Do you take your arms off?

No wonder you cant hear much difference between an Ittok and an Ekos if your putting cartridges on without removing the arm.
It takes only a little much pressure on the horizontal bearing to knacker them.
To test if your arm is knackered , make sure your table is level, turn the bias off then move the counterweight back till the arm floats freely.Now give the arm a little dudge to the side.It should swing smovly and freely with no juddering and should not come to a quick stop but move back and for untill it comes to a gradual stop.
Any small jerking or tention in the movment and your arm is knackered.

[This message was edited by jonni on WEDNESDAY 30 October 2002 at 09:26.]

What, a "little pressure" like moving the arm in and out of the rest?
I really don't understand the physics here. If the torque from the hex-wrench below is matched by that from the nut spanner (pliers?)above, and the arm is supported in its rest, how are the bearings at risk?

Sorry should read "a little too much pressure".
Don't want to worry you too much but I've learn the lesson the hard way and have a knackered Ittock to show for it.
I now use a wilson Benesch tone arm, wheres there no chance of damaging bearings due to the design.

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I really don't understand the physics here. If the torque from the hex-wrench below is matched by that from the nut spanner (pliers?)above, and the arm is supported in its rest, how are the bearings at risk?

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I asked my dealer about this last Saturday whilst doing a comparative audition on 3 carts (Adikt, DV10x4 and 20X). He insisted on removing the arm each time the cartridge was changed.

Apparently, if the arm is in-situ and locked into the rest, any pressure exerted on the free end of the arm is transmitted back down the arm, the rest becomes a fulcrum point for the forces and exerts a sideways load on the arm bearings.

He certainly convinced me and as it's only a 15 minute job to do it the proper way, why risk irreparable damage by corner-cutting - personally I'm not in that much of a hurry

David

I'm astounded. Any more views?
So is the arm just loosend or does the cable need to be removed too?

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Originally posted by Rockingdoc:
If the torque from the hex-wrench below is matched by that from the nut spanner (pliers?)above, and the arm is supported in its rest, how are the bearings at risk?

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Matching that torque by hand is actually quite a difficult thing to do IMHO, since the nuts are already recessed into their own slots in the top surface of the headshell. The nut spanner or pliers used can't therefore act on the full surface of the nut faces, and accessabiltiy of both allen-head and nut is not ideal with the arm on the deck.

Given that removing Linn arms is so easy and simple (assuming you don't use a baseboard, there's only two allen bolts to loosen, then just unplug, lift out and apply rubber bands), it seems needlessly risky to tighten up with the arm in place. You can then use the arm tube itself aginst the torque applied to the bolts, without risk of involving the bearings.

Linn have an excellent illustrated .pdf available for download about fitting and removing cartridges.

OT: So David, did the 10x4 win???

Best;

Mark

(an imperfect
forum environment is
better than none)

[This message was edited by Mark Ellis-Jones on WEDNESDAY 30 October 2002 at 09:58.]

Thanks, the Linn instructions are clear. I will obey in future, maybe.
malcolm

Malcolm,

Yes the arm has to come off (completely).

On the other subject of ittok vs EKOS, yes you're right about EKOS Mk1s. They were very close in design to the Ittok. Ekos II and III have a quite different bearing which changes the landscape significantly. The Ekos II and III sound quite different to the Ittok. In fact, it could be argued that an ARO is closer to the Ittok presentation than the Ekos. The Ekos is all about power where the Ittok and ARO are all about cohesive fluidity.

Regards,
Frank.
All opinions are my own and do not reflect the opinion of any organisations I work for, except where this is stated explicitly.

I guess I've been lucky to get away with years of (careful) bearing abuse, as I change cartridges more often than my shirt and my arms still seem to swing as required.

It is indeed an early Ekos and a late Ittok, both black, both very similar.

So do all the Rega owners take their arms off too?
I don't for that one either.

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OT: So David, did the 10x4 win???

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Almost - in fact the 20X (unsurprisingly) was the best performer on the LP12/Lingo/Ekos combination.
But bearing in mind the substantial price difference £225 vs. £350, I think the 10x4 is far better VFM and not that much inferior. DV just hiked the price up £50 on the 20X, at the old price I would go for it but .....

I only have LP12/Valhalla/Ittok VII, so my guess is the 10x4 will do me fine The Adikt performed quite well, no obvious flaws, but markedly less involving than either DV cart. Partly due to it being new out the box I think, but all the same I doubt it would out perform the 10x4 from what I heard.

David

Anybody besides me out there ever had a Materials Science class? What's the tensile strength of steel? What's the hardness of a typical bearing?
And now you are suggesting that my screwdriver, carefully applying torque to a screw in the headshell is going to exceed these limits? I think this is fantasy, no matter HOW fanatical Linn are about drumming this into their dealer's heads. I think of it as Marketing and a way to maintain control of their turntables in the after-sales service market. Taking off the arm, dressing the cable, getting VTA right, and all this other effort is beyond the level of effort most people are willing to expend on their decks so they take it to a dealer for service. I'd say, in the example provided above where the dealer is comparing three cartridges if he didn't properly dress the arm cable (which can be a royal pain!) then the results of the 'dem are completely suspect!

I've owned my LP12 for about 12 years. As far as I know, the arm has been removed when the cartridge was replaced every time but once, but after watching this process and thinking through the physics involved I really doubt that the bearings are ever at risk when changing a cartridge. And yes, I appreciate the fact that the contact areas involved are quite small which can have the effect of "magnifying" the forces transmitted from the screwdriver throught the headshell, arm-tube and into the bearing. But really, I think it's a very low risk if a person exercises a reasonable level of care.

Let the flames begin!!!!!!!!

Markus

Malcolm,

Rega have stated in the past that their arm bearings will not, under normal circumstances, be damaged by such forces incurred as when one tightens the bolts with the arm mounted.

Confusingly, none of Rega's customer provided turntable, arm or cartridge documentation makes any reference to this other than their cartridge instruction leaflets* including the warning 'This cartridge should be fitted by a Rega dealer using specialist tools to ensure the correct torque is applied'. Said specialist tool consists of a dealer provided Rega Torque Wrench, an example of which I have borrowed on occasion from my stockist.

Oddly, Rega include a small equal arm length Allen key with all of their cartridges, along with a set of high tensile stainless fasteners. Not the best way to ensure that customers follow their recommendation to enlist the services of their dealer.

Craig

*The exception here is the Bias/Super Bias leaflet which states, 'Tighten fixing screws securely to clamp cartridge as tightly as possible to the headshell' and, 'Follow the turntable or arm manufacturer’s instructions for fitting the cartridge'

I don't know the cause, but I've seen more knackered Ittok and Akito bearings than fine ones. Maybe they just need to be adjusted or something, but it seems to me the Linns are VERY delicate arms and you might as well just unscrew the effing allen bolts and take it out to change the cartridge. On the other hand, said arms seem to sound fine.

--Eric

Has anyone taken a Linn arm to bits? If not why not, is it fear of the Linn Voodoo? It is only a ball-race, surely it could be adjusted gently by trial and error, I doubt if Linn do much else.

I'm not sure some of you guys understand the fine presision tuning of tonearm bearings.
You wont "break " the arm by tightening it on the turntable but you will ruin the performance of the arm.
Arm bearings in fixed bearing arms need to be skillfully adjusted so that they have very free movment but little chatter, this take precision and it why the Ekos costs so much more than the Ittok did or the Akito.
Regas new RB1000 tone arm is essentially the same as a RB300 but has much finer torlerance bearings.
Thats the £800 difference in price.
The force of tightening a cartridge can cause a movment between the fixed potitons of the bearings if the bearing houseing is fixed to the turntable and has to take the strain.This will cause excess friction or chatter
If you damadge the bearings you are down grading your arm.

I have taken my dodgy Ittock apart but dont know how to get into the bearing housing to see if I can adjust the bearing , anyone know?

If anyone can fix my Ittock I'm willing to pay, or if you can give me some info that would be nice.

What I don't understand is that the force applied to the bearing when tightening cartridge bolts must be much less than the force applied when twisting the counterweight.

Steve B

that is what I think too, my counterweight needs brute force sometimes. I still suspect the cartridge story was all a plot to steer us away from other makers carts. and generate custom for Linn dealers, (but I may start taking the arms off).

By which mystical powers do the arm assemblers fine tune the bearings to the tune of 800 quid? Are they adjustable cone+cup types, or simple fixed ball-races. If they are fixed races they should be easily replaceable.

I fail to see how removing the arm from the turntable puts less strain on the bearings than with it fitted.I can understand the point about the arm rest causing problems,but all you have to do is remove the arm from the rest then tighten up the bolts.This is the way I have done it on dozens of different tonearms and cartridges,without any problems.

Cheers,
Paul

With the arm base not fixed ,forces can't be applied to the bearings, with the arm base fixed they could be. The point is are the bearings really so feeble that they can't stand careful cartridge fitting.

No I don't think the bearings are that feeble.I have had no problems on many different arms including Linns.I still fail to see how removing the arm puts less strain on the bearings!Can anybody enlighten me?

1) Remove arm from base board, grip headshell end of arm with a pair of Mole-grips and twist slow and hard. Re-fit arm, attach cartridge and play a record
2) Repeat procedure without first removing arm.

Can I hold the arm while usung the mole grips?

no. that wouldn't be a fair experiment

Let me put it another way then.Whats to say that the people that have damaged bearings with the arm on the table,would have done so even if they removed it,due to using a foot long bar over the allen key!