Ortofon Concorde Club MKII 70 Twin

I come from many years of NightClub E first series.I thought instead of buying a new set of styli for them, let's give it a shot and try the new Mk2's.Immediately when trying them for the first time I noticed a grainy harshness in the high frequencies,I would go so far as saying even distorsion.I actually read the same exact impressions in some comments of people that had the same experience and were so disappointed that ended up returning them.I thought ok, they might have to be burned in still and decided not to return them.I do not use them that often, but I have to say that they did settle more after some hours of use (probably they need quite some more), but I still feel that there is something not right...maybe manufacturing defect ? I thought I will ask my friend to make a comparison with his pair of used normal yellow MK2's (6 months old).Immediately it was evident that the overall volume was significantly higher on his pair and the highs were not sounding grainy.Compared to my older Nightclub E's these are definitely more detailed and revealing but the issue with the graininess is quite a disappointment.