Bang and Olufsen Beogram 7000 CD Player. Black.
Bang and Olufsen Beogram 7000 CD Player. Black.
**Please note: The quoted price includes the Beomaster 7000 (Black) and Beolink 7000 remote with floor stand in superb condition
Great care was taken by Bang and Olufsen with the design of the CD 7000 player. The main objectives for the construction of CD7000 were mechanical stability, excellent sonic qualities and easy access to the myriad of CD functions via the Beolink 7000.
The loading mechanism, the clamp function and the suspension of the CD mechanism were all points that received special attention. The high quality of the mechanics was carried through to the electronic circuitry.
The CD tray is a solid affair, constructed from 4 mm thick aluminium. The conical recess for the CD is milled and diamond polished to close tolerances to prevent dust accumulation. The circular rubber profile protects the disc during loading and unloading, whilst the triangular cut-out facilitates unloading. To avoid static build-up, the tray is connected to ground, and to prevent 'ringing', a damping plate is placed at the innermost part of the tray, inside the cabinet.
The motorised movement of the CD tray is fast and gentle, instilling the justified feeling of mechanical excellence and reliability in the player. This movement is controlled by a microprocessor via an opto-coupler with a stable method utilizing two parallel chrome plated brass rail tubes, and precision roller bearings. The electronically governed transport is smooth, beginning the movement slowly then speeding up very quickly, decelerating when the disc approached the clamp. Furthermore, it secured against possible damage occurring from obstacles either in front of the tray or in between tray and cabinet.
As the tray approaches the clamp, the disc is gently lifted off the tray and clamped between the CD mechanism and a magnet. The magnet is placed on a bridge across the CD mechanism, and as it engages the disc, the magnet is lifted away from the bridge. While the disc is rotating, the magnet is not in contact with the cabinet, but only the disc and CD mechanism.
This assembly is effectively isolated from the casing to avoid external vibrations. A special suspension was designed, with 4 steel springs, encased in rubber. The springs ensured that the CD mechanism was fixed in the horizontal plane (i.e. across the disc), while a certain amount of movement was allowed in the vertical plane. Tests show that the servo system primarily counteracts movement in the vertical plane, and as the disc is fixed in the horizontal plane, the suspension remains a good compromise with regard to immunity from external vibrations. The inherent resonant frequency of the suspension is placed at 25 Hz to avoid tracking and focusing errors. These are more likely if the CD mechanism is subjected to vibrations around 100 Hz and upward. Furthermore, at this frequency, interference with the inherent resonance of the CD cabinet was also avoided.
The electronics within the CD 7000 were just as carefully conceived. Separate power supplies exist for the digital and analogue sections, and with a careful layout of the electronics, Bang & Olufsen achieved an excellent electronic specification.
The digital-to-analogue filtering received special attention.. Firstly, a standard digital filtering (4 x oversampling) was applied to filter away the sidebands below 176,4 kHz. The analogue filtering at 176,4 kHz is carried out by a modified order filter. To avoid remnants of the 176,4kHz sideband having an effect on the filtering, a special suction circuit cuts off frequencies above 156,4 kHz. The modified filter is known as a 'Bessel elliptical filter'. It has a very gentle filter characteristic and is not susceptible to ripple phenomena, phase distortion or ageing.
As with the other Beosystem 7000 sources, operation is via the Beolink 7000 with a full display readout of all functions. Special functions available include the spacing, where a pause of 4 seconds was added between tracks to facilitate track search on a tape recorded from CD 7000. Scanning allows for playback of the first 15 seconds of each track is useful for sequence programming.
When scanning a CD, tracks can either be selected (compiled) or omitted. When the last track has been scanned, playback of the programmed sequence commenced. Sequence programming can also be carried out independently of the scan function.
**Please note: The quoted price includes the Beomaster 7000 (Black) and Beolink 7000 remote with floor stand
Frequency range: 3 - 20,000 Hz +/- 0.3 dB
Signal-to-noise ratio: > 100 dB / 110 dB A-weighted
Dynamic range: > 96 dB
Harmonic distortion incl. noise: < 0.0025% at 0 dB;< 0.025% at -20 dB
Channel separation: > 101 dB
Channel difference: < 0.08 dB
Converter system: 2 x 16 bit, 4 x oversampling 176.4
Low pass filter: Digital + Bessel/elliptical analogueDamping: > 20,000 Hz > 50 dB
Phase error between L and R 0 degree at 20 - 20,000 Hz
Output analogue: 1.3 V RMS at 0 dB
Output, signal: For digital equipment
Power supply: 240 V.Power consumption: 23 W
Dimensions W x H x D: 42 x 7.5 x 32.5 cm
Weight: 6.3 kg