New platter bearing for Dual changers

And I do also often use a 1218, a 1219 and a 1019 and even a 1214 changer in additon to my several Dual Direct Drives (DDD). Just for the fun of using different turntables.

(Oh wait, didn't the meaning of that "DDD" abbrevation change after a while for something else about the way of audio reproduction?)

為什麼我們不就中性語言達成一致，例如中文？

VG

Benjamin

Die Magnetlagervariante habe ich mal getestet, aber da wurden wimre Mechanikteile auch angezogen, was die Automatik aus dem Tritt gebracht hat. Ich glaube, man musste dann etwas aus Kunststoff nachfertigen und ersetzen, damit das wieder läuft. Habe ich – wie so viele Dinge – nicht weiter verfolgt.

In meinem 1219 werkelt inzwischen ein nachgefertigter Lagerbock eines lieben Forenkollegen der das Lager nach unten verlagert (und wahrscheinlich durch einen anderen Typ ersetzt) hat. Die Automatikfunktion ist allerdings damit stillgelegt worden. Das ist mir allerdings egal, ich habe sie eh nie genutzt.

Das hatte ich damals gefilmt.

중국어는 중립적이지 않습니다. 더 나은 한국어.

Zitat von bobhund

man musste dann etwas aus Kunststoff nachfertigen und ersetzen

Messing geht auch, hab ich mal gemacht, damit funzt die Automatik.

Bei Kunststoff hätte ich Zweifel, ob das auf Dauer hält.

Das Problem bei mir war, dass ich keinen Magneten mit dem richtigen Innendurchmesser für oben gefunden habe.

LG, Jürgen

I think that every advice will be more guessing than knowledge what is the best possibility.

If Bruno from audiovault provides new bearings I think it likely that he tried them out before starting production. From that point of view I hope that he will have listened carefully if they aren't too noisy.

...and please tell us about your experiences! It would be interesting, to compare the bearing vom Audiovault with the cheap industrial bearings, offered at Ebay.

Hope you hear in tranquility and silence soon!

Axel

Zitat von Thorsten R

How could they are being silent whit that amount of balls?

Actually there some truth in this and the concave path used by the balls to roll in makes it worse because the finish needs to be a lot better than with the original flat bearing as it allows for more contact surface.Any precision bearing is obtained through intensive "burn in" use loaded in a period of a few months.With more balls you need higher loading to polish them and minimise rumble as well.It's easily seen in Neuman VMS80 where with a 20kg platter they chose half of a wheel bearing , undercuting the number of balls to just 6 out of 13 with a traditional nylon spacer and using once again a flat contact, actually only the sharp edge of a disc surface between the balls and the main platter .And the whole bearing is submersed in pressurized oil as it's called hidrodynamic bearing, being a little more complex than just a ball bearing as it does the power coupling through that same oil.Anyway, the Dual original ball bearings respect the original Neumann design principles for low rumble .

My advice to anyone using that kind of bearings is to use the thickest molybdenum grease and remove as many balls as needed as the original load for that bearing may be around one full ton , thus very far from the 3.2kg Dual platter.While you'll be able to hear the bearing with that grease much less rumble will be going through the mechanical coupling than expected.

I was a "beta Tester" for Bruno for his current "12XX" center bearing offerings.

I installed these bearings on my Dual 1229Q and my 1249.

Both my tables are recently cleaned and re-lubricated, I tear them down roughly once a year for cleaning and lubricating as preventative maintenance.

My measurements are not scientific, but they are the metrics I have available to me. Take them as you will.

On the 1229Q, there was a noticeable reduction in the noise heard through a mechanics stethoscope at the upper tone arm pivot. I use the upper tone arm pivot because that's the closest solid point before the tone arm/cartridge that I can get a good read on with the SS. I figure if I can hear noises there, it's quite possible the cartridge can also "hear" them and transmit them into the signal path. To me, the quieter it is at the upper tone arm pivot, the better.

The noise was a "mechanical like" noise prior to the new bearing and while still present, it was noticeably reduced after the bearing. That's subjective, but I did notice a reduction in mechanical noise.

There was no visible wear/damage on the original center bearing when it was removed.

I dropped the Iphone with the "Turntable RPM" app on the 1229Q before and after the bearing change for some measurements.

Before:

After:

That 0.05% is the lowest WOW number I've ever been able to pull out of this 1229Q and it was repeatable across 3 successive measurements within 0.01%..

The bearing went in "dry" as per Bruno's request. I use Audiovault's new idler wheel and it was installed for both of those tests. Nothing was changed except the platter and the center support being removed and reinstalled to fit the bearing.

Those app tests were performed 3 times each with near identical results both the "before" and the "after". WOW only varied approx 0.01% (at most) on the app over the 3 measurements. The absolute number isn't as important (IE: relies on the iphone's accelerometer accuracy and an algorithm) as the trend to lower numbers with the new bearing and the 3 consistent before and after measurements.

Another subjective impression was it seemed easier to get the strobe to stabilize the speed and stay there.

My 1249 is returning results almost the same as before the bearing was changed, but it's always been a very quiet table with WOW measurements on the app right around 0.05% on average. I'm currently still giving it a 48 hr run in, but I don't expect it to change much as this is a fairly low hour TT to start with so the bearing was likely in pretty good shape from the beginning. The 1249 also has a lighter platter compared to the 1229Q, which might mean there's less wear/load on the center bearing assembly.

Here's the 1249 app numbers before the bearing change:

Currently, when I do the app measurement, it's returning 0.05/0.06% WOW, so roughly the same as before the bearing change on the 1249. Stethoscope seems to reveal no change in the amount of audible sound at the upper tone arm pivot.

I'm not selling these bearings nor do I have any interest in Bruno's business other than buying a few things from him previously. Which, I would assume, is why he reached out to ask me to "beta test" these. I'm also located relatively close to him (same country, about 1000-1500 KMS west of me) for mailing purposes.

Final full disclosure: as a "beta tester", I did not pay for these. I have no interests in them other than that.

That's my experiences with them. You have to decide for yourself if you want to replace yours with these and/or where you want to buy them from. But from what I'm seeing, the bearing is a worthwhile installation if you have a table you're trying to chase down noises on or perhaps a higher hour count on an original center bearing assembly. Not as important if you table is already "quiet", which is an impression which seems to be supported by the numbers I'm seeing on my 1249.

Of note: the records played on my 1229Q seem to sound a little "smoother" to me after the bearing change. But that's just a likely a 'placebo" effect as i doubt I can hear the differences between 0.11% WOW and 0.05% WOW with my old, damaged hearing.

Cheers

Zitat von chartz

Here’s one of the first customer’s review.

That sounds pretty promising! Good luck to you!