SP15
Manufactured: 1974 - 1974
Designer: Subir Pramanik
Colours: Silver
The SP15 was designed specifically for the Beogram 4000 turntable by a team led by Subir Pramanik. It retained the SP nomenclature (Stereo Pick up) but this led to problems as it was not compatible with other SP models and as a fairly high end cartridge, there were no lower numbers for the cheaper models to take. Therefore after one year it was renamed the MMC4000 (Moving Micro Cross).
The mechanism of action was unchanged from that of the SP range with a cross shaped armature set over 4 pole pins of a permanent magnet. Each pole was wound with a coil. At rest a small current passed from the pole, through the air gap and into the surrounding shield. Deflection of the armature would alter the amount of current in each pole. The poles were connected in such a way that the output voltage was doubled but any hum or distortion would cancel out.
This principle was used in all B&O stereo pickups from the SP1 to the MMC1 but with different degrees of miniaturisation.
The SP15 was however the first B&O stereo cartridge without a user replaceable stylus. To improve tolerances and because of the much smaller body, the SP15 had a sealed body. A a sop to the customer who would need to replace the whole cartridge, new cartridges were available at 50% of the new cost when a used one was exchanged. This was quite a bargain as new the SP15 cost nearly £40. This compared the the SP12 which was about £16 new.
The SP15 set good standards of reproduction - it was fitted with a naked elliptical diamond 5x17μ with a frequency response of better than +/- 2.5dB between 20 - 30,000 Hz. It tracked at only 1g.
The SP15 was only in the product range for a year before being renamed.
SP15 Product Specifications
Related Products
Related Articles
Created: 13th January 2007
Modified: 23rd August 2010
Author Notes:
Rare simply because not many were made as it was renamed MMC4000. Notable as the first of the B&O cartridges with a non replaceable stylus, the SP15 came with an agreement that when it needed replacing, a new cartridge was supplied at half price. This clause was dropped fairly quickly once it was renamed!
