Release Date: 1977

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BeoMaster 4000

Bang & Olufsen BeoMaster 4000

The amplifier section of this receiver had outstanding technical data: harmonic distortion was less than 0.1% at maximum power output and 0.06% at 50 mW. Frequency range was 20-30.000 Hz and effective bandwidth 10-35.000 Hz.

Frequency correction facilities were the LOW filter which reduced rumble on records (12 dB per octave at 80 Hz) and the HI filter which damped hiss (12 dB per octave at 4000 Hz). With the LOUDNESS control you could switch between objective and subjective linear reproductions. Beomaster 4000 had facilities for stereo and ambio reproduction. There were sockets for a record player and two tape-recorders, one allowing A\B monitoring. The headphone connection was placed on the receiver’s front. All inputs could be adjusted to give equal volume from all programme sources. The FM section had six pre-set stations. A light indicator assisted accurate tuning and an illuminated meter indicated the strength of a station. Field effect transistors, ceramic filters and integrated circuits were used.

When combined with a built-in record deck, the music centre was known as Beocenter 3500.

Receivers and amplifiers with the ambio function were products which, apart from stereo, could also reproduce the ambience or sound information of a room. Ambient information was included on most stereo vinyl recordings but could not be reproduced by a sound system with two loudspeakers or an ordinary stereo amplifier. Bang & Olufsen systems with the ambio function had facilities which electronically subtracted the difference signal (i.e. the difference between left and right channels) which contained ambient information. This information was fed into two extra loudspeakers which were placed as side speakers in a room. Ambiophony was an extension of stereo reproduction and enhanced the sense of realism. It could be used with nearly all stereo programme materials.

“Ambio is an extension of the type of sound reproduction known today as stereo.

Ambio is reproduced through four loudspeakers – two more than required for stereo.

Ambio is sensed as being more spatial and acoustically more life-like than conventional stereo. The sound picture has greater depth because you get the added feeling of being present of the concert hall, listening to the actual performance. Ambio is based on the principle that in the concert hall you not only receive sound impressions directly from the performing group, you also get reflections from the wall and ceiling. The spatial sensation is instrumental in providing the auditory experience and even a two-speaker stereo system will not bring it out fully. And you cannot accomplish the effect by connecting additional speakers to a conventional stereo amplifier because you still have the same left and right front signals merely distributed to more speakers.

In the Beomaster 4000 the left and right channels are subtracted from each other electronically and the resulting difference signal contains a certain amount of spatial information which is fed to the two new side speakers.

Many existing stereo records, FM broadcasts and tape recordings contain this spatial effect to a greater or lesser extent. In a concert hall, room acoustics will be recorded together with the actual programme material, appearing as time-delayed signals in both left and right channels. Recordings made in a strongly damped studio contain few time-delayed signals and the spatial sensation will therefore depend on how the producer mixed the sounds from the various instruments, perhaps adding acoustical effects by electronic means.

Multi-channel records such as SQ records, which are intended for use in a four-channel matrix system in order to bring out the sound effects , can be played successfully through the Beomaster 4000.

A good quality stereo turntable will provide ambio reproduction of both stereo and SQ records through your Beomaster 4000″

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BeoCord 5000 (1975)

Bang & Olufsen BeoCord 5000 1975

Beocord 5000 was a superior cassette deck with a Sendust tape head, dual capstans and a special servo drive system which secured low wow and flutter-data. Electronic recording level indicators (Peak Programme Meters) and the Fade in/Fade out functions facilitated exceptional recordings of the most demanding types of music. An automatic demagnetizing device helped ensure optimum signal/noise ratio at all times.

A Hall generator secured the most reliable automatic stop at the end of play. Because it worked electronically it was superior to mechanical systems which are always subject to wear and tear, stress and strain. Naturally Beocord 5000 incorporated Dolby B Noise Reduction circuits. You could also switch from fast forward to fast rewind, or normal play, without endangering your tapes or damaging the drive mechanism.

Despite these technological refinements Bang & Olufsen still didn’t forget the greatest advantage of the compact cassette – that of convenience. That’s why Beocord 5000 was so easy to use. The logically-arranged easy-touch buttons were clearly marked to aid simple, problem-free operation. An illuminated read-out panel told you the operational status of the deck at all times. The display could be read through the black Perspex cover which protected the cassette housing against dust. The unit had two peak programme meters which reacted faster than conventional VU meters in registering recording level and thus ensuring optimum recording quality.

There were two main design models in the Beocord 5000 range:the three head type 4705 was replaced in 1977 with the twin head 4715/4716 models.

What you need to know is that these were the only cassette deck with a B&O designed mechanism. It was designed to be to cassette decks what the Beogram 4000 was to record players. From a technical point of view, it was way ahead of its time.

However it was stupendously complicated and this hit reliability hard. The three head version hardly ever worked fully and the later two head was only a little better. Gorgeous to look at and packed with features, it will break your heart! B&O replaced this with the Beocord 8000, which had a bought in tape transport….

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BeoCord 1100 (1975)

Bang & Olufsen BeoCord 1100

The fact that the Beocord 1100 was equipped with Dolby B Noise Reduction system immediately placed it among the market’s better cassette decks (catalogue 1977 / 78).

It had all the facilities you needed for recording compact cassettes and replaying them through an existing amplifier system. The combined record/playback head was made of Super Permalloy, an extremely durable material which ensured a long useful lifetime and had excellent magnetic properties. Other refinements included an electronic auto stop at end-of-tape and a switch for selecting between chromium dioxide and normal (ferric oxide) tapes.

The setting of correct recording levels was by way of individual controls used in conjunction with VU meters for left and right channels. Beocord 1101 was technically identical to Beocord 1100 but had a different exterior finish.

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BeoCord 1101 (1975)

Bang & Olufsen BeoCord 1101

The fact that the Beocord 1100 was equipped with Dolby B Noise Reduction system immediately placed it among the market’s better cassette decks (catalogue 1977 / 78).
It had all the facilities you needed for recording compact cassettes and replaying them through an existing amplifier system. The combined record/playback head was made of Super Permalloy, an extremely durable material which ensured a long useful lifetime and had excellent magnetic properties. Other refinements included an electronic auto stop at end-of-tape and a switch for selecting between chromium dioxide and normal (ferric oxide) tapes.

The setting of correct recording levels was by way of individual controls used in conjunction with VU meters for left and right channels. Beocord 1101 was technically identical to Beocord 1100 but had a different exterior finish.

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BeoVox 1001

Bang & Olufsen BeoVox 1001

The Beovox 1001 was a very similar loudspeaker to the Beovox 1200 (Beosystem 1200 version), but to match the new black finish of the Beomaster 1001 the metal grille was made black.

Sadly, the designers did not take the opportunity to fit a dome tweeter (as fitted to every other Beovox loudspeaker of the period), so the original (and outmoded) 2.5” cone type remained. As the Beomaster 1001 offered the facility of Ambiophonic stereo, 4 Beovox 1001s could be connected, and the model was also suggested for use with the Beogram 1500-1 record player.

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BeoCenter 3500

Bang & Olufsen BeoCenter 3500

A combination system with the quality and specifications of “separates”

Beocenter 3500 was built upon the Beomaster 3000 and combined a top quality FM tuner, an automatic record-player and a powerful stereo amplifier. The tuner had six pre-set stations for instant selection, plus a large manual tuning scale. There was an illuminated tuning indicator and a signal-strength meter to assist easy, accurate tuning. The powerful amplifier produced 2 x 40 watts RMS of high-fidelity output and was equipped with switchable filters.

There was a comprehensive range of connection facilities including sockets for two pairs of loudspeakers, headphones and a tape recorder with monitoring. The record-layer was fully automatic with one master-control for operating all functions. You only have to select the control position applicable to the size of the record, and touch a button. Beocenter 3500 was an ideal, simple way of enjoying high quality sound from records and radio. It was fitted with a robust hinged dust cover which protects records during play.

Features:

In the high-fidelity amplifier section, emphasis was placed on specifications, frequency correction and connection facilities. The LOUDNESS feature permitted switching between an objective or a subjective linear reproduction and the LOW and I-II filter controls gave a sharper regulation of frequencies in addition to the normal bass and treble controls. The LOW filter helped reduce rumble resulting from poor records. The EH filter reduced hiss. There were sockets and push buttons for two pairs of loudspeakers. The headphone socket was on the receiver’s front. The tape connection facilitated AB monitoring. All input signals could be adjusted at the receiver’s base to give equal sound intensity on all programme sources. The FM section had six pre-set FM station selectors.

A light indicator assisted accurate tuning and an illuminated meter registered the signal strength of a station. The FM section was extremely sensitive (better than 1.4 uV I.E.C.) and harmonic distortion was a mere 0.4%. Field effect transistors, ceramic filters and integrated circuits were used. The built-in record-player was perfectly matched to the rest of the unit, from a specification point of view. The fitted pickup cartridge, the SP 10A (later SP 12A) had a spherical naked diamond and a stylus pressure of 1.2 grams. Frequency range was 20 – 25000 Hz ± 3 dB and distortion was lower than 1%. Wow and flutter was less than 0.09% and rumble was better than 60 dB.

The record player section was easy to operate: you simply selected the size of the record you intend to play – 7″, 10″ or 12″ – and press a button. The record-player automatically selected the correct speed – 33 or 45 rpm – and lowered the pick-up into the first groove. When the record ended, the pick-up arm returned to its resting place and the turntable switched off. The turntable and pick-up arm had a pendulum suspension which made the record-player section insensitive to vibrations. Deep furrows in the turntable made it easy to pick up records. A stroboscope and a spindle adaptor for centreless records was provided. Beocenter 3500 was fitted with a hinged dust lid which was easily removed by a sliding action.

Beocenter 3500 had an extra Phono input. This was a ‘hang over’ from the Beomasters of the time which allowed two Beograms to be connected to the music centre. However, Phono 2 needed an RIAA pre-amplifier as it required a line level input. This feature became ‘Tape 2’ in later models.

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BeoCenter 4600

Bang & Olufsen BeoCenter 4600

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.

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BeoVox S75

Bang & Olufsen Beovox S75

The S75 was a four way speaker designed for stand mounting and was a suitable match for any of the receivers offered at the time. It could be regarded as the bigger brother of the fabled S45.2 and replaced the very similar S60 in the speaker range.

The cross over was changed along with a redesign of the cabinet. The result was a speaker with more bass emphasis than the S60 but still with a soaring top end. Criticism could be levelled that the bass was at times slightly overblown, but for rock music, it hit the spot.

The extra size also emphasised the cabinet makers’ skill with the rosewood model in particular often showing a wonderful selection of flame veneer.

Although these speakers lack the accuracy of the S45.2, many will find the extra bass an attraction and will choose these in front of their fabled brother.

Beovox Uni-Phase S75

Pressure chamber speaker with linear phase sound reproduction and wide frequency range: 36 – 20000 Hz. Was suitable for placement in a shelving system but also available with aluminium pedestal for those who prefer a free-standing model. Speaker units included a 25cm woofer, a special 12,5cm Phase Link unit, a 5cm mid-range dome and a 2,5 dome tweeter. Volume was 40 litres; weight 11kg