Our unique bearing just got better : "the true single point"
Our turntable bearing has always been unique because its point of contact does not move laterally. This is because it is held captive in a specially shaped sapphire jewel. Due to its inverted design we only use a single bush to prevent rocking, rather than the usual two or full sleeve. Both these features reduce bearing noise and in essence this remains unchanged.
The lower bush is manufactured from sintered bronze, a porous structure that is impregnated with special oil during manufacture. The same material is found in other appliances, from electric motors to high-speed drills. Its best to think of this material as a metal sponge, riddled throughout with fine capillaries, which during manufacture are filled with special oil.
As the bearing material rotates, the oil is released to the surface producing a film of lubrication between the fixed shaft and the bush. As the bush glides over the shaft, localised oil pressure is built up in front of the revolving surface and effectively it begins to aqua-plane, like a car does in heavy rain. This effect separates the moving parts, massively reducing noise compared with non-lubricated bearings, which are in full contact with rubbing surfaces.
As the bearing bush lifts away from the spindle there needs to be a gap, or 'running clearance' for it to rotate. Too tight and it will be forced to the other side of the bush and start rubbing, too loose and the bearing and platter will rock.
The two pictures opposite show our old and new style of bearing material, the new one the right. As can be seen from the picture the capillaries are much larger and visible compared to the older material. Greater volumes of lubrication at the surface has allowed us to increase the clearance gap further reducing noise, lowering the drag effect to the motor drive but maintaining bearing pressure and stability.
Standard on all our turntables and available as an upgrade on all previous models.