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?
128x128dodgealum
Dear Kirkus, Lewm, (Teres ??) and Dan_ed, if we all join forces in this discussion I am positive that it will become a really worthwhile discurse.
Of course - stylus drag is rather a very variable force and can not really be called a "constant".
So - how do we proceed?? Do we carry on in this thread or is one of you starting another focussing on the turntable design in general, maybe with stylus drag and its influence on stability as a sidematter? Any suggestions? I am happy to participate in a real good discussion when we focus on technical aspects.
What I wrote was that any effect of stylus drag on speed will in part be a function of the distance of the stylus from the spindle (not "distance from the stylus"). I was referring to the mechanical advantage gained by applying a force some distance from the center of rotation vs near to the center of rotation. Kirkus got it right.
Dear friends: I'm not on the TT design ( tonearm/cartridge is my priority. ) but this discussion could help to everyone in some way or other, at least to understand what is happening.

Some of you " speak " about specs and IMHO this subject could be very controversial for say the least.
Many of the " standard " specs/measures on audio items ( any ) can't explain per-se why we hear/heard what we hear/heard.
My opinion on the subject is try to define what/where/how to measure and its relationship with what we hear/heard or our targets about. IMHO not an easy task: whom will fix/decide those " true/new spec standards "?. Anyway a good " exercise ".

A second subject: stylus drag. During our tonearm/cartridge research/design I made several tests and still doing ( for different reasons that TT design. ), one of them was this:

I choose seven different cartridges ( different stylus/compliance/MM-MC design, VTF, etc. ) and five different LP's.
The test was over the same TT and same tonearm ( at the same time. ) where the " only " variable was the cartridge ( well more than one variable due that each cartridge has different parameters. ).
The test was a " home test " not a strict controled and scientific one but interesting.

What we want to measure was how the stylus drag ( well the tonearm/cartridge. ) could change with different cartridge in different LP in different velocity recorded tracks that I choose.

What we do?: we put " that " cartridge in the tracks ( each one at the same time ) I choose ( running the TT at 33 rpm. ) and suddenly switching-off the TT and measure how many seconds take the platter to stop. I choose three tracks on one side in the LP: one at the outer of the LP one at the middle and one at the inner of the LP.
The tools I used was a cronometer, eyes and very fast " brain reaction ".

Not an easy test, I have to train for several hours ( two days ) till I " show " good " constant " response ".

This test show us that that stylus drag " exist ", that its behavior is cartridge/stylus/VTF/position on the LP dependent, that is different on different tonearms and TTs, that a heavy platter ( 20 kg. ) in rotation has an influence on that stylus drag when you swtich-off, etc, etc .

I know that maybe this almost " hobby-test " does not help on the TT discussion due that the TT was/is switch-off and that was not made it in a scientific/tools way but the test opened my " eyes " for our self tonearm/cartridge design.

It is not to easy the desing/research on " mechanical " devices ( like tonearm/TT and the like . ) specially the tests of those devices because it is not only a subject to have the know-how what/which/where/how but to have the precise scientific tools to do it: we need a laboratory and we need a lot lot of money to have that laboratory.
This issue is/was one of the reasons that bring us ( on the tonearm design ) to find where to do it, finally we meet our friend at the University and even here is not easy because is something " new " where the " scientists " does not have many experiences: it is an easy task for them nothing difficult but " new ".

Like always, I say every single day is a learning one to anyone in different areas/topics on our day by day life. There are more knowledge to discover to experience that our self ( each one ) know-how.

Regards and enjoy the music.
Raul.
Hi Raul . . . were you able to get any comparisons of stylus drag between a modulated and an unmodulated groove? I think that's one of the central points of most of the discussion of stylus drag.
Dear Dertonarm: +++++ " If the NASA had handled the Apollo - Mission that way, man would have never set his foot on the moon. " +++++

there is no single doubt about, everything must be " perfect " for that " job ", you can't have/make mistakes or " guesswork ".. science is the law.

In the analog audio " stage " science is still the law but the analog " world " is an imperfect one ( everywhere in the analog chain. ) that tolerate some " guesswork " in order to achve desirable targets.

There is not much research on the subject and not because there are not good audio item designers ( there are ) but mainly because there are too many " conformist and non know-how " customers: why a designer has to worry on a " perfect " design when no one is asking for? when almost no one cares about?

Almost all the analog audio item designs are more a commercial subject ( $$$$, in some ways it has to be, between other things. ) that a top quality performance to bring a top satisfaction to the customer, even the very high price items.

Where are the customers? where are we? how can the analog audio market really grow-up if we are " satisfied " with what we have? we are satisfied with the same/similar audio item designs of " 50-100 " years ago ( many times lesser designs. ), where we leave the " emotion " to explore to discover to think in a " new " way?: almost no one cares about and IMHO that's why: ++++ " I have yet to see a turntable design done right. " +++++ ( or almost any other audio item. ) we are " down " here " ( in a deep hole ) and not because there are not good " professional " designers ( there are: several. ) or people with the enough knoledge to do it.

This is not the first time that I point out these subjects and if we continue to pay for " mediocrity " that's will be exactly what we will have: " mediocrity ", IMHO I think that we need a customer " revolution ", we need to shake all those talent people out there for they give us what today we deserve, we are " the one " to make things change for the better we need to be active part of the changes.

Regards and enjoy the music.
Raul.