B&O made the switch of sides in all of their turntables  in the mid 1980’s. They still perform the same record detection function. They became wider to display the speed while the cartridge carrier became narrower to support the smaller cartridges. The older service manuals for the 400x series provide the most detail on the tracking system.

Mark-sf wrote: B&O made the switch of sides in all of their turntables  in the mid 1980’s. They still perform the same record detection function. They became wider to display the speed while the cartridge carrier became narrower to support the smaller cartridges. The older service manuals for the 400x series provide the most detail on the tracking system. --- That's not quite right; Earlier Beogram tangentials use the second arm for record detection, and the arm contains an optical sensor system (light, lens etc.). In order to do this the sensor arm needed to be "in front" of (to the left of) the tonearm. Beogram 5500 and all other type 59xx decks have the extra arm to the right of the tonearm. This second arm has no sensor and performs no function apart from carrying the speed indicator lights at its outer end.  In these decks records are detected by weight. Martin

Thanks both - very interesting. I never realised that the second arm on the Beogram 5500 was there almost just "for show" !