Beomaster 3000 family

(1970-1972) FM stereo receiver, 2x40W

Type number: 2402

The Beomaster 3000 was an important and successful model for B&O. It was the first of a new generation of receivers that combined the quality of the very best Hi-Fi components with the easy of use of a normal radio. Launched to fit into the range between the Beomaster 1000 and the Beolab 5000 system, the Beomaster 3000 also defined a new division in the B&O range, the “High Fidelity” line, which at the time included the Beomaster 3000 and the Beolab 5000 system. “High Fidelity” models included the best technology available to ensure maximum performance, and were also usually very powerful. The less exacting models, such as the Beomaster 900, 1000 and 1200, were classified as the “Audio” range, and tended to be cheaper and less powerful. Text copyright © Beocentral. Unauthorised reproduction prohibited.

The Beomaster 3000 was a 40W FM receiver of compact proportions and modern, elegant appearance. Sliding controls, like those of the Beolab 5000, were used to good effect and these were supplemented by a row of neat lever switches machined from aluminium (an improvement over the flimsy plastic buttons fitted to the Beolab components!). These switches controlled all the functions of the Beomaster 3000, and were grouped sensibly and logically to simplify operation. Functions included switches for two pairs of loudspeakers, hi and lo filters, a compensated loudness control, stereo channel switches (that if operated together could be used to select mono operation), 5 FM radio preset stations and selectors for a tape recorder (which could be a three head type, such as the Beocord 1800, in which case monitoring was possible) and two record players, one with a magnetic pickup and one with either a ceramic pickup or a Beogram fitted with a pre-amplifier. Text copyright © Beocentral. Unauthorised reproduction prohibited.

The FM preset radio stations were set by a row of tiny thumbwheels below the main tuning scale. These could be difficult to adjust, but a really effective AFC system was fitted , along with a dual-light tuning indicator and signal strength meter, so in practice good reception could usually be secured, even by an inexperienced operator. The amplifier section, noted for its neutral, uncoloured sound, was considered really powerful at the time and could drive two pairs of large loudspeakers easily. Unlike many early solid-state designs, the potentially fragile output transistors were well protected by an elaborate circuit called an “electronic fuse”. As a result, reliability was excellent. As with some of the other models, loudspeaker inputs were provided too. These were switched to whichever loudspeakers were switched “off” using the switches on the front panel. Text copyright © Beocentral. Unauthorised reproduction prohibited.

Of course to make the best use of the quality of reproduction available it would have been best to connect B&O equipment to function as the auxiliary sources, provisions were made to connect whatever the owner could afford. To this end, both DIN and RCA type input sockets were fitted. Level controls, made accessible through holes in the underside, were provided to avoid large volume changes between sources. In order to aid their accurate adjustment, a switch marked “test” on the rear panel could be used. This configured the loudspeakers to sound only the “difference” between the two channels. Thus, if a mono tape or record was played on the source to be adjusted, the level controls could then be set for minimum output, corresponding to equal gain on both channels. Text copyright © Beocentral. Unauthorised reproduction prohibited.

The Beomaster 3000 and its derivatives remained in the catalogue for many years. The last surviving version was the Beocenter 3500, which was in most areas identical to the Beomaster 3000 and offered identical performance. Text copyright © Beocentral. Unauthorised reproduction prohibited.

(1973-1977) FM stereo receiver, 2x40W

Type number: 2402

An updated version of the Beomaster 3000. The two models were visually indistinguishable except for the model number, but the Beomaster 3000-2 contained a few minor technical improvements. The effect of these was not obvious, though the change did reflect well the company’s desire to offer the very best possible product at any point in time. Text copyright © Beocentral. Unauthorised reproduction prohibited.

(1973-1977) FM stereo receiver, 2x60W

Type numbers: 2406, 2408

The Beomaster 4000 was positioned in the range above the Beomaster 3000-2. It offered, in addition to the 3000-2’s many facilities, built-in ambiophonic stereo switching, connections for a second tape recorder and most importantly, more power. Rated at 60W, the Beomaster 4000 was as powerful as the previous Beolab 5000 system. Advances in electronics and manufacturing technique had allowed the Beolab 5000’s capabilities to be included in a smaller, simpler, more elegant package, and so once again an amplifier with what was at the time a massive power output featured in the B&O range. Text copyright © Beocentral. Unauthorised reproduction prohibited.

In contrast to the Beomaster 3000-2, the fascia of the Beomaster 4000 was finished in black. The sliding controls also had black trims, and green hairline markers, matching those of the Beocord 2200, the recommended cassette deck for the model. To allow for extra cooling for the hard working power stages at the rear, a metal grille, in matching black anodised aluminium the fascia, was fitted across the rear of the cabinet. Apart from these cabinet details, visual changes were few and tricky to spot. Those with sharp eyes would notice that the switch for the second pair of loudspeakers was marked slightly differently, and that the L-mono-R switches had been replaced with a mono switch and top-cut filter for the rear ambiophonic loudspeakers. The only other difference on the front panel was that the “phono 2” switch was now labelled “tape 2”. This connection was more suited to a cassette deck than an open-reel machine as it was not included in a monitoring loop. Only small changes were required to the circuit to make this change, the phono 2 input of the Beomaster 3000 and 3000-2 was “line” level anyway (for a ceramic pickup or a Beogram with a pre-amplifier), so all that was needed was to add connection to the socket to provide an output for recording. Of course the above-mentioned types of record player could still be connected to “tape 2”. At the rear, a small switch was fitted to switch between stereo and ambiophonic reproduction on “speakers 2”, and the duplicated RCA connections associated with the DIN sockets had been removed. Text copyright © Beocentral. Unauthorised reproduction prohibited.

While most of the basic assemblies inside the Beomaster 4000 were much as those in the Beomaster 3000-2, including much of the power amplifier. The use of Darlington output transistors and an increased supply voltage were the main changes that yielded an increase in output power. Some versions had extra variable resistors associated with the output transistors which had to be carefully adjusted to obtain the best performance and stability. Text copyright © Beocentral. Unauthorised reproduction prohibited.

The Beomaster 4000 was the centrepiece of a sophisticated Hi-Fi system, which also comprised Beogram 4000, Beocord 2200, Beovox 5700 and if desired, Beovox 2702 as the extra loudspeakers for ambiophonic reproduction. Other expensive Beomaster models, such as the Beomaster 6000 4 channel, overshadowed the 4000 in its later life, but the concept was revived in 1978 in the form of the Beomaster 4400 and 4401. Text copyright © Beocentral. Unauthorised reproduction prohibited.

(1977-1980) FM stereo receiver, 2x75W, Ambiophonic mode

Type numbers: 2417, 2419

The final model in this long running series, replacing the Beomaster 4000. From the outside, the Beomaster 4400 was set apart from previous models by its angled control panel, though the controls were largely in their normal positions. The facia finish returned to natural aluminium, and aside from detail changes in the functions of some of the switches, it would have been easy to confuse this new top line model for the Beomaster 3000 of 1970. Inside though, it was mostly new. The output power had been raised to 75 watts, at the time the most powerful Beomaster yet made, and the first to exceed the power of the Beolab 5000 system of 1968 (the Beolab 5000 amplifier was rated at 60 watts). This was done using a new technique employing 4 output transistors in each output stage (8 in total), in a novel series circuit. The increased power brought with it a need for better protection, so a latching relay was also included to cut the power if anything went wrong, thus avoiding expensive damage to the loudspeakers. In order to allow the power to be used to its best advantage, an overload lamp was added, taking the place of the stereo indicator of the Beomaster 3000 (the stereo indicator of the 4400 was a small LED lamp over the tuning indicator). This indicated when the output was becoming distorted, and though the amplifier could be used with the lamp either flickering or permanently on without damage, the user knew that the sound quality may have been reduced by the onset of distortion. The device was sensitive, and began to indicate before the sound was audibly distorted. At this level though, it would also be very loud, and the instruction manual noted that “the volume control should be used with discretion”. The Ambiphonic system of simulated 4 channel stereo was carried over from the Beomaster 4000, though the filter for the rear channels was omitted. A switch on the rear panel reconfigured the Ambiphonic loudspeaker sockets to act as normal stereo connections, for use with a second pair of loudspeakers in another room. Another interesting addition to the amplifier section was the “linear” switch, which cut out the treble and bass controls, and disabled the loudness circuit. By removing these sections from the signal path, quality was slightly improved, and the user was assured that the amplifier would be “colouring” the signal as little as possible. Features such as this, the overload indicator and the unusual output stage circuitry would remain a part of the best Beomasters for many years, and were all included on Beomaster 8000, the most powerful and sophisticated one of all. Text copyright © Beocentral. Unauthorised reproduction prohibited.

The connections for two tape recorders were carried over from the Beomaster 4000. Again, Tape 1 was intended for open reel machines and included an off-tape monitoring loop. Tape 2 was suggested for a cassette recorder (such as the Beocord 1100), and did not offer monitoring facilities. It was possible to record from one to the other in either direction though. Text copyright © Beocentral. Unauthorised reproduction prohibited.

The external appearance of the radio section had altered little from the first Beomaster 3000, the only obvious change was that the scale now went right up to 108MHz. The five preset positions remained unchanged, and the little wheels were just as difficult to adjust! The tuning meter and balance lamps were also still there, but the inclusion of the overload lamp displaced the stereo indicator to a position just above the tuning meter (see above). The radio circuit though had changed a lot, and was far more sensitive than that of the Beomaster 3000. It made use of more and better integrated circuits, and could yield clean stereo performance from far weaker signals. Text copyright © Beocentral. Unauthorised reproduction prohibited.

Whilst there was no doubting the excellence of the engineering behind the Beomaster 4400, it enjoyed only limited success. By 1977, it still looked like a model from 7 years previously. 1977 also saw the launch of the Beomaster 1900, a much sleeker and slimmer model, with touch sensitive controls. The Beomaster 4400 would be the last of the Beomasters to be made in this style, and was replaced by the Beomaster 6000, which featured black glass and touch buttons in place of teak and slide controls. Text copyright © Beocentral. Unauthorised reproduction prohibited.

(1977-1980) FM stereo receiver, 2x75W, Ambiophonic mode

Type number: 2416

This model was in all technical respects identical to the Beomaster 4400, the only difference was that the fascia was finished in black. Text copyright © Beocentral. Unauthorised reproduction prohibited.