Tonearm doesn't drop vertically (problem ALMOST solved)

peace_sells

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Hi guys. I had this problem a few months ago with my Technics SL 1500 (Audio Technica CN5625AL cart). However the problem was solved when I increased the tracking force of the cart from 1.5 gms to 2-2.1 gms (as suggested by Kuruvila Sir from whom i bought the TT. Recommended tracking force for this cart is 1.5 - 3 gms).

Now this problem returned a few days ago : When i raise the tonearm using the lifter, place it over a groove and then drop it, it drifts a bit (away from the record label in the direction of the armrest)...it doesn't drop straight.

So i did some reading over the net and some guy suggested : "Best is to find a grooveless record. Set the anti-skate on 0 and place the needle in the center of the grooveless record while it's spinning. Slowly adjust the anti-skate until the tonearm stays in place without drifting in either direction"

I did this and it worked! Well..not quite. By trying the above method, the antiskate that i ended up with is close to 1.4/1.5 (earlier the antiskate was at 2-2.2). Whereas my cart's VTF is set at 2.1..Isn't this wrong? Shouldn't the antiskate be the same as (close to) the VTF?

Am I missing something here? Does this problem arise just because of a wrong antiskate setting or could it be something else? Is there any other way to rectify this problem?

Cheers,
Saket.
 
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if the tone arm shifts position while dropping, there can be only 2 reasons:

1) the lift platform is not properly aligned
2) incorrect anti-skate settings
3) hinderance caused to the arm by the tonearm wires or mechanicals near the pivot

this is easy to fix
 
in some rare cases with old garrards, i once noticed that a deformed headshell caused this problem

increasing the VTF is not a solution for this problem. its like taking paracetamol to mask fever without actually trying to find out the root case of the fever :)
 
I have a feeling the anti-skate could be the culprit. I think the antiskate value that is shown on the dial is not the actual value (maybe the zero mark on the dial does not correspond to the actual 0. Since the TT was refurbished, there might have been an error in re-setting the antiskate dial..is that possible?). What do you think about the grooveless record method? Is that a correct way to set the antiskate?
 
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if the tone arm shifts position while dropping, there can be only 2 reasons:

1) the lift platform is not properly aligned
2) incorrect anti-skate settings
3) hinderance caused to the arm by the tonearm wires or mechanicals near the pivot

this is easy to fix

The tone arm shifting could also be caused by wrong vtf. However vtf is a known quantity and setting it accurately is easy as long as one has a stylus force gauge.

If the tone arm shifts inspite of the correct vtf and anti skate dialed in, normally it means there is something wrong with the arm's pivot.
 
Now this problem returned a few days ago : When i raise the tonearm using the lifter, place it over a groove and then drop it, it drifts a bit (away from the record label in the direction of the armrest)...it doesn't drop straight.


More specifics needed: does the arm drift slightly when being dropped even before it hits the surface of the record? Or is it begins drifting as soon as it hits the record surface?

If it is the first case, arm lift is the culprit.

If it's the second case, it is something to do with tracking weight and/or antiskate.
 
More specifics needed: does the arm drift slightly when being dropped even before it hits the surface of the record? Or is it begins drifting as soon as it hits the record surface?

If it is the first case, arm lift is the culprit.

If it's the second case, it is something to do with tracking weight and/or antiskate.

The drifting begins before the needle touches the record surface. After that the tonearm doesn't move weirdly.

So according to you arm lift is the culprit? How do i sort it out? (I'm very new to TTs :p)
 
The drifting begins before the needle touches the record surface. After that the tonearm doesn't move weirdly.

So according to you arm lift is the culprit? How do i sort it out? (I'm very new to TTs :p)

I don't know if this applies to your arm lift as well, but in my case the screw that fixes the arm lift to the arm base needed to be tightened. As it was loose, it could rotate slightly and when the weight of the arm rests on it and is lifted, it used to rotate slightly. In my case, the screw (hex screw, in fact) is tightened from below and so tonearm needs to be removed completely.
 
The drifting begins before the needle touches the record surface. After that the tonearm doesn't move weirdly.

So according to you arm lift is the culprit? How do i sort it out? (I'm very new to TTs :p)

This is possible, however could be a rare occurance. Over the limit anti-skate can cause one-sided groove wear on your records, irregular stylus wear and more importantly, at the slightest provocation, your stylus will repeat the groove it is playing. Generally, without making things sound too complicated, the antiskate can be set to a similar setting as the VTF. For example, if your tonearm is tracking at 2 gms, use an antiskate of 2 gms. This is the simple way forward.

However if you are quite critical and want the exact setting, then you'll have to follow the calibration process. Use a groove-less disc (its easy to get a piece of perspex or acrylic cut in the shape of an LP record (don't forget the centre hole). Put this on your turntable and spin it. Place the tone on the spinning piece of round perspex, it will hop across the the spindle area and auto return (if you have that feature on your TT). Repeat the procedure and get the exact point wherein the tonearm stops hopping and stays put on the place where you lower it on to the perspex piece. That's your correct anti-skate setting for the cartridge and VTF which you are using. Please note that you will have to repeat this process, every time you change your stylus, cart, headshell (obviously whenever you change or re-calibrate the VTF settings).

On another note, if you tone arm actually struggles to stay put where you drop it and actually attempts to hop back, in the reverse direction (towards the outer edge) then your tonearm's antiskate is over the limits and you will have to turn your TT in for repairs.
 
However if you are quite critical and want the exact setting, then you'll have to follow the calibration process. Use a groove-less disc (its easy to get a piece of perspex or acrylic cut in the shape of an LP record (don't forget the centre hole). Put this on your turntable and spin it. Place the tone on the spinning piece of round perspex, it will hop across the the spindle area and auto return (if you have that feature on your TT). Repeat the procedure and get the exact point wherein the tonearm stops hopping and stays put on the place where you lower it on to the perspex piece. That's your correct anti-skate setting for the cartridge and VTF which you are using. Please note that you will have to repeat this process, every time you change your stylus, cart, headshell (obviously whenever you change or re-calibrate the VTF settings).
That's exactly what I did. I used a grooveless record (I have a record where there's no music on side D) and re-calibrated the antiskate till the tonearm became stationary on dropping the needle onto the vinyl. Now the tonearm drops vertically downwards without any lateral movement in the air. My only concern is that the re-calibrated anti-skate has turned out to be 1.4 when my VTF is 2.12 gms.

I don't know if this applies to your arm lift as well, but in my case the screw that fixes the arm lift to the arm base needed to be tightened. As it was loose, it could rotate slightly and when the weight of the arm rests on it and is lifted, it used to rotate slightly. In my case, the screw (hex screw, in fact) is tightened from below and so tonearm needs to be removed completely.

That makes sense. Will check that.
 
So much confusion about a matter that should seem fairly obvious.

Anti-skate is a force designed to move the tonearm/cartridge combination outwards to the LP edge to counteract the vector force (moving inwards) created by the angled cartridge(vis-a-vis the tonearm tube) WHEN the stylus is IN THE GROOVE.

When you lower the tonearm, anti-skate is still active, well before the stylus hits the LP. Until it touches the LP the vector force is not activated. Which is precisely why there will be a drift outward. There HAS to be a drift outward, and that only confirms that your anti-skate mechanism is working fine.

The drift may be less noticeable for heavier VTFs, or where the anti-skate is not calibrated properly. Most tonearms vendors recommend the same number for the anti-skate as for the VTF, but you could always experiment with slightly lower numbers for anti-skate, depending on your tonearm make. A calibrated Test Record is the best way to confirm that there is equal tracking pressure on each side of the groove. Some manufacturers, like VPI, dispense with anti-skate altogether.
 
One reasonably accurate way to check whether your arm's anti-skate is calibrated correctly is this:

1. Set it to the same number as the VTF recommended and set for your cartridge.
2. Then, while playing the opening track of an LP, get up close and eyeball the cantilever with reference to the flat undersurface of the cartridge. A good illumination lamp and magnifying glass does help. Careful here not to get too close and damage the entire delicate thing.
3. The cantilever should be dead vertical, then everthing's hunky dory.
4. If the cantilever is angled inwards towards the record label, then anti-skate is set too high. The stylus is holding on to the groove, while the rest of the arm is being pulled outward. Reduce accordingly till vertical position is attained.
5. If the cantilever is angled outward, then anti-skate is set too low. Same principle.

These deviations from vertical will show up prominently only if there is a gross mismatch in anti-skate and VTF. Your ears will also tell you so, if there is marked mistracking. For lesser variations, it's best not to get too paranoid.. Just go with the recommended settings and enjoy the music.
 
Hello Saket,

Make sure that the TT is itself placed on a level surface. Check if the tonearm wires have proper slack so that the arm is free on the pivot. Anti-skate setting has a spring inside and the spring can lose its proper tension over a period of usage. I will share my experience which I had while refurbishing my tt. The anti skate setting spring has lost its proper tension and hence had become loose. This meant that a setting of 2 was not actually 2, it was a tad lesser like 1.5 or so. For this I increased the tension of the spring.
To check if your anti skate in functioning, remove the headshell & stylus from arm. Set anti skate to 0. Re-balance the arm to keep it hovering over a stationery record. Now increase the anti skate. The tonearm should be 'pulled' back towards the tonearm rest with increase in anti skate values.

Regards,
Saket
 
Hello Saket,


To check if your anti skate in functioning, remove the headshell & stylus from arm. Set anti skate to 0. Re-balance the arm to keep it hovering over a stationery record. Now increase the anti skate. The tonearm should be 'pulled' back towards the tonearm rest with increase in anti skate values.

Regards,
Saket

Just one more point to the above. The counter weight needs to be pulled back completely. This really helps to check if the anti skate is working correctly or not.
 
Sorry that I missed reading this post as I was travelling during the last few days. I would request peace_cell to call me. Recently, there was a thread started by olly42 and many suggestions were put forward but when he called me, I gave him some suggestions and he was able to correct the problem. I know this player because I sold it to peace_cell and I may be able to sort it out or consult my mechanic who had serviced it. I now understand that when the arm is lowered, it first moves vertically down but before it touches the record, it sways to the left. Correct me if I have understood it wrong.
 
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