[*Scotty*]

More information on vinyl replay from Handbook for Sound Engineers (1988)
Howard W. Sams & Co. Audio Library
 
 
 
 
Scotty

[pansixt]

Scotty-I transferred this reply from the cleaning secrets topic.

Okay, they are saying with the liquid applied to the vinyl surface, there is no melt from the high temps, then there is minimal to no wear on the diamond or the vinyl?

What is the scouring? That sounds like a bad thing. I'm not sure what I am looking at in the image of the scouring of the groove wall.

James

[*Scotty*]

The picture shows the gouging and removal of the vinyl that occurs when a very thin layer of the vinyl can't melt at the point of contact. If it can't melt and accommodate the passage of the stylus accelerated wear results.
Scotty

[Wayner]

I tried it and found no benefit from the water presence. However, I think I have an issue with the "findings" of the research paper, or at least they didn't address the water's ability to cool and act as a lubricant.

That is why machinists use water when machining metal, to keep the working tool cool and to lubricate the cutting.

At any rate, while it was fun to try, I'll run mine dry.

Wayner

[JoshK]

So records or not like women then?

[BaMorin]

The force numbers they use in this report are misleading at best. Actually close to fraudulent. The forces they give are based upon static friction due to static weight. .7gram per side(each groove wall) from a static load of 1.4gr of tracking force.  That number is correct, except the groove does not see static forces during play. Kenetic friction is always lower than static friction. The kenetic friction forces will vary depending upon frequency.
Low frequency = higher kenetic friction, yet still lower than static. High frequncy = lower kenetic friction.
A phenomena occurs when friction goes from static to kenetic called moment of motion This is not moment of inertia. During that "moment" from static to kenetic, energy drops 90deg in relation to the static (fiction) vector. 

[*Scotty*]

From Handbook for Sound Engineers
[ The vertical tracking force applied to the stylus is divided between the two walls. Each wall is experiencing force that is equal to the total vertical force times the cosine of 45 degrees or .707
(Fig. 23-117)
 
 For instance if the vertical tracking force (VTF) is 1g,then each groove wall will experience a force of .7g. This wedge effect plays an important role in understanding the dynamic behavior of of the stylus in a compliant groove and its effect on electrical separation between the channels.]

I run an AT 440ML and I use a VTF of 1.4 grams which when multiplied times .707 yields a .9898 gram force on the groove walls. This is 30% higher than the above cited example.
 Many moving coils track at 1.8g. to 2.2g. VTF.  In the case of the 2.2g. VTF  this would yield a  force on each groove wall of 1.5554g. which is more than double the force of a 1 gram VTF.
If anything the 1VTF in the example was overly conservative and was obviously chosen for how neatly the math works out. In the real world the forces on the groove wall can easily be more than twice as high.
 The key point here is that the forces exerted on the groove walls are sufficient to generate temperatures above the melting point of vinyl which is 480 degrees F.. The micro-melting at the point where the stylus contacts the groove wall is also a critical factor in reducing record wear.
 When a coolant is used on the surface of the vinyl record and melting is inhibited the stylus starts to behave like a cutting tool on lathe instead of device for recovering information on a record.
 Scotty
 

[Mitsuman]

The force numbers they use in this report are misleading at best. Actually close to fraudulent. The forces they give are based upon static friction due to static weight. .7gram per side(each groove wall) from a static load of 1.4gr of tracking force.  That number is correct, except the groove does not see static forces during play. Kenetic friction is always lower than static friction. The kenetic friction forces will vary depending upon frequency.
Low frequency = higher kenetic friction, yet still lower than static. High frequncy = lower kenetic friction.
A phenomena occurs when friction goes from static to kenetic called moment of motion This is not moment of inertia. During that "moment" from static to kenetic, energy drops 90deg in relation to the static (fiction) vector.

Marc, have you been drinking again? 



J/K

[Elizabeth]

It has been a 'story' since the 1960's that playing Lps wet will ruin them.
I tried it back then to test it. And for the first play 'wet' they sounded fine. But afterwards sounded much worse.
So I stopped doing it.

Every once in awhile this idea pops up. It never goes anywhere.
I guess the people willing to try it.. then checking the Lp later just kills it.
So since it has been floating around for 50 years.... and it never gets off the ground with anyone as more than a curiousity.. (and an experiment not to be repeated)
Guess that makes it clear it is a bad idea.

[BaMorin]

Marc, have you been drinking again? 



J/K

No, but at times i wish i was.     and I'll address why in my next post on this subject.

[Wayner]

Anyone that tried the trick, as I did yesterday (never hearing of it before, too sheltered of a life), would soon realize that the water's adhesion would prevent the entire record from becoming wet. You simply couldn't get enough water on the surface.

So, for the most part, the stylus ran thru rather dry areas on the record surface. My initial suspicion is that there may be another cause for any groove damage, or it is in addition to the cause. That may be stylus groove chatter, because the stylus is hydroplaning in the grooves, and hitting the modulations in an uncontrolled hit an miss.  Like tracking with too little VTF.

The reason I say this is that hydraulics are very powerful, and I believe would prevent proper contact in the grooves, where water is present.

My partial theory, anywho.

Wayner

[BaMorin]

From Handbook for Sound Engineers
[ The vertical tracking force applied to the stylus is divided between the two walls. Each wall is experiencing force that is equal to the total vertical force times the cosine of 45 degrees or .707
(Fig. 23-117)
 
 For instance if the vertical tracking force (VTF) is 1g,then each groove wall will experience a force of .7g. This wedge effect plays an important role in understanding the dynamic behavior of of the stylus in a compliant groove and its effect on electrical separation between the channels.]

I run an AT 440ML and I use a VTF of 1.4 grams which when multiplied times .707 yields a .9898 gram force on the groove walls. This is 30% higher than the above cited example.
 Many moving coils track at 1.8g. to 2.2g. VTF.  In the case of the 2.2g. VTF  this would yield a  force on each groove wall of 1.5554g. which is more than double the force of a 1 gram VTF.
If anything the 1VTF in the example was overly conservative and was obviously chosen for how neatly the math works out. In the real world the forces on the groove wall can easily be more than twice as high.
 The key point here is that the forces exerted on the groove walls are sufficient to generate temperatures above the melting point of vinyl which is 480 degrees F.. The micro-melting at the point where the stylus contacts the groove wall is also a critical factor in reducing record wear.
 When a coolant is used on the surface of the vinyl record and melting is inhibited the stylus starts to behave like a cutting tool on lathe instead of device for recovering information on a record.
 Scotty

The static down force, and friction are not the same thing.  If you should set your stylus down in an un-moving run-out groove for a day you will find a dent where it sat. you will not find that indention from allowing the stylus to play the run-out groove.  Heat is due to friction.  There is very little friction in a moving groove. The friction is kinetic not static. The values in that paper refer to only static.
If the two surfaces are of equal material of equal roughness kinetic friction is only 40% of static friction.
The paper gives no information on the friction coefficient of the diamond surface nor the vinyl surface. It only gives static load. Those two coefficents must be averaged, and then the 40% rule applies. This is high school physics guys.

[*Scotty*]

BaMorin, is it your contention via this argument that it is okay to play your records wet?
Apparently there is an adequate amount of "Factor X" to cause melting at the point of contact under the dynamic conditions that exist during playback.
 I strongly suspect that the reason that the scope of the treatment of this subject in the Sams book was limited to static conditions only is because an in depth analysis of the factors in play under dynamic conditions is not practical or possible. For example imagine the increase in force against the groove walls due to instantaneous G loading as a result of the lateral accelerations encountered while tracing the undulating groove.
Scotty

[BaMorin]

BaMorin, is it your contention via this argument that it is okay to play your records wet?
Apparently there is an adequate amount of "Factor X" to cause melting at the point of contact under the dynamic conditions that exist during playback.
 I strongly suspect that the reason that the scope of the treatment of this subject in the Sams book was limited to static conditions only is because an in depth analysis of the factors in play under dynamic conditions is not practical or possible. For example imagine the increase in force against the groove walls due to instantaneous G loading as a result of the lateral accelerations encountered while tracing the undulating groove.
Scotty

No, not at all. I think the idea of wet playing is silly. I wouldn't run track if i had to run in 4" of water vs the guy running on a dry track. The other issue of wet playing I find silly is water is corrosive, and my cantilever is aluminum. It's also a tube that retains stress. Stress and a corrosive environment leads to stress corrosion cracking.  I think DaveyW has a photo of a cantilever that has ruptured do to stress corrosion.  I do not believe there are any "X factors" that would suggest that vinyl melts during playback.
The paper shows what pressure the stylus is exerting on a static surface and then tries to give the implication by showing modulation on one channel and its load on the other channel. That won't be the case under kenetic conditions. The paper confuses load and friction. Heat from friction is caused by the disturbance of the electrons in both surfaces.
I believe as you posulate that the damage to the groove walls is in fact do to impact loading of the stylus as it slams it's way down the modulated groove. The loading forces there would be quite high.......but that is not do to friction nor heat from friction.

[*Scotty*]

From what I read it appears that it was experimentally verified that melting does indeed take place at the point of contact during playback which prompted the hypothesis that the temperature at the point of contact must be above the melting point of vinyl which is 480 degrees. Friction must be the culprit here in as much as the vinyl doesn't melt when the cartridge is just sitting still in the groove.
Scotty
 

[neobop]

A couple of yrs ago this came up on VE. The vinyl melting thing was supposedly debunked. I can't help out with the proof but you can find it on their forum somewhere. VDH is said to have measured temps at 160 C. That would = 320 F. Not enough to melt vinyl and nobody could find the published measurement. Because the groove is moving, even with limited contact heat just doesn't build up like it does playing a metal master. Diamond is a good conductor of heat and vinyl is very different from metal.

There's someone else there that plays records wet, and claims no problems. I believe he mists the surface rather than make puddles. I'm just telling you about this, not arguing one way or the other. I play records dry. Sometimes I use stylast but most times I don't bother.
neo

[*Scotty*]

It would interesting to attempt to measure the temperature with an non-contact infrared thermometer. The melting would be easy too see with modern video techniques the temperature may be much more difficult to measure because the contact area is under the diamond.
 Given that the vinyl almost immediately re-freezes and is therefore less than the melting point on the trailing side of the diamond I wouldn't be surprised at some experimental error creeping into the temperature measurement.
Scotty

[BaMorin]

It would interesting to attempt to measure the temperature with an non-contact infrared thermometer. The melting would be easy too see with modern video techniques the temperature may be much more difficult to measure because the contact area is under the diamond.
 Given that the vinyl almost immediately re-freezes and is therefore less than the melting point on the trailing side of the diamond I wouldn't be surprised at some experimental error creeping into the temperature measurement.
Scotty

simple experiment.........take a piece of a broken record, melt it and then see how long it takes to get hard again. I ain't buying it immediatly re-freezes. I ain't buying it melts in the first place. The photos show impact damage. The pseudo-science claims melting due to friction, yet no friction numbers are given. Only load factors. I can run a car into a tree to show load factor damage......friction wouldn't have a thing to do with it.

[cheap-Jack]

Hi.

simple experiment.........take a piece of a broken record, melt it and then see how long it takes to get hard again. I ain't buying it immediatly re-freezes. I ain't buying it melts in the first place. The photos show impact damage. The pseudo-science claims melting due to friction, yet no friction numbers are given. Only load factors. I can run a car into a tree to show load factor damage......friction wouldn't have a thing to do with it.

Bingo. It's "pseudo-science" to its best if not a fraud.

My years of WET play on my old old LPs recycled from thrift stores has proven so. They ALL sound not a bit worse if not better. My very picky ears do not lie to me, period.

My keen queston is: Why so many keep in alleging WET play is bad? Any hidden commerical or political agenda behind all those negative allegation & accusation ????

My years experience of WET play proves the opposite:- No damage to my cartridge, nor to ALL my LPs wet played since day one, & the music which I
concern most sounds so much more fluid, vivid & muscial  with wet play over dry play.

Like every vinyl fan, I started with dry play but the tracking noises drove me nut. Then I tried WET play with huge skeptism like everybody else. I was stunted by the imrpovement:- the tracking noise is gone & the music sounds so much better - from Pavarotti to Tom Jones.

From that moment on, I've stuck with WET play & I just can't turn back to dry play. MY picky ears won't allow me to do so.

May I plead whoever dry play fans try wet play before starting condemning it basing on some pseudo-science ever so published.

c-J
"If the facts don't fit the theory, change the facts." quoted Albert Einstein.

[Quiet Earth]

I never heard of wet playing a record until reading this thread.