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Tables That Feature Bearing Friction

I recently had the opportunity to audition the DPS turntable which, unlike most tables, has a certain amount of friction designed into the bearing. This, when paired with a high quality/high torque motor, is said to allow for greater speed stability--sort of like shifting to a lower gear when driving down a steep hill and allowing the engine to provide some breaking effect and thus greater vehicular stability. I am intrigued by this idea and was wondering what other people thought about this design approach. Are there other tables which use this bearing principal? One concern I have is that by introducing friction you may also be introducing noise. Comments?
dodgealum

Showing 2 responses by dougdeacon

dougdeacon
3,338 posts
 
Basis, Galibier, Teres, Redpoint, Mosin's Saskia, Garrard, probably many others. Chris Brady wrote an effective explanation of how a carefully chosen amount of steady-state drag (from the bearing, an eddy current brake or otherwise) can minimize the effect of variable drag events (i.e., stylus drag). Check the Teres website, it's on there somewhere. The concept is that if the motor is working against a high steady load, the proportional value of any stylus drag event is reduced. That makes it easier for the motor/coupling system to overcome. If a table shows the motor/coupling system little or no load, each stylus drag event is proportionately much greater and therefore more likely to be audible.

Having heard most of the tables mentioned above, my ears agree that the theory has merit, always depending on execution of course - as Dan said. It certainly works with Mosin's table, brilliantly.
dougdeacon
3,338 posts
 
Lew,
Chris Brady's Certus DD designs are said to implement this principle very thoroughly, as does his Verus rim drive, both due to the the motor design.

His belt drives used bearing design and choice of lubrication to achieve a similar effect (as do the similar designs from Galibier and Redpoint). Bearing noise on any of these is nonexistent in any system I've heard, including mine. Motor noise transmitted through the belt, while very low, is more audible than that.
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