"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. |
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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. |
Out of interest are such actual theories authentic and in fact true?
When we talk of pounds of pressure is made made having iea of context and comparability as to the forces generated in otehr mechanical circumstances - ie this is the force generated by a car in x, y or z circumstances?
I only say this because I find it sometimes hard ti understand things without a comparative example
thanks |
"I only say this because I find it sometimes hard ti understand things without a comparative example"
Why a comparative example? If we are talking about a record melting, why not just get an actual example?
"01-23-15: Theo
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?"
Compared to the stylus, the vinyl that a record is made out of is very soft. If something is going to give due to hardness, it won't be the needle. Also, a phono cart works off of vibration. There has to be some transfer back to the record itself.
More important, though, I promised the OP that I would find him some info on the subject. Your post triggered my memory as to where I read it first. I remembered it was years ago too, in a book called Good Sound by Laura Dearborn. Either late 80's or early 90's. I don't have the book anymore, but I'm pretty sure a lot of people posting here on Audiogon here still do. People reference it all the time. So if anyone that has the book can look the info up to confirm that the vinyl melts when played.
I also read it in another publication. I'm pretty sure it was in the Audio Perfectionist Journal. The article was an interview with Brooks Berdan. He's famous for turntable setup and repair. Unfortunately, I don't have that article either, and I doubt anyone else will either. APJ was pretty rare.
One last thing in response to the OP. I don't think the issue of melting was put into proper perspective. There's no question that there is a lot of heat generated when the needle passes through the record groove. But when some of us says it melts the record, that doesn't mean it liquefies the vinyl. It gets heated up to where it becomes softer. If you play the same record again, without letting it cool, it wares the record out faster, but it still plays and probably sounds the same. Its the kind of thing that builds up over time from abuse. Also, keep in mind that most audiophiles use higher end phono carts that have styluses cut to better conform to the record groove. They dig deeper into the record than a regular consumer grade needle. That combined with the fact that audiophile gear is much more revealing of flaws than standard gear, easily explains why we may pick out such differences, where many others can't. |
I suspect that the vinyl that deflects from friction heat returns quickly to its
original form and is back to room temp before the record is finished playing.
For all this talk about a 24-hour cooling off period, is there any resarch to
verify this--with electron micrographs and temperature measurents with a
cooling-off timetable? No? Then a dogma has once again risen out of worst-
case speculation of a theoretical scenario with no verification. |
Pressure is force/unit of area. For a phono stylus the force is small but the contact area is very, very small. Result, high pressure.
For another example,consider ice skates. Ice occupies more volume that liquid water, hence high pressure lowers the melting point (Le Chatelier's principle). Since the contact area of the skate is small, the pressure is high. High enough to melt the ice temporarily and lubricate the skate. |
"Then a dogma has once again risen out of worst-
case speculation of a theoretical scenario with no verification."
It's not speculation. The contact point does get very hot. I did list 2 publications in my last post that dealt with this topic.
If you want some type of scientific explanation, look at it this way: How could there not be heat generated when playing a record. There's friction. I has to heat up. |
Most estimates for stylus surface temps range between 300-
500 degrees(F). The temperature of your record will be
at(or close to) room temperature, except at the point of
contact with the stylus. Much will depend on VTF and
RPM(higher numbers there=higher temps). You're only talking
about milliseconds of contact, between the sylus and any
given point in the groove. Maybe a few molecules of vinyl
will be heated and the surrounding vinyl acts as a
heatsink(ice skate example, on a much smaller scale). I've
got a number of test records, that I used in my shoppe, for
setting up turntables. They were, of necessity, played
multiple times, during a setup. They are still as pristine
in function & sound as when I purchased them. Even the very
high velocity, "Tracking Torture Test Tracks." My
favorite demo record tracks, were often played numerous
times, within a few minutes, to compare my various speaker
models to customers. That was in the 80's and I'm still
enjoying those vinyls, with no loss of presentation. |
All of us who play records, at some point, have seen a little buildup of dust on the stylus while a record plays every now and then. I'm not sure what the combustion temperature is of dust, but I think it'd be safe to say that those grooves aren't getting hotter than what it would take for dust to smolder or even ignite. |
From a theoretical standpoint, the real issue here is what Rodman9999 points to; how much heat is actually transferred from the stylus contact point (very small) and the vinyl (which is only in contact with the stylus for what I would venture to guess is milliseconds at a time). Also the elasticity of the vinyl, how that varies with temperature, and it's heat transfer properties.
OTOH, the empirical evidence he presents gives me a high degree of confidence that the interaction of those variables in real-life situations is such that this is a non-issue. Thanks, Rodman. Very important information. |
"OTOH, the empirical evidence he presents gives me a high degree of confidence that the interaction of those variables in real-life situations is such that this is a non-issue. Thanks, Rodman. Very important information.
Swampwalker (System | Threads | Answers | This Thread)"
What empirical evidence? |
The empirical evidence is that no one has reported any ill effects attributable to repeated playing using better quality equipment properly setup.
As a precaution I never play my records because there's no telling what damage dragging a rock on a stick thru a jellified oil compound can inflict. Be afraid, very afraid. |
Empirical evidence(empirical data, sense experience, empirical knowledge or the, "a posteriori") is a source of knowledge acquired by means of observation or experimentation. ie: The second 50% of my last post(my personal experience/observations). Of course; accepting those conclusions would depend on one's confidence in my aural acuity, experience with sound/music and powers of observation. Happy listening! |
Seikosha,
The thing is the highest temperature would be at teh point of contact between the stylus and the record due to friction there and dust tend to accumulate towards the front of teh stylus as it moves through the groove, not down there.
Its an interesting question what the temperature due to friction of a stylus moving through a record grove is but its mostly an academic one I think and not of much consequence, though I have no doubt if there were a way to keep it cooler without other negative effects, that could only be a + from a record wear perspective. |
Good point Mapman,
At the minimum, I'd think that we'd be seeing sparks from random specs of dust in the record if there were any heat of significance being generated at the stylus in the groove.
I think if one had a thermal camera, they could view a record while it's being played and see if any real heat is being generated. |
Yeh...I'm with Rodman on this....
The man has shown over many years that he 'knows his onions'....😎🎼 |
"01-27-15: Onhwy61
The empirical evidence is that no one has reported any ill effects attributable to repeated playing using better quality equipment properly setup."
How do you know that? Its not like there's a hotline where people report this type of thing. One way or another, a record will wear out eventually, just from use, no matter how good the gear or setup is. Best you can do is prolong it from happening. But that's really not the issue here. This discussion is just about whether the record get really hot, and possibly deforms/melts when you play it. If all records do this, to some extent, its considered normal operation.
Honestly, the problem here is really 2 fold. First, I think many people, whether its in this thread, or any of the others, get caught up in the argument and want to win it, as opposed to finding out what the real answer is. For the most part, I think its unintentional, but its a factor none the less. Now, before anyone asks, yes, I have gotten caught up in this type of thing myself. I'm no different than anyone else.
The other problem is that there's not too much current info on anything involving vinyl playback. For the mainstream consumer, its a format that died sometime in the late 80's. But there is some information out there. And every time I see a comment on this issue, by someone that knows audio well, and is an expert on vinyl playback, they all say the same thing. The record gets very hot and/or melting occurs at the point of contact, when you play it. I just happened to see another comment when I was shopping on Needle Doctors web site. He's one of the last, big, well known vinyl experts. This is a direct quote from him pertaining to record care.
"Last, remember that every time you play a record, you are in essence damaging it. On a micro level, the diamond melts the groove as it passes through. The groove will wear down whether you like it or not, so just enjoy your records and do what you can to slow the deterioration. "
Its pretty much the same thing every other TT expert says. Now, I know that someone can argue that he didn't include scientific data or test results that can be verified. So, as far as winning or losing the argument goes, I loose by default. No question about it. So, back to reality, even though I lost the argument, I still can't find an expert in vinyl playback to say anything other than the record melts when you play it. |
01-27-15: Zd542
JohnnyB53: "Then a dogma has once again risen out of worst-
case speculation of a theoretical scenario with no verification."
It's not speculation. The contact point does get very hot. I did list 2 publications in my last post that dealt with this topic.
If you want some type of scientific explanation, look at it this way: How could there not be heat generated when playing a record. There's friction. I has to heat up.
I never denied that it heats up. Of course it does and I've read the articles too. I'm saying that the dogma to cool your records for 24 hours before replay is idle speculation. In fact, it's empirically contradictory. At the very least an LP would be warm to the touch after playing, but it's at the same room temp it was when it started. I've read articles about the vinyl going momentarily soft where the stylus passes. Some of these articles also say that the vinyl at the point of contact immediately cools and returns to its original formation after the stylus passes. Rodman explains very well why some momentary intense heat would not have a lasting effect. The hot spot is tiny and constantly moving. The overwhelming mass of the rest of the record acts as a heat sink so there are no lasting effects. It's been working this way for 67 years. |
There are a number of references cited, in the first post of the following thread: (http://www.vinylengine.com/turntable_forum/viewtopic.php?t=27421) No doubt; there's some interesting reading to be found. Especially the Journal of the Audio Engineering Society and Wireless World papers. |
The empirical evidence I was referring to was Rodman's I've got a number of test records, that I used in my shoppe, for setting up turntables. They were, of necessity, played multiple times, during a setup. They are still as pristine in function & sound as when I purchased them. Even the very high velocity, "Tracking Torture Test Tracks." My
favorite demo record tracks, were often played numerous
times, within a few minutes, to compare my various speaker
models to customers. That was in the 80's and I'm still
enjoying those vinyls, with no loss of presentation. |
"01-27-15: Swampwalker
The empirical evidence I was referring to was Rodman's
I've got a number of test records, that I used in my shoppe, for setting up turntables. They were, of necessity, played multiple times, during a setup. They are still as pristine in function & sound as when I purchased them. Even the very high velocity, "Tracking Torture Test Tracks." My
favorite demo record tracks, were often played numerous
times, within a few minutes, to compare my various speaker
models to customers. That was in the 80's and I'm still
enjoying those vinyls, with no loss of presentation."
I have no doubt that he's telling the truth. I've had similar results myself. I think we lost track here because I was basing my answers on the OP's post. Look at it again.
"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"
That's an extreme view that just doesn't hold up. And the reason that it doesn't hold up is just what is in the quote you reference. He's making it out to be the record will be used only 1 time, and that's just blowing the whole thing way out of proportion. Now, as far as to how long you let the record cool after playing it, the recommendations from most of the experts that I've read or spoken to can range anywhere from 2-24 hours. Given that, we all make up our own best practices as to how long we let our records cool, if any. For me, when breaking in new carts, I've taken records that are in like new condition, and played the same side over and over again (wasn't something out of my collection, just music I didn't like), and didn't notice too big of a difference. A little, but not much. Was the wear due to heat? My best guess would be that it was a factor, but not the only one. But if you guys really want to find out for sure, why don't we split the cost on a really good thermal imaging camera? lol. Then we can argue about something new. What camera do we buy? |
