Does the SIZE of the main bearing matters ?


The main bearing of a turntable is the housing for the hub or sub-platter which plays the major role in spinning our records. Therefore we shall not overlook the importance of this main bearing.

I notice most of the better decks I own come with main bearings of around 3/4''( ~18mm-20 mm) diameter . Here are a few examples:

Rega P5 TT, Planar 2/3 TT, Linn LP12TT, Thorens 150/160TT, Thorens 125TT......

In my opinion, to handle the rotating load efficiently,  the bearing must be sufficiently big (in thickness) in order to maintain rigidity. The bigger the diameter/thickness, the more rigid the bearing housing is. Moreover, bigger mass also helps to absorb some of the vibration and heat energy that is emanating from the bearing when the sub-platter is spinning.

I have a P1 TT which has a smaller bearing hub (12mm or ~ 1/2" in diameter). Its housing wall is thinner and fits the same sub-platter as my other Rega decks. It is also of lesser mass(~ 1/3 ) than that of its bigger brethren( P2 to P5).

Have nothing better to do, recently I thought of tweaking my P1 main bearing(12mm). With rigidity and higher mass in mind, I  designed and custom-made a hexagonal shape stainless steel main bearing sheath (19mm or 3/4") to be screwed on to the existing bearing. Of course you may say, just change this 12mm bearing to a new bigger bearing will do. But that would involve more tedious work like enlarging the mounting hole on the plinth which I don't wish to do.

If you are concerned that heavier glass/acrylic/delrin platters would be strenuous to the main bearing of your RP1/P1TT, this 3/4" heavy duty stainless steel bearing sheath probably would relieve you of your anxieties.

This simple tweak is easy to carry out for anyone without technical skill.

Bearing Sheath For P1/RP1
(BS1 - USD 8.00)
Side view





So improving the rigidity of the main bearing is another tweak to bring about sonic improvement!



Wes Anderson of Canada commented :


The "nut" does work well, you can definitely here a sound quality improvement over stock.                         




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