78 noise

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Coffee Phil
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Re: 78 noise

Post by Coffee Phil » 13 Jul 2019 18:12

Hi H. callahan,

I may be the person of whom you speak. I still don't believe that the abrasive dust was added to wear the needle rapidly but rather for strength and hardness to stand up to the force of the acoustic sound boxes of the day. The rapid stylus wear was a "side effect". Material science was relatively primitive in the day. Even for the day better approaches could have been had. Edison Diamond discs were played with acoustic soundboxes with diamond styli and the playing surfaces were made of an early polymer with no abrasive material added. While that system had to be more expensive it was quieter.

Phil
H. callahan wrote:
13 Jul 2019 04:19
Bob Dillon wrote:
12 Jul 2019 23:26
Interesting that it appears to show little to no wear. Of course, that is on that particular machine with a new steel needle every play. Might have been interesting to hear the record after the first play on the gramophone, then played on a modern hi-fi turntable. Then hear the 100th play on the gramophone again on a modern turntable for comparison. The results may be more revealing of wear having set in. As one of the commentors in the video noted, alignment is important. Some of those old acoustic phonos made really no provision for proper offset of the reproducer to the record groove wall. The old style Columbia machines with their straight arms are one example of that. The reproducer needs to be in good working order too, with a pliable diaphragm and rubber gaskets, so that the movement of the needle is not restricted, thus reducing unnecessary record wear. Not unlike the suspension on a modern phono cartridge.
I assume that he machine+soundbox used for this test was in fully working condition, otherwise the test might have shown a different result.
When comparing the 1st and the 100st play i can hear very small differences, surface noise has increased and there also is distortion on high frequencies - but in the "shellac-world" the record still is in veeery good condition after a hundret plays, almost like new. We´ve had it in another thread where one person did not belive abrasive materials being in the shellac-mix to shift wear onto the needle, but this test does show that the idea of shifting wear from the record onto the needle can work pretty good.
I think one of the reasons why the record held up that well is that the surface of the groove still was undamaged. When playing a record having grey grooves there usually is more shellac-dust on the needle - so it seems that a shellac will wear faster once the groove is damaged.

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Re: 78 noise

Post by Bob Dillon » 14 Jul 2019 03:01

The abrasive is to make the needle tip conform to the groove dimension of the particular record being played with that needle, thus reducing record wear. I think they had other ways of making shellac records "harder" if they wished.

https://www.antiquephono.org/the-origin ... j-wakeman/

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Re: 78 noise

Post by H. callahan » 14 Jul 2019 11:56

Coffee Phil wrote:
13 Jul 2019 18:12
Hi H. callahan,

I may be the person of whom you speak. I still don't believe that the abrasive dust was added to wear the needle rapidly but rather for strength and hardness to stand up to the force of the acoustic sound boxes of the day. The rapid stylus wear was a "side effect". Material science was relatively primitive in the day. Even for the day better approaches could have been had. Edison Diamond discs were played with acoustic soundboxes with diamond styli and the playing surfaces were made of an early polymer with no abrasive material added. While that system had to be more expensive it was quieter.

Phil
Hi Coffe Phil,

yes could be you but i just forgott the name - and i didn´t wanted to put anyone down so even if i did remember the name i wouldn´t have mentioned it.

I get your idea and yes, a harder surface does wear less than a softer surface. But i see it that way:

If you have a sheet of rubber and drag the tip of a screwdriver with a certain pressure across its surface, the rubber will wear while the tip of the srewdriver won´t wear at all. If you now put some sandpaper onto the rubber, in a way it won´t slip, the rubber still is as soft as before - but the inevitable wear will be shifted onto the screwdriver to some extend.
Now this of course only does work within limits, the pressure the screwdriver is pressed onto the sandpaper must be small enough to not cut through the sandpaper - and the paper of the sandpaper also does protect the rubber to some extend, so one had to glue a thin layer of very fine sand onto the rubber to get a correct test-setup, but i think it does show that you don´t necessarily have to increase hardness of a material to reduce wear, you also can reduce wear of the material by making its surface more abrasive - then some of the wear will be shifted (onto the needle).

I assume that Edison Diamond discs were tracked at fewer VTF, respectively wear faster because diamond is stronger than a polymer. As far as i know the idea of the shellac record was to avoid the phonograph-principle, where a pretty soft material is used for the cylinder while a very strong material is used for the needle/stylus, so all of the inevitable wear goes onto the cylinder.

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Re: 78 noise

Post by Coffee Phil » 14 Jul 2019 18:07

Hi Bob Dillon and H. callahan,

What I would like to see is period technical literature discussing if the goal of putting what is essentially abrasive material into the shellac mixture for the purpose of lapping the stylus to fit the groove. I've heard the story before, but to me it does not pass the "smell test". Granted this was the late 19th and early 20th century but I have to believe that technology existed to grind needles to fit the groove of the record. Edison was able to do this with a diamond stylus. I'll grant that the Edison technology was different but it serves to illustrate that a stylus could be made with the proper shape and smoothness to fit the groove of the record.

One of the articles which Bob Dillon linked showed and advertisement from ~ 1920 with Columbia showing their laminated record. They did not explicitly state, but I get the idea that the "sand" or at least the more abrasive sand was confined to the inner layer. There was also an ad for "rotten stone" which suggested that there was a technology associated with that material.

My am not sure, but I still think the stylus wear from the stone material was an undesirable "side effect".

Phil

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Re: 78 noise

Post by H. callahan » 14 Jul 2019 18:39

I don´t have any, but read in several places that it is supposed to wear down the needle before the needle wears down the groove - and that made sense to me.
I don´t think that adding sand or stone powder would increase hardness of a record a lot. If you mix sand with liquid rubber and let it harden, the result still would be very flexible.

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Re: 78 noise

Post by Bob Dillon » 14 Jul 2019 19:09

Coffee Phil wrote:
14 Jul 2019 18:07
Hi Bob Dillon and H. callahan,

What I would like to see is period technical literature discussing if the goal of putting what is essentially abrasive material into the shellac mixture for the purpose of lapping the stylus to fit the groove. I've heard the story before, but to me it does not pass the "smell test". Granted this was the late 19th and early 20th century but I have to believe that technology existed to grind needles to fit the groove of the record. Edison was able to do this with a diamond stylus. I'll grant that the Edison technology was different but it serves to illustrate that a stylus could be made with the proper shape and smoothness to fit the groove of the record.

The Edison was made for the Edison. Vertically cut discs that had a precise pitch / number of grooves (150) per inch. They were intended to be played with a conical diamond stylus.

The typical steel needle gramophones of all brands played lateral records of all brands that had a varying number of grooves per inch, (around 80 to 100) nominally from 2 mil to 4 mil groove width and varying depth too. There was no way to make one steel needle that was a perfect fit for them all.

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Re: 78 noise

Post by Bob Dillon » 15 Jul 2019 20:08

There was a bit of symbiotic relationship between the steel needle and the shellac record. Say they could have ground needles to precise dimensions to fit grooves perfectly. The tip would have still worn down some by the end of the record. So, lets say they made the needles a perfect fit and a harder grade of steel or some other material like a jewel point. Then the heavy tracking weight of the tonearm and reproducer would have inflicted more wear on the record. Apparently, you can buy jewel point needles that will fit a mechanical phono reproducer. Word around the campfire is you never use them in a wind up gramophone or your records will be ground down in pretty short order.

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Re: 78 noise

Post by Coffee Phil » 16 Jul 2019 07:26

Hi Bob Dillon,

What you said about the different groove width makes sense to me, but still I can’t imagine a steel needle being able to be lapped properly for groove widths from 2 to four mils.

I do have a jewel tipped thumb screw needle in my 78 only mid ‘40s Admiral changer. When I was seeking out the stylus I do remember being cautioned against using it in an old acoustic soundbox.
I’m not sure that I believe the story but it is out there.

Phil

Mrs Ritchie Valens
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Re: 78 noise

Post by Mrs Ritchie Valens » 25 Jul 2019 22:40

Um, everyone's sort of talking over my head here, but isn't it only natural for things just to ware down over time, and use, and age?

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Re: 78 noise

Post by Coffee Phil » 25 Jul 2019 23:43

Hi Mrs Richie Valens,

Yes it is true that things do wear with use. After records became a "mature" technology the value of a stylus made of a hard substance and ground to fit the record groove was understood. Styli were made of osmium which is a hard metal, then jewels which are even harder. Sapphire was common as it is less expensive than diamond yet less hard. When it became practical to make diamonds they became practical as phono styli for common folks.

Now back to the early shellac days. The records were made of shellac with a filler of various materials which was proprietary to the record companies. A good bit of the filler was powered stone which is abrasive and noisy. The purpose of the stone powder is the subject of discussion (argument). I believe it was added for strength in like manner to aggregate in concrete with the abrasive and noisy effects an undesirable side effect. Many believe that the abrasive effect was intentional for the purpose of lapping the steel needle to the shape of the groove. To me the problem with that notion is that steel needles were to be changed after one or two, at most, plays. If the notion of the abrasive record lapping the needle is so why then do not the needles continue to get better and need replacement only when they get unacceptably short? I am still reading on this and would like to find period literature on the subject.

Phil

Mrs Ritchie Valens wrote:
25 Jul 2019 22:40
Um, everyone's sort of talking over my head here, but isn't it only natural for things just to ware down over time, and use, and age?

Mrs Ritchie Valens
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Re: 78 noise

Post by Mrs Ritchie Valens » 25 Jul 2019 23:52

Hmmmm, yeah...

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Re: 78 noise

Post by Bob Dillon » 26 Jul 2019 01:37

Coffee Phil wrote:
25 Jul 2019 23:43
Many believe that the abrasive effect was intentional for the purpose of lapping the steel needle to the shape of the groove. To me the problem with that notion is that steel needles were to be changed after one or two, at most, plays. If the notion of the abrasive record lapping the needle is so why then do not the needles continue to get better and need replacement only when they get unacceptably short? I am still reading on this and would like to find period literature on the subject.

It's not so much the needles getting short. It's wear flats on the needle turning them into a cutting tool. The needle starts out with a spherical tip and then the parts of the needle contacting the groove wall exhibit wear after play.

Somewhere I've seen a highly magnified photo of a worn steel phonograph needle, but I can't find it now. As I remember, it looked more like a chisel than a tip, at the tip.

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Re: 78 noise

Post by H. callahan » 26 Jul 2019 02:40

grammophone needle before+after.jpg
(76.81 KiB) Downloaded 31 times

Coffee Phil
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Re: 78 noise

Post by Coffee Phil » 27 Jul 2019 17:25

Hi H. callahan,

Those worn styli do look nasty!

Now I would not have too much trouble believing that someone back in the day thought that putting abrasive material into the shellac mix to lap needles, but I think those pictures illustrate that it was not a good idea.

Phil
H. callahan wrote:
26 Jul 2019 02:40
grammophone needle before+after.jpg

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Re: 78 noise

Post by H. callahan » 28 Jul 2019 05:56

Shellac records have been around for about 50 years. If it turned out to not be a good idea they would have changed that very soon - especially because first soundboxes+grammophones were not as easy on the records as later ones.
This picture is to demonstrate that one should change the needle after a single play - and it does show how much a needle can/does wear - wear the record does not have to suffer from as the record wore the needle and not vice versa.

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