Antiskate help Technics SL1200g?...

But what if we leave the groove out of it and consider just the situation of the stylus riding on a smooth surface. Without any artificial barrier to prevent the stylus from moving inward, it will. But given that the arm makes contact with the surface of the record ONLY through the stylus, how can any force be exerted on the arm if not also exerted on the stylus??

 

The stylus is tangent to the groove, within the margin of error caused by traveling in an arc. The tangent to the groove is about 20 degrees outside the axis through the stylus and the tonearm pivot. The groove is therefore pulling axially on the stylus, but it is pulling across the axis to the tonearm pivot. That’s a sideways force on the tonearm, not the stylus.

 

Thankyou all, this has been very informative and I’ve learnt there are many more factors and considerations to be taken into account on this matter. Learn a new thing every day. Trusting what my ears are telling me, I’ve knocked the anti-skating back a notch ( there seems a consensus on this ) and incredibly there seems to be a slight improvement in an already sublime soundstage.
Also ordered a test-disc, out of pure curiosity, but seeing some posts , I don’t plan to use this as a ‘reference’.

 

This. Exactly. And using a blank disc is dead wrong.

 

You shouldnt be etching any significant lines unless your VTF is extreme. If your table needs a lot of anti skate to slowly get the arm to ride in then I suppose its just very weak.

You telling others to get a test record is also very non helpful since many test records have different modulation and placement of their anti skate tracks. Who is to say yours is right? You have no way to verify.

 

Sorry, but you telling people to use a bank disc is unhelpful and dead wrong, as I and others have tried to argue here. I mean, all you can say is to make sure the arm goes slowly inward, but how slow? How could you even measure that? Certainly eyeballing it is not going to be all that accurate. Besides, loads of people use various test records with no problems.

I wouldn't call 1.6 VTF extreme, either. Nor would I say the anti-skate in my new Rega RB202 tonearm is weak, especially when I had the same results with my Technics SL-1200.

There are just way too many variables for the blank disc method to be of any use. Not so with a test record. If in doubt, try two diff. test records.

 

Agreed.

 

The thing is that youre never going to have a "problem" with anti skating. Some use 0 and say, its perfect, well its not. Simple logic and physics dictate that anti skating is helpful for the stylus and groove longevity. But it wont exactly cause "problems".
And youre never going to have a perfect anti skating, in case thats what you think the test LP reaches. Its perfect for the test track, not most of the music you listen to most likely. The more specific you are about your listening the more specific your setting for anti skate can be.
Using the blank surface method is like using the Baerwald allignment, its the most encapsulating and average setting for best overall performance. Thats simply what the math tells us.
Remember its not me youre disagreeing with necessarily, Im just reverbalizing Ledermanns rational and studies.

It certainly is weak if you need to crank it above 1.6 to stand still or even just ride slowly in on a flat surface. My old RB101 only needs about 0.8 which is about half the VTF, same as yours.

If I try two different test records Ill get 2 different anti skate settings most likely, I mean I havnt seen them all, but what if both give different results, are we not in doubt still? Which do you choose and how to you rationalize it?

 

Clearly we are at an impasse here, a stalemate, and I'm not going to continue arguing with you even though I do continue to disagree with you. There are too many records to listen to to waste time on this. The thread starter probably has enough info from people on both sides of the argument to try to solve the problem.

 

I dont even know what part you disagree with but ok.

 

I think You are right. The force is only pulling on the needle, so there shouldn't any deflection of the cantilever due to the friction force. Only deflection should come from AS.
I wrote that the skating force should be tan offset angle, it's more correct with sin offset angle.

 

For many years I adjust VTF so that there is no distortion on the testtrack of 50 micron at 300 Hz.
Then set bias with blanc record untill arm stands still.
WHEN NEEDLE IS WORN I ALWAYS CHECK UNDER MICROSCOPE FOR SYMMETRICAL WEAR.
IT IS !!!!! SO MY PROCEDURE IS GOOD.
Bias settings have tolerance, 30 % deviations from optimum is oke, still symmetric wear needlepoint.
If bias is too different to comprehend, though its no space age science, buy a linear tracking turntable.

 

I was using a blank disc yesterday.
Arm.SME1V
Result. Same as yours.
If its correct i when using a blank disc
The arm should move slowly to the centre.
Anyway, back to reality
You were happy before. Trust Technics
And their anti skate settings.
I trust SME and can sleep at night!
A proven method is to lower tracking
Weight and, using band 2 on Hi-Fi
News test disc and try to cause slight mistracking as heard on test disc.
Adjust bias so that BOTH channels
Equally mistrack.
Now, raising vtf to previous setting
Should be quite accurate in this setting.
At the new setting band 2 should be
Cleared .
Listen for small fine detail between
Both channels.
You could set at band 1.
Band 2 is equal to the odd high cut record. If you rarely play such records
You may consider this as overkill.
Soundsmith says that most cartridges
Thst are returned have unequal tip wear as a result of OVER BIASING
Probably as a result of using test records.
When i run into sound quality issues
I set vtf at makers setting,
Level arm and match bias to vtf.
Result. Perfection.

 

I forgot. With motor on stop lower arm onto runout groove . When it lands does it move the cantilever out of line
Much. It should not.

 

It will, visibility depending on compliance.
It is the opposite of playing without bias.
Nice observation however, never thought of it.
If bias set right the cantilever, while playing an average record, shows no deviation to left or right.
But that is hardly visible, not a good way to set bias.

Long live linear trackers, no headaches.

 

Back to the original question. There IS a problem here because turning up the anti-skate should have an impact on the tonearm moving toward the spindle.
Plain and simple something is wrong if the arm "flys" to the center at all anti-skate settings.

Despite this long thread I think there are still a lot of people who don't understand where the skating force comes from. Its the component of the friction force (stylus on vinyl friction) that points to the spindle. That is actually a meaningless statement unless I tell you the coordinate system. The axis used to resolve the components is the line from the tonearm pivot through the stylus tip. So if this axis is tangential to the groove there is NO skating. That is essentially the geometry of a linear tracking tonearm. The grooves really have nothing to do with this unless they change the friction force. And I admit that possibility.

This stuff is introductory college level physics, so I wouldn't expect everyone to really understand and I know that there are a lot of people that do. But the takeaway should be that it is driven by friction and the offset headshell geometry.

 

The skating force is not limited to offset headshell geometry. A pivoting straight tonearm, such as those on some DJ turntables, would also experience skating force. How much and in which direction depends on where on the record the stylus falls. If we assume the straight tonearm is tangent to the groove at some point on the record, the skating force anywhere else on the record is toward that tangent.

 

It is not too difficult to measure the friction coefficient if you have a belt-driven TT with removable belt. I measured the JICO SAS to be around 0.33. An OM5E had around 0.45. So friction and skating is dependent on the stylus (polish).

 

My tonearm uses a spring to control
Bias. It is designed to vary as it traverses the record.
It behaved in a different manner to
Thread and weight
I trust SME and set bias to match VTF

 

my Delos tracking force is 1.75. i set the anti-skate to 1.00

 

I believe this us a very old technique for older style profile needles. I wouldn't rely on it.

It certainly doesn't work on my Roksan Nima with a Lyra Delos.

As for checking to see if it works okay, as previously posted, just set it to zero when balancing the arm, move the arm close to the spindle and turn the dial, if it starts moving back to rest you know it's working. You should also be able to stop it dead on it's return to rest by turning it back to zero.

 

Hanpin must have designed the anti skate mechanism.

 

I tried this method with the 4th (blank) side of "Second Winter". Breuer Cartridge tracking at 2g checked with calibrated Technics gauge, IIRC. It etched the vinyl. Try looking closely at the disc after you have used this method. Etching a disc is a different process from playing a groove tangentially - the friction (which will alter the anti-skate) is different. Blank disc settings are a furphy, IMHO.

 

I suppose you need more patience until the stylus suspension break in again for the new angle of the cantilever. The suspension is a rigid pivot with delayed response. It must get used to the new position. The stylus suspension is a rigid rubber donut or something like that.

I set my anti-skate visually, the AS knob numbers are BS on my TT. If the cantilever stays parallel with the grooves then the AS is OK.

 

Yet another one who doesnt understand how it works. I never said its like playing a tangential groove.