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Should the platter and plinth be level?

Greetings all -

I've always made sure the plinth on my Rega P5 is level using a carpenters "bulls-eye" level. On a whim the other day I popped the level up onto to the platter and was amazed that it did not show it to be level. When I move it down to the plinth - it's showing level.

Don't misunderstand me - it's not a dramatic amount and if I eye-ball the platter and subplatter in relation to the plinth it all looks to be fairly level.

Should I be concerned that the platter is not rotating exactly level to the plinth? Should I adjust everything so that the platter is level and not worry about the plinth being level? I've checked speed, etc. - and everything's working smoothly without any problems so I suppose I shouldn't be worried about it but can't help thinking it's a bit odd.

Any input would be appreciated - I'd also REALLY appreciate anyone owning a P5 or P25 if they wouldn't mind checking to see if the same anomoly exists on their tables - maybe it's just the way it's designed and assembled.
slate1
slate1 OP
82 posts
 
Okay - the more I'm thinking about this, the less this is making sense. Adjusting the pitch of the platter by changing the base that it's sitting on isn't going to do anything.

The ONLY element I have control over here is plinth. No matter how I adjust it, the relationship between the tonearm and the platter is going to remain the same because they are both mounted to the plinth. Adjusting the plinth out of level so the platter is level isn't going to change that.

The degree of error here isnt much and it's not in the plane that the tonearm moves across the record in - it's parallell to the tonearm tube. In other words, it's not like the needle is tracking "uphill" or "downhill" - hope that makes sense!

The more I think about it, the only thing this could potentially slightly affect would be VTA and even that would be negligible here especially since I'm using the Rega Exact cartridge.

This is all very interesting, especially since there's another Rega owner with the same issue. I'm beginning to wonder if it's another one of Rega's unusual design elements; although I can't imagine why they would do this. If anyone else has a Rega table and is willing to check - I'd be curious to see if they're all like this!
raquel
841 posts
 
I have a Rega Planar 3 and a VPI Aries. With both tables, the plinth sits on a slightly different plane than the platter.

The only thing you should be concerned with is making sure the platter is level, as it is crucial that the stylus encounters a level surface. Put a good level on the platter with the mat removed. For the Rega, I used Post-Its, which are perfect for allowing you to get the platter level. Once I have the table leveled, I pull the Post-Its and blacken them out with a magic marker so they do not stand out. With the Aries, the feet adjust for leveling.

Hope this helps.
dan_ed
2,451 posts
 
Slate1,

Don't worry so much about the tonearm/platter angle. What is important is the angle of the stylus to the record. That is why we have all of these adjustments, VTA, azimuth, overhang, etc. Get the platter level then adjust whatever you need to in order to get the stylus angle correct in relation to the now level record groove.
sidssp
1,077 posts
 
Slate,

The RB-700 is a bearing arm, which requires a leveled pinch (actually the arm board). Otherwise, the arm will put more pressure towards the lower side.

On the other hand, a unipivoted arm (i.e. VPI JMW) is self-leveled which requires a leveled platter to maintain correct angular relationship with the record.
dr_balance
16 posts
 
My J.A michell Tecnodec does also the same thing. The platter is level but the base is not. I don't let it bother me. The small difference is nothing and can be compensated through tonearm adjustment like DAN_ED suggested above.
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