Tables That Feature Bearing Friction

Hey Doug,

Call me Win. I'm trying to outlive the "mosin" moniker, but without much luck. ;)

Anyway, Chris did give a great explanation, and there are various implementations of it. Even sheer mass at the platter can help when the bearing arrangement is designed with braking in mind, but there are other implementations. Properly used, the motor itself can go a long way to controlling the spin. Also, Garrard (as you already know) used a grease bearing very effectively as a dynamic brake. The list goes on, but the most important thing is to make sure the turntable has no runaway effect, or that it is not bogged down anytime during its operation. Free spin equals loss of control, in my opinion.

Best,
Win

So I see that there are a number of tables that exploit this design principle in one way or another. Can anyone comment on the issue of bearing noise? Also, most of these tables are large and heavy. I'm using a wall mount shelf and therefore require a table that doesn't weigh a ton. Any suggestions as to models I should explore?

Free spin equals loss of control, in my opinion.

That's the best way to sum it up!

Dodgealum, there is no noise issue. Because a bearing is designed with some drag does not mean that it is being created by allowing things to rub together.

For the 'table designer this is much like matching a load with an amp. The motor will be able to control things much better if it is doing work against the load. This is what the bearing drag is for.

From a physics perspective, using the bearing drag to introduce a well defined load for the motor is certainly “sound” as nicely explained by Dougdeacon and others above.

The DPS differs from some of the other tables mentioned above: the bearing friction is significantly higher than on the other implementations since the DPS uses a light platter and doesn't have the benefit of the inertia of some of the above heavy mass tables. The reason behind the high friction is that, in comparison, any friction introduced by the needle (needle drag) is neglible. From my own experience, the DPS is one of the few tables with a light platter that does have any of the associated speed variations and in many ways sounds like a high mass design (of course the base is fairly high-mass anyway as it contains two layers of lead).

I have not noticed any detrimental effects for the DPS, especially not added noise. Several friends have commented that the DPS is in fact easily one of the quietest tables in our group with the blackest background (comparing to TW Raven AC, Platine Verdier, VPI Scoutmaster, Michell Gyro, etc.).

The DPS is IMO one of the most well designed and thought out tables out there. Everything is extremely carefully matched and optimized; e.g. Willi tried several different platter thickness and weight to optimally match the “loading” of the motor. If you are looking for a table with a slightly more compact form factor the DPS should be on your list. On the downside the design is not for someone who likes tweaking - the top base has to be replaced for a tonearm and it already comes with all the isolation and platforms you may ever need.

I don't know of any direct-drive tables that deliberately use this strategy, except possibly in their electronics. Can anyone think of any?