[oein]

Hello Audio Circlers!
I bought a used SME 3009 series 2 tonearm a while back and it is installed on my SOTA Star Sapphire TT and has a Grado 300$ wood cart on it, set up done by a pro here in Los Angeles. I've had on and off experience of the tonearm "luffing", or shaking side to side and jumping grooves. I thought this was a result of low range feedback from improperly placed speakers, but it's doing it even with volume level at zero and i think speakers are placed adequately far from TT.

Could the bearing in the tonearm be shot? Any other possibilities? Seems lately to only happen in the cue groove or silent passages between songs or at the very start of the side. I moved recently and music room is a subset of the garage with a concrete floor, using a decent old wood TV stand for amp below and TT on top. Might want to add a little weight (slab?) to the TT shelf... But it seems solid enough as is.

Could the Grado stylus size or shape cause this? Maybe I'll switch in another headshell, Stanton cart...(?)

Any advice welcomed. Thanks.

[John Casler]

I have that same arm and no such problem.

First things I would look at:

1) Tracking force
2) Anti-skate adjustment
3) Damping paddles or fluid viscosity and or levels

But the first thing I would DO is call the pro who set it up and ask him what he thought it might be.

[Wayner]

Well, I have to ask the stupid question and wonder if you set your anti-skating properly?

The Grado should be tracking at about 1.7 grams, also.

Wayner

[John Casler]

One other thing it might be.

While on a record, check the distance of the bottom of the cartridge from the record surface.

If it looks like it may be touching (especially if a record is slightly warped) it could be one of two things:

1) Improper VTA (vertical tracking angle)
2) Collapsing stylus cantilever
3) other

[chosenhandle]

the Grado is known to "dance", but it sounds like it is dancing right out of the grooves! I second the nomination to check tracking weight and VTA. Sounds like a long shot, but have you checked azimuth? If that is out of whack, all bets are off for other settings.

I have/had a Grado Sonata on a Triplanar and it always exhibited some dance at the start of each LP, but settled down quickly once I had the VTA and weight tweaked.

[oein]

Thank you to each of you for considering my dilemma. Very useful advice.
The pro who set up my arm did remove that suspended weight that attaches to the right side of the arm's backside...
Wonder if that would limit the dance...
I'll also try another cartridge/headshell.

[Scottdazzle]

I saw this problem once years ago. The problem was caused when the small weight on the right side (that attaches to the notched bar near the pivot) was removed.  The owner had removed that weight and adjusted tracking force using only the counterweight.  This evidently caused a lateral imbalance and the resulting "chatter" that you seem to have.  If that weight has been removed, put it back on and rebalance the arm.  This should solve the problem.

[John Casler]

I saw this problem once years ago. The problem was caused when the small weight on the right side (that attaches to the notched bar near the pivot) was removed.  The owner had removed that weight and adjusted tracking force using only the counterweight.  This evidently caused a lateral imbalance and the resulting "chatter" that you seem to have.  If that weight has been removed, put it back on and rebalance the arm.  This should solve the problem.

I think that is correct.  That weight is the anti-skating device.

Unless the set up guy is very cool in adjusting the viscosity of the damping fluid to take its place, it probably should be attached.

[Bob Wilcox]

In addition to the other points mentioned, a record with a hole that is even slightly off center can cause a tone arm to move strangely.

That old SME arm is not a good match for some cartridges. A poor arm/cartridge match can cause the stylus to wiggle on a slightly warped record. Ideally there should be no give in the cantilever when a warp is encountered. The visible gap between the stylus and cartridge body should remain consistent and the stylus remain centered with respect to the cartridge body as a warp is tracked.

[oein]

Thanks again. Yous guys' advice is worth more than I can say.
There seem to be several issues hindering proper performance of my rig; surprised I've had as many (several) decent plays as I have, or at least thought I was having. I just moved, so this is a re-setup I'm doing in a newly drywalled part of the new garage.

First I replaced the Grado headshell with a Stanton 680HD or something like that number (bought from KAB several years ago for the Tech 1200 and numark T100 dueling radio-style set up. Not sure how the cart balanced (at same weight set for Grado, probably a little heavy with the Stanton, identical Stanton headshells) but the Stanton played records fine in all the spots it was dancing and skipping inward with the Grado.

I returned the Grado headshell and tried to add some weight to the headshell and sure enough, I discover the black undercarriage of the cartridge is touching the record. So yes, the vertical angle is too low for the Grado. (I didn't notice any cantilever collapse thought.) Gotta get out the allen wrenches and mess with this baby a bit. Will also look for the anti-skate weight and try to attach. Have no idea how my genius pro setup guy could have decided to leave that off as well as get the VTA wrong. He also rebuilt my SOTA vacuum which I can't tell if is currently working, since move.

I also discovered that the headshell tightening ring on the tonearm is not holding the headshell perfectly vertical, I mean: I can twist the headshell around on the tone arm both clockwise and counter when it's supposed to be locked down. Fixable? It more or less stays put, but it sure is an issue. No wonder I got the tonearm for such a good price... Ugh. Thoughts of simpler TTs dancing in his head...