Mistracking LPs

[evetsfrance]

Is there a reason why used LP's seem to mistrack more at the start?
Is it because the vinyl is going faster past the stylus and so wears more?
Is this actually a known phenomenon or just me?
The cartridge is very carefully alingned.
Steve

[kevinahcc20]

The opportunity for damage to LP grooves is much higher at the outer periphery of the record due to careless tonearm handling, miscues, and inadequate damping in the cueing mechanism. Once the stylus is in the groove and the listener is back in his/her chair the risks go down considerably.

[kevinkr]

Do you mean skipping or actual mis-tracking? The two are quite different, and mis-tracking generally becomes a larger problem as the velocity decreases towards the inner grooves and the wavelengths of high frequency material become short - approaching in some cases the size of the stylus contact area.. This is usually characterized by badly distorted and congested sounding high frequencies..

[evetsfrance]

Originally Posted by kevinkr

Do you mean skipping or actual mis-tracking? The two are quite different, and mis-tracking generally becomes a larger problem as the velocity decreases towards the inner grooves and the wavelengths of high frequency material become short - approaching in some cases the size of the stylus contact area.. This is usually characterized by badly distorted and congested sounding high frequencies..

Sorry,I can't be more exact - I mean the sound is distorted as if the stylus needs cleaning. I call that mistracking but I'm probably woefully inaccurate.I would have expected things to get worse towards the inner part for just the reason you explain but things seem to be bad at the start, much better in the middle and not as good towards the centre. I'm sure I've got the cart properly set up.
Steve

[Conrad Hoffman]

Sure, the forces dragging the arm towards center are greater the further away from center you get. Anti-skating devices help there but are always compromises. There's also a slight bulge on the outer edge of many records and the surface at the beginning can be slightly "downhill". The tonearm wires could be pulling is slightly at the outer edge, depending on how they're biased. All this stuff conspires to cause skipping if there's any groove damage or scratches near the edge. There's also an inertia effect. When the stylus touches down, it usually doesn't land directly in a groove. The arm then moves inward until the stylus "catches" a groove. Without adequate anti-skating forces, the arm may be moving faster than the spiral of the lead-in groove. Because the arm has mass and inertia, it can easily keep right on going and pop out of said groove, to hopefully grab the next one. Warps are usually worse near the outer edge, making everything else described even more of an issue.

Saw your last post- that sounds more like mistracking. Maybe the stylus really is dirty and needs a wet cleaning. Tar like deposits can build up and be near impossible to remove. Maybe the alignment isn't as good as you think. Go to my website and try the arc template generator- be sure to read the read-me file! Finally, maybe the stylus is damaged.

[evetsfrance]

Originally Posted by Conrad Hoffman

Sure, the forces dragging the arm towards center are greater the further away from center you get. Anti-skating devices help there but are always compromises. There's also a slight bulge on the outer edge of many records and the surface at the beginning can be slightly "downhill". The tonearm wires could be pulling is slightly at the outer edge, depending on how they're biased. All this stuff conspires to cause skipping if there's any groove damage or scratches near the edge. There's also an inertia effect. When the stylus touches down, it usually doesn't land directly in a groove. The arm then moves inward until the stylus "catches" a groove. Without adequate anti-skating forces, the arm may be moving faster than the spiral of the lead-in groove. Because the arm has mass and inertia, it can easily keep right on going and pop out of said groove, to hopefully grab the next one. Warps are usually worse near the outer edge, making everything else described even more of an issue.

Saw your last post- that sounds more like mistracking. Maybe the stylus really is dirty and needs a wet cleaning. Tar like deposits can build up and be near impossible to remove. Maybe the alignment isn't as good as you think. Go to my website and try the arc template generator- be sure to read the read-me file! Finally, maybe the stylus is damaged.

Thanks, I'll get your template. Please could you post a link to your website. The cart is a new AT 125 LC run in for about 8 hours. I wet clean it often since I'm using Cillit Bang to clean the records (you don't want to know - or perhaps you do- I've never found anything that removes surface noise and distortion like this but it seems to provoke a rage reaction in vinophiles).

[Swarky]

So the question is : What cleans Cillit Bang deposits off a cartridge tip ?

[indianajo]

I've had some used LP's be so dirty that they fuzzed up the needle in one band, causing massive skating and skipping. If they look horrible I wash them before I play them, but sometimes I get fooled. This month I thought I had a cracked needle diamond, but the reading glasses proved it was just a big ball of fuzz. I have the Shure M97 with a brush, too.
There are occasionally LP's with the hole not punched in the middle. My only record of Buxtehude (bought new from Colombia @ Foley's) is mislocated on the back, wow, wow, wow. Have found a CD of that by Lionel Rogg, now if I just didn't have to spend last month's pension on a tooth, and this month's on a car engine - - -Life, it is too real. Still, occasionally LP's at the charity resale shop for $.50 turn out to be a lightly used bargain, but almost never artists on your top ten list.

[jcx]

warp amplitude can be higher near the outer edge, the acceleration is then worse from the constant angular velocity

[kevinkr]

Originally Posted by jcx

warp amplitude can be higher near the outer edge, the acceleration is then worse from the constant angular velocity

Pretty good test of how well matched your cartridge compliance is to the effective mass of the arm.. Pretty interesting watching a badly under damped response in a mechanical system.. Taken to an extreme the stylus will actually leave the grooves at times, what an interesting sound that makes..

One of the other possibilities where distortion is very high on the first couple of cuts is if the recording was played with a badly worn stylus - the wear will probably be worst where the angular velocity is highest. I do have a few records that exhibit this trait.. It could also be a teen who liked a particular song and played it repeatedly in succession (not a few times, but dozens of times..)