Manufactured: 1974 - 1979
Designer: Subir Pramanik
Bang & Olufsen's (then) most accomplished pickup cartridge was fitted to Beogram 6000.
The MMC principle was adapted to track 4-channel records: both Quadradiscs and SQ. MMC 6000 would track both mono and stereo records with the utmost fidelity. It was designed for record-players with tangential arms. The stylus was the Pramanik diamond, named after its inventor: engineer S K Pramanik from Bang & Olufsen's Laboratories.
The diamond's radii were 7 um/2 x 50 um. It was a refinement of the elliptical shape, rather like the shape of the cutter-head, and enabled greater contact with the undulations of the record groove. The cantilever was made of berylium - a material which is harder yet lighter than popularly-used aluminium. Effective tip mass was 0.22 mg. Compliance was higher than 30x10-6 cm/dyne. Recommended- stylus pressure was 1g. The total frequency range was 20-45.000 Hz.
In the audible range: 20-15.000 Hz there is less than 1.5 dB variation and in the inaudible range 20,000-45,000 Hz where the carrier frequencies lie, the pick-up fulfils RCA/JVC's specifications for a Class A discrete 4-channel pick-up cartridge. Each cartridge is an integrated, individually calibrated unit. The stylus unit is not separately replaceable since it is part of the integrated unit. An individual frequency response curve traced on a Bruel & Kjaer level recorder and a complete Calibration Card were enclosed with every MMC 6000 sold.
MMC6000 Product Specifications
Radius of curvature CD-4 quadro
Frequency range 20 - 15000 Hz+/- 1,5dB 20 - 45000 Hz (CD4)
Channel separation 1000Hz >25dB
40 - 10000Hz >20dB
Channel difference <1,5dB
Recommended stylus pressure 1g
Compliance 30 x 10(-6)cm/dyne
Effective tip mass 0,22mg
Output mV/cm/sec. 0,6mV/47kOhms
Created: 14th January 2007
Modified: 17th May 2007
Q.12 Black plastic blank, but a change to red illuminations signifies presence of optional quartet.