and high performance levels in cassette decks were incorporated. These included a combined recording/play-back Sendust tape head and Dolby B Noise Reduction circuits.
Beocord 1900 used precision techniques that ensured stable tape drive and the highest standards of recording and playback. Yet despite its comprehensive facilities it was easy to use and harmonised comfortably with many different Beosystems.
Beocord 1900 could be made up as part of the Beosystem 1900 or Beosystem2400, when linked together with other compatible Bang & Olufsen products.
When you used metal tape cassettes in the Beocord 8000 you obtained the same high quality sound you were used to from a good gramophone record. Careful choice of components and materials, creative engineering and technical excellence all made this possible.
But superb sound reproduction was only one of the benefits you got from this advanced cassette deck, which replaced Beocord 5000. Of equal importance was the fact that time, through Beocord 8000, came to the cassette deck. Bang & Olufsen used it to measure tape consumption. Quite simply, instead of using meaningless digits, minutes and seconds were used instead. This allowed you to locate specific tracks of music easily and accurately for immediate replay. Just tell the Beocord 8000 where to start, in minutes and seconds and let the set’s microcomputer do the rest.
This feature also helped you plan recordings and thereby ensure maximum use of your tapes. During play, Beocord 8000 measured and displayed the exact amount of tape consumed so that you always knew how much playing time was left on the cassette. And the Beocord wouldn’t let you make mistakes: if you gave incorrect instructions, reject signals flashed on the set’s display panel. The microprocessor which made the real time counter possible was also used to provide a digital clock for timer recording. In normal use the clock did not show on the display, but it could be programmed to start the tape either playing back or recording any time within 24 hours.
The button marked ‘RETURN’ afforded great convenience during recording. Together with the automatic tape position indicator, it enabled you to edit your tapes electronically. The split-channel Peak Programme Meter eased the setting of recording levels and was extremely accurate. It indicated the actual signal that was being fed to the tape, for each channel, rather than that which was being received at input.
Underneath the brushed aluminium panel was the cassette compartment, sliders for setting recording level, an independent slider for adjusting volume level on headphones, facilities for timer programming and adjustments for secondary functions.
For example, you could instruct Beocord 8000 to make recordings of radio programmes while you are out. In short, everything was done to ensure total listening pleasure in terms of sound reproduction and convenience.
Beocord 8000 could be used as a stand-alone tape cassette recorder or as part of hi-fi systems such as Beosystem 6000 or Beosystem 8000.
Beocord 1500 matched several Beomaster receivers in design, concept and performance level. It was also technically compatible with non-Bang & Olufsen products. If you simply wanted to record and play back cassettes without any extra refinements or facilities, this deck was for you.
The slanted control panel was logically planned and really simple to use. The VU meters and sliding input control made the setting of correct recording levels easy and accurate. The 3-digit tape counter had a memory function that helped you locate the start of a particular passage of music.
Quality recording and playback was further ensured by the super Permalloy tape head, highly stable motor/drive system and Dolby B Noise Reduction circuit.
Beocenter 4600 was a multi-way combination unit incorporating a 2 x 25 watts RMS AM/FM receiver, an easy to use hi-fi cassette deck and an automatic record player. The lightweight arm had built-in bias compensation and carried Bang & Olufsen’s MMC 20S pickup cartridge with spherical diamond stylus.
The AM radio covered long and medium wavebands. Outstanding reception quality and high selectivity was secured by an Automatic Gain Control circuit, active noise suppression and hybrid filters.
The FM tuner was highly sensitive. Four stations could be pre-set for subsequent instant recall. The hi-fi cassette deck had all the features and qualities normally expected only in a separate deck:
* 3-digit counter with memory function
* electronic tape stop at end of play
* Dolby B Noise Reduction
* chrome or normal tapes could be used
The super Permalloy tape head was hard-wearing and had a long, useful lifetime. The record player too was automated: all functions were controlled by a single button. The anti-skating device worked automatically too. Bang & Olufsen’s MMC 20 S pickup cartridge with a spherical diamond was an integral part of this unit. Two Beovox S40 speakers complete this system if this was your choice.
If space was limited in your home but you still wanted top-class sound reproduction from your hi-fi, Beocenter 5000 was the perfect answer. It offered high-technology performance from radio, records and cassettes, yet measured only 72 x 38 x 9,5cm. Each sound source could compete on merit with more expensive ‘separates’. The three high-performance components were integrated together into a single unit to give the best of all possible worlds.
The 2 x 40 watts RMS amplifier meant high power with minimal distortion – less than 0,1% at full output. The automatic record deck had a low-mass, low-inertia tone arm carrying an MMC 20E pickup and a precision-built electronic servo drive system for perfect speed accuracy. The cassette recorder was capable of the highest performance levels as it included Dolby Noise Reduction circuits, metal tape facility, automatic ferric/chrome selection, Sendust tape head and 4-digit electronic tape counter. The radio covered Long, Medium and FM bands, with five pre-set stations offering instant, press-button tuning.
Beocenter 5000 offered the same musical facilities and powerful 2 x 40 watts RMS output as Beocenter 7002. The two models were identical in the matter of sound quality too, but only the Beocenter 7002 had Bang & Olufsen’s very advanced timer-track location and remote control systems. The black anodised lid of its cassette compartment further differentiated Beocenter 5000 from the 7002.
