Zany measurements and theories


I have to say that I do accept stylus drag exists, however where on earth do people get:
1. Stylus getting to temperatures that can melt vinyl - if so we'd never play out records more than once
2. Our records get hit with tons of pressure - if so why are none of my records smashed
parrotbee
"1. Stylus getting to temperatures that can melt vinyl - if so we'd never play out records more than once"

That's true. I'll look and see if I can find something to post for you. As long as you're TT is set up properly, the heat doesn't destroy the record, but you should let the record cool down for a while before you play it again.
Given the high pressure at the contact point and the small size of the stylus, I would not be surprised if it does get hot. But, so what? It is in contact with any given part of the groove for so short a time there cannot be any significant transfer of heat. I don't know if there is some very short-term and very local melting at the point of contact. In any case heat is NOT an issue as to whether a record can be played again shortly after a playing.

What MAY be an issue is elastic deformation. When the record is played, the extreme pressure does cause the groove to temporarily deform. Like most elastic material when it is in such stretched state, the vinyl is also more brittle and is less able to further deform without tearing. The issue has to do with how long does it take for the groove to snap back to its original state.

It is evident for anyone who has repeatedly played the same track or part of a track that the groove snaps back to substantially the original state fast enough that one does not hear obvious distortion from a second play. Whether it has completely snapped back, and if not, whether the slight remaining deformation results in damage during a subsequent play is the issue. I read somewhere a long time a go that the record does not fully snap back for several hours. But, I don't think that records are so delicate and are being played so close to the margin for damage that it really matters, except perhaps, as an academic concern.
I remember reading years ago, that because of the heat generated and vibration created as a stylus tracks a groove.
That you should only play that LP once in a 24 hour period to allow it to "rest" from the heat and vibration. Now that seemed pretty far fetched to me that a hard vinyl groove would actually vibrate. But on some microscopic level maybe it does? But in a cautionary procedure, I seldom ever play a record more than once in a day. I guess it shows how susceptible I am to the power of suggestion, doesn't it....
Records have been around for an amazingly long time and continue to sound good so I wouldn't lose any sleep over them not being indestructible.

If you wear one out and still must listen, time for a new copy. Nothing lasts forever.