Be aware that changing to another cartridge is not that easy as it seems with this tonearm.
The cartridge must be very slim at the rear end, otherwise it will come in conflict with the contact pins coming out of the tonearm tube, those pins where the cartridge leads are fitted to.
Forget Ortofon 2M for example. They are to bulky. You won't be able to get it aligned properly. I tried to install a 2M red on my akito and that failed for this reason. Watching the photos of the LVX in the library here, i think the problem is the same, because of the space conditions in the headshell.
If you think the cartridge is the problem due to aging, get a replacement stylus for AT 95 E. This needle fits and works in the K9 body, although it looks funny. Set tracking force to 2 grams.
Before buying a costly cartridge, better ask a linn-experienced dealer what fits instead of failing in the end.
One record a day keeps the doctor away!