Unfortunately that Audio Engineering Department is long gone and forgotten.
There is probably a cardboard box gathering dust in somebody's attic.
If I look over their site they sure seem to have their '70s no-nonsense technical approach replaced by the Elven that forge the Magic Mithril in the Moonlight.
Unfortunately, I've typed out all of the relevant part of the chapter that Alexandrovich wrote, from a book that includes everything from fundamental electronics to room acoustics. Later editions truncated even this, AFAIK. He summarized work that he was personally involved with, but gives no references (most interesting would be the "was experimentally shown" bit) and his number of 480F for vinyl melting point has been challenged here. And, he doesn't really say that melting temperature is reached, rather "it has been suggested".
No longer really sure that "melting" is even interesting in this discussion. What does it even mean in a plastic/elastic/complex mixture? Your original paper talked about real, measurable things - pressure, deformation, moving parts - with zero hand-waving. When we talk about temperature, heat transfer, melting, we're waving so much it feels like we're trying to get a cab in a very bad part of town. Fun though, so Thanks!
All good fortune,
Chris
Did a lot of reading trying to find extra input.
One one hand I found figures of about 1mW to several mW energy generated by friction while playing an LP, so this conforms with the calculations made here.
There where also friction coefficients mentioned for different versions of PVC between 0.1 and 0.5, but let's assume Vinylite is optimized for low friction.
Then I came across a temp measurement that van den Hull was said to have made on his cartridges, thereby finding 60C for the tip.
Don't know what the conditions were, 33 1/3rpm or 78rpm, outer or inner side, so still quite vague.
When this had been measured at 33 1/3 rpm, what temp does the tip then get on a 78 rpm record, twice as much ?
Anyhow there are also references made to 1000C, which is insane because at 700C the diamond tip will start oxidizing, but long before the glued bonding to the cantilever will break down.
https://en.wikipedia.org/wiki/Material_properties_of_diamond
But for the sake of having investigated everything, let's try to make a calculation what effect a 60C stylus could have on the groove.
I'll take a contact relative large contact area of 3u * 10u from tip to groove wall, and further assume a heat penetration dept of 10u, because PVC is a very bad heat conductor and the time to transfer heat on a turning record is short, so these assumptions are just made to get some feelings.
Since heat transfer is k*A/L with k the thermal conductivity, A the surface and L the distance, we have 0.15 * 30e-12 / 10e-6 = 0.45e-6 Watt/Kelvin
Multiplying this with the (60C minus 25C) = 35 Kelvin temp difference results in a heat transfer of 16 microWatt or just ca. 1/1000 of the heat generated in the Tip, with this 60C tip temp assumption!
IMO it makes no sense to investigate this even further because these values are ridiculously low.
So I would like to state that temp rise of the groove wall because of friction can be taken from the list of possible contributors to reduce friction.
Hans
One one hand I found figures of about 1mW to several mW energy generated by friction while playing an LP, so this conforms with the calculations made here.
There where also friction coefficients mentioned for different versions of PVC between 0.1 and 0.5, but let's assume Vinylite is optimized for low friction.
Then I came across a temp measurement that van den Hull was said to have made on his cartridges, thereby finding 60C for the tip.
Don't know what the conditions were, 33 1/3rpm or 78rpm, outer or inner side, so still quite vague.
When this had been measured at 33 1/3 rpm, what temp does the tip then get on a 78 rpm record, twice as much ?
Anyhow there are also references made to 1000C, which is insane because at 700C the diamond tip will start oxidizing, but long before the glued bonding to the cantilever will break down.
https://en.wikipedia.org/wiki/Material_properties_of_diamond
But for the sake of having investigated everything, let's try to make a calculation what effect a 60C stylus could have on the groove.
I'll take a contact relative large contact area of 3u * 10u from tip to groove wall, and further assume a heat penetration dept of 10u, because PVC is a very bad heat conductor and the time to transfer heat on a turning record is short, so these assumptions are just made to get some feelings.
Since heat transfer is k*A/L with k the thermal conductivity, A the surface and L the distance, we have 0.15 * 30e-12 / 10e-6 = 0.45e-6 Watt/Kelvin
Multiplying this with the (60C minus 25C) = 35 Kelvin temp difference results in a heat transfer of 16 microWatt or just ca. 1/1000 of the heat generated in the Tip, with this 60C tip temp assumption!
IMO it makes no sense to investigate this even further because these values are ridiculously low.
So I would like to state that temp rise of the groove wall because of friction can be taken from the list of possible contributors to reduce friction.
Hans
When we can agree on the above, then the groove damage on the Stanton picture cannot be caused by cooling.
What was the fluid that was used, just water seems to be wrong and at least 50% isoppropanol has to be added because water gets pushed off by vinyl causing small air bubbles.
And could it be the stylus force was too low, etc,etc.
Hans
What was the fluid that was used, just water seems to be wrong and at least 50% isoppropanol has to be added because water gets pushed off by vinyl causing small air bubbles.
And could it be the stylus force was too low, etc,etc.
Hans
What about the following test to finally close the Vinyl's temp rise because of friction.
Spray an LP with a mist of an water and isopropanol mixture an play the LP.
Then see how long it finally takes before the LP is dry by evaporation.
Now take a second LP and spray it the same way as the first one.
Let it play for the same amount of minutes as the first one but now with the Cart in the air.
Measure how long it takes before this LP is dry.
When substantial amounts of energy are generated while playing the LP, the first LP must dry substantially quicker than the second one.
Hans
Spray an LP with a mist of an water and isopropanol mixture an play the LP.
Then see how long it finally takes before the LP is dry by evaporation.
Now take a second LP and spray it the same way as the first one.
Let it play for the same amount of minutes as the first one but now with the Cart in the air.
Measure how long it takes before this LP is dry.
When substantial amounts of energy are generated while playing the LP, the first LP must dry substantially quicker than the second one.
Hans
Hi all.
Some 25 years ago I had a look with a B&W IR camera (FLIR) The field of view was some 15° and some 0.5m min focus distance. If there was a 5 to 10d Celcius spot temperature increase , there would have register on the screen image but it didn't (dry play).
Today, IR cameras have much more technical capabilities and they are much cheaper.
If someone has access to one of those, please notice that with the stylus on the non rotating vinyl, he has to do a manual correction for difference in emissivity/reflectivity btn the stylus and vinyl while in thermal equilibrium.
Only after that essential adjustment he should test the stylus on the rotating vinyl.
George
Some 25 years ago I had a look with a B&W IR camera (FLIR) The field of view was some 15° and some 0.5m min focus distance. If there was a 5 to 10d Celcius spot temperature increase , there would have register on the screen image but it didn't (dry play).
Today, IR cameras have much more technical capabilities and they are much cheaper.
If someone has access to one of those, please notice that with the stylus on the non rotating vinyl, he has to do a manual correction for difference in emissivity/reflectivity btn the stylus and vinyl while in thermal equilibrium.
Only after that essential adjustment he should test the stylus on the rotating vinyl.
George
There is the Stanton picture on one side and there is patent 5.389.281 from USPTO describing a composition for cleaning LP’s.
In the patent is mentioned that treated and non treated LP’s were played 200 times.
Guess what, the untreated LP’s had loss of HF and sounded scratchy while the treated ones had hardly any signs of wear. Same differences were also visible under an electron microscope.
Unfortunetly no images.
This subject is a pot of worms
Hans
In the patent is mentioned that treated and non treated LP’s were played 200 times.
Guess what, the untreated LP’s had loss of HF and sounded scratchy while the treated ones had hardly any signs of wear. Same differences were also visible under an electron microscope.
Unfortunetly no images.
This subject is a pot of worms
Hans
I have discussed as a layman, Styli form in the past, and have been made aware some are shaped to work more efficiently as the part producing a modulation velocity within the groove, which as a bespoke styli form, should make it more effective/correct at relaying embedded information than some other forms.
Other Styli are formed to decrease friction within the groove, as a result of the contact surfaces.
All Styli Forms, from the earliest used to the later shaping are all equally effective at creating a modulation that produces a very good sonic quality.
Styli Forms that are parallel designed to make/maintain contact deeper within the groove than a conical form, are usually in the sector where less friction is a resulting trait, it will most likely depend on the contact between surfaces that are resulting from the styli form selected.
Later learning has identified that certain Brands offer a Styli that is a Super Polished product and can be a 'upgraded variant' of a styli form that has been successful in use for the Brand.
My inquisitiveness asks' how much is a Super Polished variant able to contribute to impacting on a reduced drag, or modulation velocity, or even a reduced operational temperature over the more common and longer in use versions?
From a listening stand point, I have been able to be demo'd on the same TT > TA > Headshell and System, very similar in design Cart's with a variance of Styli in used. The Ogura Vital is a form that I find is satisfying my requirements, I would not state it has an attraction that is only because of the Styli contact area belonging to the design, I'm feeling confident in suggesting, the R&D made other discoveries as well, and in the combined effect, there is proving to be an attraction for some who are the end users.
Other Styli are formed to decrease friction within the groove, as a result of the contact surfaces.
All Styli Forms, from the earliest used to the later shaping are all equally effective at creating a modulation that produces a very good sonic quality.
Styli Forms that are parallel designed to make/maintain contact deeper within the groove than a conical form, are usually in the sector where less friction is a resulting trait, it will most likely depend on the contact between surfaces that are resulting from the styli form selected.
Later learning has identified that certain Brands offer a Styli that is a Super Polished product and can be a 'upgraded variant' of a styli form that has been successful in use for the Brand.
My inquisitiveness asks' how much is a Super Polished variant able to contribute to impacting on a reduced drag, or modulation velocity, or even a reduced operational temperature over the more common and longer in use versions?
From a listening stand point, I have been able to be demo'd on the same TT > TA > Headshell and System, very similar in design Cart's with a variance of Styli in used. The Ogura Vital is a form that I find is satisfying my requirements, I would not state it has an attraction that is only because of the Styli contact area belonging to the design, I'm feeling confident in suggesting, the R&D made other discoveries as well, and in the combined effect, there is proving to be an attraction for some who are the end users.
Maybe I wasn't clear in posting #50, but it concerned wet playing with their patented fluid, just like Stanton did with an unknown fluid.
However, I failed to find in the Patent under which name the product is offered to the market.
I will enhance posting #1 with some of the facts collected over the past few days keeping everything together in a compact way.
Hans
However, I failed to find in the Patent under which name the product is offered to the market.
I will enhance posting #1 with some of the facts collected over the past few days keeping everything together in a compact way.
Hans
Which leaves us with the effects of the same forces causing the deformation, a "static" force of .707 x vertical tracking force, and a "dynamic" force varying with modulation, which can approach but not exceed the "static" force? Calculated from stylus effective moving mass x accelleration.
All good fortune,
Chris
Last edited:
I've not seen anyone mention it, so I'll ask what may be a very dumb Q. How much of the energy is being transferred to the cantilever which is either moving the magnet or coil to produce the signal? The signal is a few mV, so not much there, but I imagine the losses are pretty high from moving the mass of the magnet or coil and cantilever.
LAST Record Preservative does some VooDoo to the surface and is long evaporated before play, so not directly comparable to wet play. BTW, it actually does something - can't say if it's universally positive, but it does something noticeable (even to me, who can no longer hear 6KHz). I use StyLAST religiously, so you can judge my objectivity from that.
All good fortune,
Chris
All good fortune,
Chris
Here's a perspective on how I interpret your question: Imagine that a microgroove (LP) record and its playback mechanism were scaled up so that the groove were about 3 feet or a Meter deep, so you could sit on the land and dangle your feet into the groove. At this scale the smallest stylus made is 20 feet tall and is mounted on a cantilever the length of a football field.
All of the energy in the system is provided by the groove wall, in turn provided by the platter, etc. Of this energy some is lost to friction, but a much greater amount is dissipated in deforming the groove wall and in the "donut" cantilever suspension/pivot bearing's designed dissipation. This whole discussion is finally about the relative proportions of these dissipative elements. So, a good question!
All good fortune,
Chris