The armboard and platter axes are fixed by the subchassis. If one is level and the other is not, then the subchassis, plinth or top plate is bent or the armboard/main bearing is not installed correctly. There's not much to go wrong here if all the parts are good and installed correctly. Make sure the grommets are properly seated. The top plate sags in the middle so this might give the impression of a downward slope from the middle to the front (but also the middle to the back). Good Luck!
Setup for Linn LP12?
I recently acquired a Linn LP12/Circus/trampolin and Ekos. In adjusting the 3 springs I can get the arm board centred, level with the plinth and moving vertically. However, the platter has a distinct slope from back to front. Is there another adjustment to level the platter or to adjust the position of the bearing well? With the weight of the Ekos toward the back of the arm board, I do not see how using only the springs, both the arm board and platter can be levelled. I would appreciate any advice from Linn owners.