Anti skate setting using blank disc

ok thank you

 

CDs consist of three layers of materials: A base layer made of a polycarbonate plastic. A thin layer of aluminum coating over the polycarbonate plastic. A clear protective acrylic coating over the aluminum layer.

 

I would think that if anti-skating is set correctly it would be evident by an even channel balance on each of the three test tracks.

 

Are we talking about the HFN tracks?

It has 12, 14, 15, 16, and 18db tracks with the 15db repeated three times (first, middle, last tracks) on the flip side from the others.

You aren't going to find many albums with a recording level that exceeds the 12db track.

In the "olden days," we would play test tracks and reduce VTF until the onset of mistracking, then either slightly increase VTF, or (if the tonearm supported it) adjust the anti-skating to equalize the distortion between the two channels.

When you were done you had the trifecta: A setup that should play most any album in your collection while minimizing vinyl and stylus wear.

 

Oh and FWIW, each time I've used the 12db test track method and then checked the stylus on ungrooved vinyl, the result approximates the desired behavior described by the SoundSmith gent.

 

It is too hot, but it's easy to make fine adjustments because the racket being made sounds horrible.
Get the horrible noise balanced and you're done.

 

The skating effect is based on the offset angle of your stylus/cartridge, arm length and VTF.

 

That’s essentially the point I was trying to make. When anti-skate is properly set, the two channels will sound balanced on all of those test bands, regardless of how “hot” they are. The audible distortion becomes a useful tool for fine-tuning AS, as you said, and I think that was the intent.

 

That bad idea for people to use a blank disc has caused too many people to misunderstand and incorrectly set anti-skate. You now have definitive proof of that.

 

You can use a blank disc if it’s vinyl....it should stop and stay in between the spindle and the lead in....

that will get you close, then do a balance check...

it should be pretty close to whatever your cart VTF is...

 

Well companies like Shure have included ungrooved vinyl sections on their test albums for the purpose of evaluating anti-skating. They (Shure) seemed to know what they were doing.

Still many people have arms with bearings with too much static friction, which can cause all sorts of trouble setting anti-skating, regardless of method.

 

Anti-skate? (LP)- Vinyl Engine

 

Skating force varies across an LP's width. Skating force varies dependent on arm length, and by pivot type. Skating force varies dependent on groove modulation aka 'loudness'. Whilst it's true that listening for channel balance equivalence is a reasonable approach, that is also affected by azimuth, and VTF, and cartridge alignment (which varies dependent on stylus tip profile). This is why it's best to simply set up your arm and cartridge so it's sounds good to you, and leave it at that. There is no objective 'scientifically perfect' setup, at least not if what you want to do is listen to vinyl LPs on a turntable.

 

I run 4 different stylus shapes and the blank disc does not care which stylus shape it is. Stylus shape has very little to do with it.

 

Same here, at least four shapes.

 

What people need to understand is that there is no perfect Anti Skate, just like there is no perfect Alignment, Azimuth or SRA. Only VTF has something that is a perfect value across the board.

When you set Anti Skate you need to worry about several things depending on the method.
For blank discs, where on the disc am I dropping the stylus, what material is the disc etc, CDs are flat compared to most records which are uphill for the stylus.
For test records, what modulation is the track Im using, will balancing the distortion really balance it for my records if they are less modulated?

Only if we have a machine that knows all your records individually and how exactly the modulation changes through a song and adjusts on the fly can we have perfect Anti Skate, this does not exist.

We know 0 is wrong and we know there is such a thing as too much. But anywhere in between can be optimal.
So just set it around the ballpark and try some demanding records, usually theres no sound difference, but if you hear distortion try to mitigate it.

 

The effects of AS vary by the alignment also. If you will notice the top curve that shows tracking error in relationship to the null points. Traxking error means the stylus is not "square to the world" while in the groove, so for a time, one surface or the other is ahead (or behind), time wise and causes a drag.



BTW, this curve happens to be the results of my own designed alignment I call the Baergren alignment, as it is a blend of a Baerwalds and Lofgren B. Its designed for those that have tables that just can't reach the Lofgren B alignment, like those who own Technics 215mm pivot to spindle, 15mm overhang.

Using the blank disc, I will say that it will let the vintage table owner know if the AS control even works, especially on spring loaded machines. On most of my tables, the arm will stay in place almost anywhere I place it. If you care to lean it towards a slight drift to the spindle, that is a user preference. Technics tables have about 1/2" area at the beginning of the record where the AS has no effect (designed that way) to ease in beginning of play stylus drop using the cue.

'ner

 

These graphs are completely independent from AS though, they only deal with alignment.
The alignment will have an affect on the AS as the angle changes the perpendicularity, but this is minuscule, it only changes by a few degrees as you can see.

 

It has a very small effect, but explains the reason why AS will vary across the playing surface of the record, hence, the reason for the post.

Again, the main contributors of the skating effect are VTF, offset angle and arm length (which is a component of offset angle, the longer the arm, the less the offset angle).

 

Elements like arm length, offset angle, and overhang are related and dependent on each other. One can’t really be isolated as a cause without the other. If a tonearm had no offset angle but was nevertheless placed on the record at an overhanging position or an underhang position it would skate. That’s what happens with the DJ turntables that have a short and straight tonearm. They skate until they reach a tangent position and then they skate the other direction. It’s the overhang or underhang causing the skating, along with the friction.

 

So we're all agreed then, there is no empirically correct A/S setting for any particular record on one turntable/tonearm/cartridge combination, so the 'best compromise' is the closest anyone can get i.e. what seems to give the best aural results.

 

In my experience, the same issues which contribute to end-of-side distortion are also most sensitive to anti-skating.

So I make sure my anti-skating favors those albums which push the envelope on inner grooves.

For example, I've got some piano recordings which are really hot on the inner grooves. I tinker with anti-skating weights in .25g increments until I get those recordings to play properly. Interestingly, a .25g adjustment up or down on my arm translates to just about 30mg out at the stylus, but can be the the difference between distortion and none.

 

The offset angle does have a relationship to the record grooves, but if there is no offset angle, but on a pivoting tonearm, its a disaster. The you would not have just a degree or two of tracking error, you would have 10 or 12° of error. Who ever thought of putting a straight mounted cartridge on a straight tonearm had no clue to the geometry of the process.

Linear tracking tonearms is more in the line of my thinking, unless you have a 4 or 5 foot tonearm, then the offset angle nears zero on a pivoting tonearm. That length of tonearm probably will not benefit from AS, but it will have different kinds of problems.

Of course, Evan Holm had a completely different idea: Submerged Turntables — Evan Holm

Or: Antique Sound — Evan Holm

 

Those short arms are typically intended for use w/ spherical styli, a very special use case.

 

picked a bad day to stop taking acid...