MMC 1 Needle

History and Information MMC Needle / Pickup

MMC1 was only available as an upgrade / option - B&O's Beogram was only equipped with MMC2, MMC3, MMC4 or MMC5.

MMC1 product specifications Radial Contact Line diamond, mounted on a freestanding sapphire Tracking force - gram 1 Diamond Stylus Cont. line nude Cantilever tube Sapphire Effective tip mass 0.25 mg / mN 30 Frequency 20-20000 Hz = / - dB 1 dB 30 "Channel separation 1000> dB 30 Output mV / cm / s RMS 0.6 Cartridge weight gram 1.6

The late 1940s and early 1950s were an exciting time for recording the production of the world's first fluted micro 33-1 / 3 rpm long play vinyl record (LP) that appeared in 1947 by Columbia Records. They became available to the public in 1949 in the United States and were produced by CBS. In the UK, the first LP recordings were made by Decca two years later in 1951. At that time, all LPs were produced only in mono. It was not until May 1958 when stereophonic records from Pye were produced. However, it was a few years earlier - 1951 - that Emory Cook (1913-2002) made his first LP stereo recordings of the railroad train in the field entitled "Rail Dynamics", which he showed at New York's 1951 Audio Fair. The record he described as "binaural" (not to be confused with today's binaural media) and consisted of two separate channels cut into two separate tracks running side by side. Each track requires a needle and each needle is connected to a separate amplifier and speaker. The set-up was intended to give a demonstration at the fair in Cook's Cutters instead of selling them. But soon after, the demand for such recordings and equipment to play grew, and Cook Records began producing such LPs, commercially. He recorded a wide range of sounds, ranging from railway sounds to thunder.

The first stereo pickup was SP1 which Bang & Olufsen produced played early (true) stereophonic recordings and was one of the first to exist in Europe. It was only surprised at Garrard's post that released his own model - the GCS10, at the time when stereophonic records were introduced. The SP1 Needle / Picup was the first in a series of Bang & Olufsen needles manufactured for the company's record tire today. At that time, there was no standard as such for playing vinyl micro-track recordings. It was Bang & Olufsen who paved the way with the introduction of SP1 and 15 ° tracking angle for stereo recordings, later as a world standard.

MMC Needle / Pickup is a solid example of Bang & Olufsen's pursuit and execution of superior design and engineering. "MMC" stands for Moving Micro-Cross, a principle design that integrates all components - coils, magnet, console and pen and became the patented principle on which all B&O needles were based. MMC is designed to produce the finest separation of the track and accurate reproduction of music.

Using this principle a very small fixture was placed over four small magnets. In playing a disc, the luminaire is moved with extremely small degrees. An induced current caused by this motion is then relayed to the mmc cartridge contacts. It was precisely this electrical current that was amplified and connected to power amplifiers, which allowed users to hear their Vinyl records.

Moving Micro-Cross (MMC) cartridges

MMC cartridges were manufactured by Bang & Olufsen as fully integrated units. This means that the elements were matched, balanced and sealed at the factory. Using a computer-aided testing program, each sealed unit meticulously tested and its performance information automatically recorded and included with each MMC needle. The information provided includes output voltage, relative voltage output (channel balance), channel separation and frequency response. Individually-calibrated frequency response curves were also provided with the higher specified MMC 20cl cartridges.

Unlike the later MMC types where the pen and components were combined, the pen of the SP interval was intended to be removed and replaced. In this way, music lovers could buy a pen (or measuring tips) relevant to their needs. Suitable diamond-shaped measuring tips can be purchased for 78 variants, monophonic records and micro-tracks stereophonic in the late 1950s.

The MMC design was invented and patented by Bang & Olufsen. Because it often uses a special mount, it can be used mainly in Bang & Olufsen turntables (which also cannot use another type of needle). Apart from being manufactured for Bang & Olufsen mounting systems, the SP12 and SP14 were also available in standard 1/2 "mount or with simple plug-in, light connectors. It was these contacts that allowed a user to mount a Bang & Olufsen MMC on When buying, Bang & Olufsen MMC needles could be used "straight out of the box" and mounted directly on a suitable tone arm without the need for any other extra bracket.

MMC is a moving iron design. Magnets and coils are stationary while the micro cross moves with the pen, thereby varying the distances between the arms of the cross and the magnets. The design obviously gives more freedom about the magnet and the coil mass (compared to MC and MM needles). For example, the MMC20 range (released in 1978) uses four coils wrapped around magnetic cores with 1200 turns each. Minimizing the moving mass also reduces wear on discs.

Bang & Olufsen maintains that the MMC principle enables superior channel separation, since each channel's movements are shown on a separate axis.

pick-up

A magnetic cartridge is a converter used to play a gramophone disc on a disc. Its task is to convert mechanical vibrational energy from a stylus riding in a spiral record track to an electrical signal which is then amplified and then converted back to sound with a speaker system.

The first electric pickup was developed around 1925 and used a piezoelectric crystal of quartz, which is stimulated by a stylus made of sapphire or diamond. Today, the magnetic cartridge is the most common form of sound recording used and came into use in the 1950s, after the introduction of magnetic cutting heads around 1945. Compared to previous systems, the Needle Microphone provides improved playback fidelity, and reduces record wear by tracking the track with lighter pressure , but with higher output voltage.

In high-fidelity systems, crystal and ceramic mics have been replaced by the magnetic cartridge, either with a moving magnet or a moving coil. Magnetic cartridges provide much lower tracking forces (and thus damage the record much less), but also have a significantly lower power than a crystal or ceramic pickup, in the range of just a few millivolts, requiring greater amplification.

Branch

The cantilever is responsible for mechanical connection of the pen (which actually touches vinyl) to the electrical converters and has previously been manufactured from one of several materials:

Aluminum (most common). Sometimes solid and sometimes rolled from a thin sheet to reduce the mass.

Boron

Beryllium (used in Shure V15 wagons, now no longer available due to toxicity problems during manufacture)

Gold-plated metal (usually aluminum)

The primary technical consideration in the choice of metal used is its mass, followed by its mechanical deformation properties. These can affect freely mounting different resonance properties.

styli

A pen is the piece that actually touches vinyl and traces its modulations. It is usually the only component of a turntable that really "goes bad" over time and needs to be replaced, usually with one assembly, or the entire cassette.

Measuring tips are now univerally made of diamond. No other material is as hard or durable. Worn measuring tips develop polished facets that act as chisels on vinyl, causing permanent signal damage. A diamond pen is generally worn out after somewhere between 200 and 2000 hours of use. Poorer materials (sapphire, osmium) will wear out much faster - possibly within 1-50 hours.

The most important stylus characteristic is how it is cut, which determines the profile of the pen on the groove. This measurably and audibly affects the signal quality, tracing power and pen life. If the pen touches a large area of the disc, a greater tracking force is required to exert the same pressure on the surface, which also reduces the life of the pen. If the surface is oriented horizontally rather than vertically - if it covers more of the track radially - then the high response rate is compromised. On the other hand, a pen with a very small contact area tends to be very sensitive to proper alignment and tracking power, and is not as user-friendly to configure.

The easiest way to cut a pen is spherical. A clean spherical cut is pathologically poor and never seen for Microgroove records. Rather, a pen is cut conically, with a spherical tip. These generally have the worst frequency response and a short lifetime. But some high end cartridges - especially the legendary Denon DL-103 - still use a tapered tip. Most DJ cartridges use tapered tip measuring tips

The pen can be cut into an ellipsoid shape so that the contact area forms an ellipse. These are very common in audiophile cartridges

Finally, there are a number of different cutting elements in connection with the idea of having highly eccentric, vertically oriented contact surface on the post. These include names such as "fine line", "micro line", "shibata" etc and which are also common for high-end audiophile cartridges.

It is worth noting that quadraphonic systems from the 1970s - which required much more signal bandwidth than stereo - used fine line or Shibata measuring tips