Beolab 5000

The Beolab 5000 was the amplifier part of the top of the range Beolab 5000 system. The system as a whole aimed to provide the very best possible professional standard performance and in line with this the Beolab 5000 was an amplifier of quite exceptional quality, in both technical and aesthetic terms. It would have also been considered as very powerful; there were very few (if any) amplifiers suitable for domestic use that could match it. Text copyright © Beocentral. Unauthorised reproduction prohibited.

The styling of the cabinet matched that of the Beomaster 5000 tuner. The same high quality materials were used and the dimensions were identical. A mains outlet socket was provided on the rear panel to connect the tuner to. A record player, fitted with either a conventional pickup or a B&O magnetic one, could also be connected, along with a tape recorder, a stereo microphone (for which shielded transformers were included in the circuit) and an auxiliary line source. A line output was also available, for the connection of a high quality 3 head tape recorder (such as the Beocord 2000 De Luxe) or an additional power amplifier. All the sockets were mounted underneath, which along with the not inconsiderable weight of the cabinet made connecting up difficult. All the sockets were of the DIN type, though the inputs were duplicated with RCA type sockets for use with foreign equipment. Text copyright © Beocentral. Unauthorised reproduction prohibited.

Two pairs of loudspeakers, controlled by two switches on the front, could be used. There was also a “centre” loudspeaker output which combined both channels, or could be used on its own. When used as a mono amplifier, 120W of power was available. The reason that this was possible was that the two channels operated in phase opposition. This was done by including a unity-gain phase inverter in one of the power amplifiers. Correct phasing was then restored by simply reversing the wiring to the loudspeaker sockets of that channel. Not only did this allow the Beolab 5000 to be easily used as a really powerful mono amplifier, it also improved the quality of stereo reproduction by evening out the loading on the power supply. The only downside to this arrangement was that a headphone socket could not be easily included, though the accessory “stereo spread unit” included one by the use of a transformer. The power supply section of the Beolab 5000 was also unusual because it provided a number of fully stabilised voltages for the various sections of the amplifier, including the power output stages. Such was the requirement for power for this latter function that two large transistors had to be used in parallel. Text copyright © Beocentral. Unauthorised reproduction prohibited.

A striking feature of the front panel was the use of sliding controls for volume, bass, treble and balance. Though this type of control would become familiar, on B&O equipment especially, it had not been seen before on domestic equipment. The very best was made of the styling possibilities that sliding controls allowed, and the fascia looked sleek and uncluttered. The use of the best quality parts and materials ensured these new controls operated perfectly smoothly. Text copyright © Beocentral. Unauthorised reproduction prohibited.

Despite the considerable development work that must have gone into it, the Beolab 5000 did not remain in production for very long. Improvements in components and circuit technique soon lead to smaller and easier to produce alternatives that offered the domestic user a comparable level of performance. The Beomaster 3000 represents a good example, and could be considered as a combined and rationalised version of the Beomaster 5000/Beolab 5000 combination. Later on the Beomaster 4000 would match the power of Beolab 5000 too, and the Beomaster 4400 would exceed it. The Beolab 5000 was not replaced in the range, as B&O ceased to offer separate amplifiers in their top-line range in favour of receivers (the later Beolab 1700 amplifier was not intended to replace Beolab 5000). Text copyright © Beocentral. Unauthorised reproduction prohibited.