Inner tracks sound "gritty"

[johnr66]

What causes the inner tacks on my LPs to sound more of a gritty distortion. I installed a new stylus, reset counter weight and check antiskate. I also checked cartridge alignment with the little ruler tool that I put over the center pin and check the cartridge angle at two points.

Granted my turntable is a low end Radio Shack model LAB 310 from the 80's, but it sounds fine in the outer tracks. The most inner track sounds the worst to me.

[d to the g]

Inner groove distortion is most likely due to antiskate setting. Find a record with one 'blank' side (no grooves) and place your cartridge in the middle of the playing surface. Set antiskate by keeping the cartridge from moving.

[steven0356]

Where would you find a record with one of it's sides blank? I am not sure i have seen anything like that

[johnr66]

I have never seen one either, but I think taking a sheet of plexi and making a circle with a hole will work just as well.

[d to the g]

Originally Posted by steven0356

Where would you find a record with one of it's sides blank? I am not sure i have seen anything like that

Single sided 12" dance singles... at least two of which are Derrick Carter records.

[dangus]

I have a test record with a blank area on one side for setting antiskate. I can't remember the name, but it wasn't one of the famous test discs like CBS or Shure. I bought it mostly for that one feature, to set the antiskate on a DIY arm. It came in a molded white styrofoam jacket, which looked a bit like something McDonalds would have sold take-out pizza in, if McDonalds had sold pizzas that were square.

[hotbottle]

I believe it has been shown that setting anti-skate on a blank record was a fallacy, due to a misunderstanding of where the skating force actually comes from. The force is due to the pull of a groove in a direction not directly aligned with the pivot, so a blank record will not generate the same force, because the friction on a blank surface is not the same as when a stylus is sliding along a groove.

Another thing I'll add, is that I never eliminated the inner groove distortion until I got one of the fancier stylus shapes, specifically a "microline" shape. Much better inner groove performance that an eliptical stylus.

[Conrad Hoffman]

Anti-skating won't be right if set on a blank record. For high compliance cartridges try looking at the centering of the stylus when not on a record. Adjust the anti-skate while playing to put the stylus at the same center point as it had in mid air. The same cartridge offset that reduces tracking error to a minimum is also what causes the skating force.

No idea what you might be hearing. Could be cartridge alignment, anti-skating (though I doubt it) or dirty/damaged records (most likely). A huge number of records have groove damage from being played with heavy forces or with bad styli. There's also the basic loss of quality on the inner grooves because the velocity is lower. If you work the numbers, the outer edge of the playing area moves the vinyl under the stylus at about 509.81 mm/second. The inner edge moves the vinyl at a rate of 200.71 mm/second. That means that the same high frequencies at the inner edge have a more spatially compressed waveform and probably lower quality with all but the most refined styli.

CH

[hotbottle]

Originally Posted by Conrad Hoffman

The inner edge moves the vinyl at a rate of 200.71 mm/second. That means that the same high frequencies at the inner edge have a more spatially compressed waveform and probably lower quality with all but the most refined styli.

CH

Which is why the Microline stylus performs better, basically it mistracks less on these 'compressed' waveforms because it fits better due the the line contact.

[Shaun]

Originally Posted by Conrad Hoffman

A huge number of records have groove damage from being played with heavy forces or with bad styli.

Sadly, I must concede that much of my LP collection suffers this problem. I have two copies of Gino Vanelli's Brother to Brother and when I play my favourite track People I Belong To, it is painfully gritty...