A recent comment on another forum was that most LP12's 'breathe' i.e. if you look closely at the edge of the armboard during play you will see it move up and down slightly. The argument was in effect that this was a flaw and that the Linn could be easily beaten on pitch stability.
On checking my turntable I noticed no such movemement and put it down to the fact that it is perfectly level and sitting on a level platform and hence the suspension was not trying to set it's own level.
However it has got me wondering whether such 'breathing' movements are the norm or indeed if it is fine tuned out as part of the setup process by those that know what they are doing?
Mike
Hi,
no! The LP 12 should not move noticeable while playing a record.
Other wise it is a failure of the platter. Some of the latest LP 12 have this problem.
cheers
Try to put a toothpick or a matchstick on the plinth horizontally at the right side of the plinth. Then point a lightsource at a small angle from the right side of the TT. Then you will see a shadow of the toothpick/matchstick on the armboard. This shadow will act as a magnifier and if there is any vertical movement during rotation you should see it.
Without this trick I can not see any movement on my LP12 but I can easily see a vertical movement with the help of the shadow.
The reason for the movement is IMO because the mass distribution of the outer platter is not perfect.
Hallgrim
A recent comment on another forum was that most LP12's 'breathe' i.e. if you look closely at the edge of the armboard during play you will see it move up and down slightly. The argument was in effect that this was a flaw and that the Linn could be easily beaten on pitch stability.
On checking my turntable I noticed no such movemement and put it down to the fact that it is perfectly level and sitting on a level platform and hence the suspension was not trying to set it's own level.
However it has got me wondering whether such 'breathing' movements are the norm or indeed if it is fine tuned out as part of the setup process by those that know what they are doing?
Mike
Leave things as they are.
Up/down movement of the armboard indicates a platter that is out of balance. This subject has been covered in depth on the forum before. I don't know how to insert a link but if you look at page 4 of the LP12 section "Bouncing/unbalanced platter on the LP12" all will be revealed.
A balanced platter sounds HUGELY better than an unbalanced one.
It sounds to me as though your platter is perfect.
Try to put a toothpick or a matchstick on the plinth horizontally at the right side of the plinth. Then point a lightsource at a small angle from the right side of the TT. Then you will see a shadow of the toothpick/matchstick on the armboard. This shadow will act as a magnifier and if there is any vertical movement during rotation you should see it.
....
Hallgrim
Thanks Hallgrim,
this is a very suitable workarround! Just tried and I'm a very luck LP 12 owner: NO MOVEMENT AT ALL!!! 
thanks again & cheers