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New Bearing for LP12--The Karousel

cre009 said:
A while back I did some testing of several of my belt drive decks and found that there is some speed drift during the session.
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Did they get faster or slower?

I think all drive systems are a compromise and belt drive is probably the worst. It harks back to the days when motors were noisy and belt drive was the cheapest way to build a record player. I'm very surprised the speed stability on the RP10 is as good as it is but my bet is a direct drive is still better.
 
sunbeamgls,


1. In response to post 72 of this thread you posted a link showing large stylus accelerations.

2. I responded as follows: “Even at the high accelerations that occur in record replay, the forces are minuscule in magnitude due to the low effective mass of the stylus and will have negligible effect on the bearing and its housing”

This is quite correct. Why don’t you do some back of the envelope calculations and see for yourself?

Your comments below are not relevant to the discussion above.


sunbeamgls said:
Exactly. You said it, miniscule in the macro sense, but tiny inaccuracies at that miniscule level have a big impact. So any miniscule inaccuracy in the equipment supporting the stylus means quite a large impact on its miniscule movements. You're looking at it the wrong way around. Because the movements are so miniscule but massive at that scale, any inaccuracy in the bearing has a big effect on the effectiveness of the stylus.
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I have just taken a look at the original link.

LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLOL, what a total load of hooey.

Whatever it does or does not do, a great deal of the information is nonsense. Just apply some basic lubrication facts/theory/knowledge for a start - if a lubricant is achieving what it should, it forms and holds a film between otherwise mating parts - you know, the centre of the spindle and the thrust plate at the bottom of the female bearing part. If it does not do this, it isn't a lubricant.
 
Vinny said:
Whatever it does or does not do, a great deal of the information is nonsense.
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Interesting you should bring the oil into it. When I got the Cirkus I thought it was a big deal. Well worth the £360 it cost back then. Years later, when I switched from Linn black oil to Audio Origami oil I reckoned that the improvement was in the same sort of ball park as the Cirkus bearing was!
 
LP12 bearings are lubricated, if the lubricant is chosen correctly, none of the bearing parts touch.
In the real world, but very much less so with an LP12 bearing which is low rev' and well shielded from the outside world, ingress of debris and wear products become abrasives, suspended in the oil, which lead to (further) wear.

So far as lubricant choice goes, there are an awful lot of simple guides online, some including calculators to include spindle speeds etc.
 
Just put ep 80 in it with high pressure additives if you fancy, graphite, molybdenum, ceramic particles. If it's good enough for gearboxes a tt bearing going round at circa 840mm a minute is nothing.
 
Graphite in oil achieves essentially nowt. Graphite is only a lubricant with adsorbed water - graphite is never used in vacuum or dry/inert gas atmospheres for precisely that reason.
 
Mr Pig said:
Did they get faster or slower?

I think all drive systems are a compromise and belt drive is probably the worst. It harks back to the days when motors were noisy and belt drive was the cheapest way to build a record player. I'm very surprised the speed stability on the RP10 is as good as it is but my bet is a direct drive is still better.
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My recollection is they got fractionally slower but I ditched the transfers last year to reclaim hard drive capacity. I want to have a further go in the near future and try to be more particular at trying to spot any variables and making sure my findings stand up.

I was actually trying to investigate the impact of belt age and wear on speed at the time because some of what I observed seemed to be counter intuitive. For example the old belts I got with my AR XAs seemed to run fast when I was expecting the opposite.

I have been checking speed stability on my decks over the last few days because I keep seeing this thing about DDs and in particular the latest Technics having impeccable stability and all other decks (name any brand) warbling like hell.

I have some old test records from the 70's and 80's that have checks for wow and flutter. I have been using a BBC disc because that has both a single tone for checking and follows it up with some piano. After warning me that my stylus must be in first class condition it then goes on to mention that the causes of wow and flutter can be legion and specifically mentions worn bearings and flats on the drive wheel. Based on this I checked the bearings on both my LP12s and my Castle built RD11. Spin down time on the RD11 was poor indicating bearing wear so I slipped a delrin thrust plate into the bearing and this improved things a bit. I couldn't locate the drive wheels on my LP12s! but the wheel on my 301 looks ok. My Decca test record warns me to listen close to one speaker otherwise standing waves may be an issue.

Anyway after doing the test on several decks including 2 direct drives (PS-X7 and Technics SL D202), my 301, both LP12s, my IIX 900 and the RD11 none showed any pitch instability that I could hear close to the speakers with none better than the others. However the single tone from the normal listening position certainly indicated that standing waves or other room reflections such as flutter echo could be an influence on what people hear.
 
cre009 said:
Anyway after doing the test on several decks..none showed any pitch instability that I could hear.
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I can hear pitch instability on all of the turntables I have owned. A test tone is not ideal as different types of instability will show up in different ways, so some turntables are poor on some records, other turntables poor on others.

The Lenco idler drive I had was pretty good. The LP12 is good in some ways, very poor in others. The RP10 is very good with only a slight wobble detectable occasionally. Much better than the Linn. I've never owned a direct drive.
 
Direct drive t’tables used to be frowned upon, I recall.
Perhaps they’re more acceptable these days...

I am setting up a vinyl playing system for my son and went for a DD turntable, semi automatic.
Works well.
 
Martyn Miles said:
Direct drive t’tables used to be frowned upon, I recall..
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Mostly by the people who couldn't make them ;0) As far as I am concerned all drive systems can work fine and all have their potential issues. I'd buy a deck on sound, not on how it made the record go round.
 
Vinny, graphite is added to 100s of oil and greased based lubes and used dry in sliding bearings. Where it's not used is in electrical environments.
 
Cheap Japanese DDs eliminated potential belt issues but typically lacked both sufficient motor torque and flywheel affect. We used to fit the more massive aftermarket mats to good effect on both the lower end Technics DDs and BDs, back in the day; this for improved flywheel affect, more so than for improved platter/record damping.

Out of the box, there were really no performance differences between the lowest BD and DD models. Given time, the cheap BDs went off rather quickly due to their tiny motor pulleys necessitating that the belts be both tight fitting and of high elasticity; the latter a requirement in order to retain the belt round the inner drive rim during transit/storage, whilst also allowing for it to be easily stretched out over the tiny pulley (otherwise, Japan Inc. would have had to go for costly separate platter/sub-platter metal with stiffer belts, which wasn't on).

At the higher end, Japanese DDs were way out in front, having ample motor torque combined with somewhat greater platter mass. The PLL, and later quartz, speed control circuits were really just the technological icing on the cake; necessary to maintain a given speed, but not the overriding determinant of speed consistency (IYSWIM).
 
Re: Linn 'Black' oil; I swear that my old Civic ran quieter when I dumped a can of Molyslip E in, too.
 
I think it is great that Linn are continuing to develop the Sondek and making new developments retrofitable. I will be taking advantage of this just as I have taken advantage of the possibility of upgrading my KDS to its latest specs. This is an attraction of Linn. Anyone tried to upgrade a Rega P9 to a P10? Or a Naim NDS to a ND555?

It is strange; here is a thread full of accusations that Linn are greedy and earning more money than they should. Recently there a was a thread gleefully reporting that Linn are unprofitable and may not have a future.

Admire them and be thankfull.

Best regards

Hans
 
Graphite is best used "dry" - door locks, watches (mechanical) etc, no stickiness to pick up and hold on to dirt/contaminants.

I didn't think that there was much point in putting graphite in to an oil or grease, although graphite works well if mixed with an oil/solvent which boils off at low temperatures. I think the idea is that the solvent just transports the graphite to where it is needed and distributes over the contacting surfaces.
Graphite won't work well in aqueous phases as it is hydrophobic ("hates water") and will just clump together.
 
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