Just thought I mention my way of setting the anti-skating that I devised some time ago. Having no test record of any kind and no blank single-sided records to test the accuracy of the anti-skating dial on my TT I came up with this idea:
How about using a brand new, pristine cd (or a cd-r) flipped shiny side up placed on the centre of the platter and letting the arm glide on it to see if it stays put or moves either way?
I have a record clamp that makes things even easier by keeping the cd firmly in place, bit it works without the clamp as well.
To my surprise my TT's antiskating gauge seems very accurate: at 1.5G tracking force and 1.5 anti-skating the arm stays put and doesn't move sideways. Any adjustment of the anti-skating dial will make it slide either to the centre or outside of the cd.

Kris

sounds like a good idea...but those with expensive cartridges will no doubt be a little 'nervous' :D

I'll have to try this! I have used a Shure test LP but it's quite old and grooved.
Tom

Kris,
If science is theory corroburated by experimenting, you certainly are a scientist.
Great to see real intelligence at the service of this hobby of ours; We can only benefit from it.
Jorge :thmbsp:

Kris,
If science is theory corroburated by experimenting, you certainly are a scientist.
Great to see real intelligence at the service of this hobby of ours; We can only benefit from it.
Jorge :thmbsp:
Thank you Jorge - I'm flattered :)
Kris

I wonder if the friction levels of polycarbonate differs from that of vinyl. (Though of course a blank disc is bound to have a different amount of friction than a grooved disc, and anyone playing discs from the 70s and 80s isn't neccessarily playing virgin vinyl). And what happens when the needle goes off the edge of the CD -- ouch!

Judging by the comparison of the score marks left by a stylus on the cd surface and the blank, "groove-less" portion af a typical vinyl record close to the spindle hole both materials are of a similiar softness, thus suggesting similiar friction levels.
This test is by no means perfect, but it serves its purpose of establishing an approximate value of the anti-skating force needed.

As for the small size of the cd and a danger to the stylus it presents - I actually use a laser disc if I don't feel like holding my hand close to the headshell at all times in case it slips... but cds are just so much easier to obtain and work on the same principle. Laserdiscs being a bit of an obscure variety.
Kris

I wonder if the friction levels of polycarbonate differs from that of vinyl. (Though of course a blank disc is bound to have a different amount of friction than a grooved disc, and anyone playing discs from the 70s and 80s isn't neccessarily playing virgin vinyl). And what happens when the needle goes off the edge of the CD -- ouch!

The skating side thrust is the result of the two grove walls contacting the stylus. A gloveless disk will not tell you much. The HI-Fi News test record is the best bet for setting this.

Ron-C

The skating side thrust is the result of the two grove walls contacting the stylus. A gloveless disk will not tell you much. The HI-Fi News test record is the best bet for setting this.

Ron-C

So I guess what you're saying is that if your anti-skating value is set at zero, your stylus should stay put on the spinnning groveless record and only experience the side thrust if it's riding the groves?

Nope. You said that. Since many anti-skating devices use a spring the springs vary so setting it a zero will be different with each arm. I am not defending this it is just the way arms are made.
If you use a test record with groves at various velocities you can set the anti skate dynamically. The higher velocity grooves will simulate what happens when the stylus is playing a very loud music passage which is where the miss-tracking is most common.
Ron-C

The skating side thrust is the result of the two grove walls contacting the stylus. A gloveless disk will not tell you much. The HI-Fi News test record is the best bet for setting this.

Ron-C

Correct.

Common myth, to adjust bias on a smooth surface. Learned more about this from Wally at a seminar he put on at the Rocky Mountain Audio Fest last year.

Nope. You said that. Since many anti-skating devices use a spring the springs vary so setting it a zero will be different with each arm. I am not defending this it is just the way arms are made.
If you use a test record with groves at various velocities you can set the anti skate dynamically. The higher velocity grooves will simulate what happens when the stylus is playing a very loud music passage which is where the miss-tracking is most common.
Ron-C
OK, I understand.
So, will playing a groveless record help you to check antiskating in any degree at all? I don't think I can find any test records available locally (in Canada) no matter how hard I look.
Also, when you get a test record and it just so happens that your antiskating is off, won't that cause your cartridge to mis-track and consequently damage your test groove thus rendering it useless?
Which would mean that you have to start with a correct setting to begin with?
BTW, I'm really asking these questions to learn, not to just argue, I swear.
Kris

I once did some experiments with the blank section of the Shure Audio obstacle course disc and a Dual 510 table. I found that when I set the adjustment to hold the arm still on the disc, the anti skate setting was exactly where the scale on the anti-skating adjuster said it should be, for the tracking weight that I was using.

Don, so true, but then you should listen to the tracks that reveal mistracking due to skating to see if it can be further improved. Shure knew what they were doing way back then when they cut that test record.

Think about this too. It's possible that the resulting friction that occurs with the needle riding on the bare plastic may approximate that of the friction between the needle and groove on a grooved record. It is, after all digging its own groove.

The adjustment using this method may be a lot closer than some think. :yes:

Doug

The skating side thrust is the result of the two grove walls contacting the stylus. A gloveless disk will not tell you much. The HI-Fi News test record is the best bet for setting this.

Ron-C
I would be very careful with the hi fi test record. I also have that, but if you are (as many do) setting your anti skating to do as well as possible on the torture test track side, you are setting it much to high. They are located at the end of the album side, which is where the strongest need for antiskating exists, as well as some of the more difficult tracks to track. The ones on the other side are a little more useful, the 3 tracks, on at the beginning of the side, one about in the middle, then the final one at the end. Still yet, I find that using it tends to still result in a little much antiskate. Frankly, I have been moving towards the camp of very little anti skate. There are designs ( VPI has a few) that basically do not have antiskate as many arms do. After fiddling with turntables for several decades, I uisually set it about 3/4 s of a gram on my Shure V15vxmr, which tracks at just slightly under 1.25 grams.
Trust you ears on music you are familiar with...you'll probably start using less.
Carefully watch your stylus touch down on the spinning LP. Stare fixedly at the cantilever and observe for any "flexing" to the side upon touchdown. It shouldn't do that. The test record is an interesting tool, but I find the antiskate part to be of the least use. Far better are the tracks measuring resonances in matching cartridges to tonearms. I think that album should have a more in depth explanation on the us of it in setting antiskating. When I first got it, I noticed aftersetting the antiskate to track as many of the torture tracks w/o buzzing as possible, I noticed I had the antiskate set far above the "recommended setting". But something was never quite right, image skewed, etc. setting it to match the tracking weight improved some, continued to improve until I got down to around 3/4 grams. Hopefully your not setting it to track the torture tests as good as possible.

Regards, Russellc

OK, I understand.
So, will playing a groveless record help you to check antiskating in any degree at all? I don't think I can find any test records available locally (in Canada) no matter how hard I look.
Also, when you get a test record and it just so happens that your antiskating is off, won't that cause your cartridge to mis-track and consequently damage your test groove thus rendering it useless?
Which would mean that you have to start with a correct setting to begin with?
BTW, I'm really asking these questions to learn, not to just argue, I swear.
Kris
I wouldn't obsess over it. Just set a little bit of antiskate and forget it, then fiddle with it after having listened a while. the test tracks on the Hi Fi test record are insane, you can see the excessive modulations looking at them. I have certainly never seen an album that wild! If it is set just enough to pull ever so slightly it is probably enough. Fine tune by ear. I know this sounds over simplified, but after obsessing over it and getting less than optimal results for years, this is how I finally do it. Just my take.

Russellc

"Frankly, I have been moving towards the camp of very little anti skate."

same also..
never did understand how a spinning record would exert the same centrepetal force as downforce on a cartridge ? :scratch2:
rega seem to suggest slightly less antiskate than downforce witht heir rb300 arm and i tend to do that with my non rega deck also..
makes the stylus 'sit' better without any noticable sideways skew which i presume (hope ?) is best for information retrieval and less record wear ? :scratch2:
would be interested if anyone else had more scientific light to shed on this.. :thmbsp:

never did understand how a spinning record would exert the same centrepetal force as downforce on a cartridge ? :scratch2:

The anti-skating force needed increases as the tracking force is increased, so the manufacturers do give you a scale that corresponds to the grams of tracking force. But that does not mean the the actual anti-skating force applied to the stylus is the same as the tracking force. I have not measured it but I would expect it to be well under a gram at typical settings.

thanks for your explanation :thmbsp: ..i always presumed the antiskate force was 'measured' in grams :D ..i learn something new every day! :)

To properly use the test record you will need a scope. When the cartridge mis-tracks on the test band it may evenly mis-track on both channels. Increasing the tracking force or changing the arm height or cartridge mounting position can stop the mis-tracking.
If one channel mis-tracks before the other adjusting the anti skate up or down may eliminate the distortion. If you use no anti skate and one side mis-tracks which is normal, this will be the same side that breaks up on the most dynamic passages of your records. When this occurs the stylus will cause permanent grove damage.
If you just run a higher tracking force you will not need any anti-skate. Your records and stylus will have a much shorter life than having the anti-skate set properly though. Many cartridges will not tolerate high tracking forces so once again anti-skate is the solution. After setting up thousands of turntables over the years I know anti-skate works but i am not sure how many shops are equipped to adjust this properly now a days.

Ron-C