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Zeta Tonearm VTF Drift

AKprentice

pfm Member
I have a Zeta tonearm on a Linn with Lyra Skala cartridge. I have found several times now that the VTF has drifted off by 0.1g - 0.2g after only a couple of weeks. The counter-weight is locked in place with a set screw, so I don't see how it could move. The cartridge screws are tight enough, so that is not moving either. I verified that the turntable was still level. I am using Riverstone Audio digital scales, and verifying with 2g cal weight that they are reading correctly.

Has anyone seen this type of issue before - it is driving me a little crazy!
 
Likely sticky bearings, sadly they are famous for it (the oil gradually turns to glue), i.e. the tracking weight is the same, but the friction in the bearing is preventing a consistent reading. Basically it needs a service. Audio Origami come to mind here, I’d expect Johnny to have seen a Zeta before as it is a well documented issue.
 
I had a Mission 774 SM which was made by Zeta and it used to stick.

Sent it to Johnnie at Audio Origami. Had it rewired at the same time and it came back like new. Highly recommended.
 
im not sure what those spares would be? lol.
if all else fails you can spray wd40 or any other oil dissolving agent through the 2 holes on each bearing cap cover,then when dry add some oil. i must admit to not knowing about zeta's needing oil when i rebuilt the 3 i owned. perhaps if its well documented someone can post a few links on the subject?
 
I heard back from Johnnie and he no longer works on Zeta's due to lack of available spares.

Oh, that's a shame. I have a Zeta and mine seems to be working fine, but the lack of servicing would limit ones options for the future. I don't know of anybody else in the UK that undertakes tonearm repair or servicing.
 
im not sure what those spares would be? lol.
if all else fails you can spray wd40 or any other oil dissolving agent through the 2 holes on each bearing cap cover,then when dry add some oil. i must admit to not knowing about zeta's needing oil when i rebuilt the 3 i owned. perhaps if its well documented someone can post a few links on the subject?
I saw your thread on rebuilding the Zeta, but in both places the images were no longer showing. Is there a location where the post is still intact, if I have pictures I might have a go myself.
 
If the bearing was oiled, oil doesn't "dry out" or suchlike, it can just pick up dust and rubbish though, so the bearing will need a good clean.
If the bearing was greased, grease is just mineral oil mixed with a metal soap. The oil evaporates or drains away, leaving the waxy soap. This would also need a good clean.

Unless you expose the bearings, I would not trust anything to clean them up just by a simple flushing through.
 
I’m actually surprised he needs spares, I’d have though a strip-down and thorough clean would do it. I’ve never pulled a Zeta apart though (I did own one, but it was fine so no need). I guess it all depends on how the bearings are mounted, as really you’d want to get them out of the arm and soak them in something that would dislodge the sticky oil.

PS One reason I like my humble 3009 is I know exactly how it works, how to strip it down etc! I can keep one of those working perfectly for the rest of my life for sure!
 
If it is a simple gimbal arm, I'd be astonished if there was anything that could not be replaced either off the shelf or very simple, basic refabrication. No matter whether imperial or metric, bearing in particular are all still available,

When looked at against a simple strip, clean rebuild, the chances of screw-up must be close to zero.
 
It all depends on the way the bearings were installed, i.e. whether it was designed to be repairable. I obviously know exactly what a Zeta looks like, I had one for years (and I still visit it, a friend has my old Linn), but I never removed the bearing covers so I’ve no idea if the bearing races are a tight interference fit or whether you can get a puller anywhere near them. This arm dates from the “rigidity is everything” era of the early 80s, so it wouldn’t surprise me if the bearing races weren’t pushed in as a ‘one way’ process. I don’t know, it was a very solid arm and I bet they never factored the lubrication failing.
 
I’ve just found a few teardown pics on VinylEngine. The bearing assemblies aren’t how I had mentally pictured, so may actually be easier to work with. It actually looks to have loose balls, I was picturing distinct races.
 
I'm in the if it aint broke then don't fix it camp tbh. Mine seems to be ok as far as I can tell, though I can't honestly say I've been looking for faults. It's a beautiful looking thing & I do like the integrated arm rest. I made my own arm board and bolted the Zeta firmly to this, but left the arm board relatively lose on the plinth. It's very well matched to the slate plinth I have on the Lenco 88. Regarding J7, then obviously he's free to pick & choose what he works on; he declined to rewire my Audiomods too.
 
I have a Zeta with later serial number so theoretically improved bearings etc, J7 did rewire and service it for me a couple of years ago and works a treat so far. However I do not think it is a question of spare parts being needed but a careful strip down and flushing out of the bearings and appropriate lubrication applied and then reassembled but not too tight.
The Zeta like the Mission Mechanic arms are wonderful battleship tough designs that should last many years if handled carefully and are one of my favourite tonearms plus they are British built. There was someone who refurbished his Zeta here on PFM a while ago so it can be done and I suspect J7 is extremely busy at the moment.
 
I can understand J7's concerns. If I strip the arm down myself and damage something then I can spend the time to hunt down replacement parts, find someone to fabricate them or decide to accept the loss. For J7 he would be taking money to work on someone else's arm, he could not afford the time to hunt down replacements and trashing an arm would be bad for his reputation. If he has plenty of work, why take on the risk?

I did notice an omission my original post, forgetting to mention that I had the Zeta serviced and re-wired with VdH wire by Moth in 1997 (I believe they hired the engineer from GB Tools who used to build Zetas etc). I am not sure whether they would have applied fresh oil/grease at that point (or left it without), certainly 20+ years in California will have a drying effect. As an alternative cause, could there be tension in the wiring? I had a cartridge fitted 5 yrs ago and the dealer insisted on adding colored heat shrink to the cartridge tags (but got the colors wrong!). In looking closely it seems that there is more wire exposed at the head shell end than there used to be, so it could be tight going through the bearing.

btw I realized I had mentally upgraded my cartridge when I made the first post - I have a Lyra Kleos, not a Skala. Unfortunately, being a "New Angle" design, sound quality drops off very rapidly if it is outside of a very narrow 0.1g window.
 


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