On my prior post, I would like to add that my assumption was that your Linn and its tonearm are not damaged, are lubricated properly and located in a good solid rack. In addition, I would pick 4-6 records that are good recordings with little or no compression to use as my reference. For example, reproductions from Three Blind Mice recordings from IMPEX is a good start (i.e. Isao Suzuki's Blow Up or the TBM 6-LP collection), Keth Jarrett's Koln Concert and Standards Vol 1 and 2, Willie Nelson's Stardust, Talking Heads Live 1980-1981, Patricia Barber's Cafe Blue will be my test foundation to evaluate articulation, harmonics, soundstage and dynamics.
Again, all the best in this journey, Basile