Cartridge stylus : I do not understand

the thin end of the wedge
georgesgiralt
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Cartridge stylus : I do not understand

Post by georgesgiralt » 21 Jul 2019 11:02

Hi !
Give a stylus diamond is so tiny, the material costs are very low compared to the workman force needed for polishing it.
I do not understand how it comes that bonded stylus are less expensive than nude styluses ?
Does the cost of bonding be less than the cost of the extra bit of diamond ?
And to what it is bonded to ?
Thanks for your enlightenment !

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Re: Cartridge stylus : I do not understand

Post by JoeE SP9 » 21 Jul 2019 18:27

It requires less precision and is easier to place a bonded stylus than a nude one on the cantilever.

Bonded styli use an adhesive to connect the stylus to the cantilever. Nude mount styli usually use a precisely placed hole in the cantilever and precise stylus placement in that hole.

Sunwire
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Re: Cartridge stylus : I do not understand

Post by Sunwire » 21 Jul 2019 19:33

Especially if the stylus is conical. Much easier to align to the cantilever compared to an elliptical or fine line stylus that must be exactly 90 degrees to the length of the cantilever and precision aligned to the plane of the record surface, too.

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Re: Cartridge stylus : I do not understand

Post by Woodbrains » 21 Jul 2019 23:40

Hello,

Actually, none of the above answers the OP's question. And, in fact, I think the OP has a point!

The stylus needs to be the same shape and precision, whether it is nude or bonded. The orientation on the cantilever needs to be as precise with nude or bonded stilii. The stilii are always glued into the hole in the cantilever, regardless of nudity or bondage.

Bonding a diamond to a metal billet takes more work. Gluing a bonded stylus to a cantilever requires more glue. Exactly why are nude stylii more expensive? Synthetic diamonds are maybe more expensive as size increases, but we are not talking karats here.

Mike.

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Re: Cartridge stylus : I do not understand

Post by jdjohn » 22 Jul 2019 04:47

It takes a higher quality (and larger) gem for a nude stylus - probably 3 or 4 times the size of a diamond used for a bonded tip. And just like with diamonds used in jewelry, there are impurities, inclusions, etc. to consider, and a bonded diamond doesn't need to be as pure as a nudie.

As Woodbrains mentioned, a bonded tip uses a metal billet, where a very small piece of diamond is bonded to the tip of a metal shank, and then the entire piece is mounted to the cantilever. Nude is obviously when no shank or billet is used, with a larger piece of diamond mounted to the cantilever. Glue is used for both bonded and nude when attaching to the cantilever, with perhaps nude requiring a little less glue due to the square shank holding it in place.

It is easier, and takes less care, to grind a diamond after bonding it to a metal shank. Grinding a square shank of pure diamond requires more care and attention to detail.

Nude mountings are usually ground to have fancier shapes and finer tips, so that comes into play in the overall price. Also, they are normally mounted into better cantilevers that are nice and thin and/or made from something other than aluminum, so again, a higher price overall. Mounting into these thinner cantilevers requires more precision and skill. And since nude diamonds are almost always made from a square shank, there is not much forgiveness during cutting the hole in the cantilever, and mounting the diamond. It is easier to twist a round shank with bonded tip into proper position.

So in the end, nude mountings have higher quality diamonds, ground into fancier shapes, are more difficult to work with, and are mounted to more expensive cantilevers.

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Re: Cartridge stylus : I do not understand

Post by Delta667 » 22 Jul 2019 07:09

For me, it remains a mystery how the diamond is connected to the metal base on the bondage stylus.
Maybe someone knows and will share information?
This is anything but glue.

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Re: Cartridge stylus : I do not understand

Post by DeepEnd » 22 Jul 2019 14:05

I always thought the method used to fix the bonded tips was brazing (heating two materials with a suitable "filler" rather like a very high temperature soldering) but found the following descriptions.

"There are two ways that make it possible to braze diamonds. The first is by plating the diamond, then brazing. The second is by using a braze containing a good carbide forming element, such as titanium, zirconium, tungsten or iron"

"When brazing diamonds consideration needs to be given to the furnace atmosphere, as high partial pressures of oxygen will attack (oxidise) the diamonds and any carbide forming elements in the braze alloy. Typically vacuum, inert gas and hydrogen atmospheres are employed"

This is possibly why most shanks are iron/steel or sometimes titanium?

I think the amount of diamond used for bonded tips is very much smaller than a nude (perhaps a tenth?) and the nude needs to be grain oriented to make the outer (non ground) part of the tip.

I suspect the bonded tips are not grain oriented and perhaps may even use the "offcuts" from the more expensive cuts and/or other processes/products (e.g. from making jewellery?) where the main product covers most of the production costs hence the lower costs for bonded types.

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Re: Cartridge stylus : I do not understand

Post by DeepEnd » 22 Jul 2019 14:09

How about this for small piece of (nude) diamond? This is a 0.26mm diameter boron rod with very worn a Weinz Paroc stylus fitted.
Cart-000008.jpg
(21.79 KiB) Downloaded 153 times

markcass
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Re: Cartridge stylus : I do not understand

Post by markcass » 22 Jul 2019 14:16

My understanding is that the more basic conical and elliptical bonded styli are not hand-finished, but polished in bulk. A quantity of 'raw' bonded assemblies would be placed in a drum with a specified amount and grade of polishing/grinding paste and then 'tumbled' in a specific way for a controlled period. The original diamond chip and metal shank would obviously be quite rough and imprecise in shape before processing. This would certainly help to explain the lower cost of such a stylus.

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Re: Cartridge stylus : I do not understand

Post by JDJX » 22 Jul 2019 14:30

JoeE SP9 wrote:
21 Jul 2019 18:27
It requires less precision and is easier to place a bonded stylus than a nude one on the cantilever.

Bonded styli use an adhesive to connect the stylus to the cantilever. Nude mount styli usually use a precisely placed hole in the cantilever and precise stylus placement in that hole.
Not really.... A bonded stylus is also precisely mounted in a cantilever in a precisely place hole.
both require the same exact precision ......... and both are a bonded to their cantilever

Bottom line, a good bonded stylus is every bit as good as a nude stylus .
A nude stylus is more expensive simply because it uses a bigger diamond and so, the manufactures feel justified to charge more.
Fact is, the tiny diamonds such as used for a phono stylus are quite common and readily available in large quantities .
It's the shaping and polishing of the diamond that require precision and both the nude and the naked stili are shaped and polished in exactly the same way..

Now.... some claim that a nude stylus weights less that a bonded one but this has never really been proven and we must keep in mind that diamonds have weight also and, a bonded stylus' shank is always made of light weight material. :)

BTW ,consider the original SAS...
It has nude diamond but it is attached to the cantilever by a globe glue that obviously has some weight. ..

So, a bit of reality over all is in order about what is really important .:)

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Re: Cartridge stylus : I do not understand

Post by Delta667 » 22 Jul 2019 14:45

DeepEnd wrote:
22 Jul 2019 14:05


"There are two ways that make it possible to braze diamonds. The first is by plating the diamond, then brazing. The second is by using a braze containing a good carbide forming element, such as titanium, zirconium, tungsten or iron"

"When brazing diamonds consideration needs to be given to the furnace atmosphere, as high partial pressures of oxygen will attack (oxidise) the diamonds and any carbide forming elements in the braze alloy. Typically vacuum, inert gas and hydrogen atmospheres are employed"

This is exactly what I could not find)).
I could not understand how to solder a diamond with molten metal if its burning temperature is 850 degrees Celsius.
I do not know how others, but it is easier for me to process a bare diamond than to solder it to metal))

It remains to razgodat, how to connect two diamonds. Probably heating them to a temperature of 4000 degrees in a vacuum.

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Re: Cartridge stylus : I do not understand

Post by JoeE SP9 » 22 Jul 2019 15:11

JDJX wrote:
22 Jul 2019 14:30
JoeE SP9 wrote:
21 Jul 2019 18:27
It requires less precision and is easier to place a bonded stylus than a nude one on the cantilever.

Bonded styli use an adhesive to connect the stylus to the cantilever. Nude mount styli usually use a precisely placed hole in the cantilever and precise stylus placement in that hole.
Not really.... A bonded stylus is also precisely mounted in a cantilever in a precisely place hole.
both require the same exact precision ......... and both are a bonded to their cantilever

Bottom line, a good bonded stylus is every bit as good as a nude stylus .
A nude stylus is more expensive simply because it uses a bigger diamond and so, the manufactures feel justified to charge more.
Fact is, the tiny diamonds such as used for a phono stylus are quite common and readily available in large quantities .
It's the shaping and polishing of the diamond that require precision and both the nude and the naked stili are shaped and polished in exactly the same way..

Now.... some claim that a nude stylus weights less that a bonded one but this has never really been proven and we must keep in mind that diamonds have weight also and, a bonded stylus' shank is always made of light weight material. :)

BTW ,consider the original SAS...
It has nude diamond but it is attached to the cantilever by a globe glue that obviously has some weight. ..

So, a bit of reality over all is in order about what is really important .:)
If you look at a bonded stylus under a microscope you will see the shoulder of adhesive (glue) holding it in place. Nude mounts have no shoulder of adhesive. I'm not saying one is better than the other. However, manufacturers always charge more for a nude mount regardless of the shape of the diamond.

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Re: Cartridge stylus : I do not understand

Post by Boltman92124 » 22 Jul 2019 15:37

I was sold on the superiority of a nude stylus vs bonded when I upgraded the bonded AT100e to the nude 120e.

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Re: Cartridge stylus : I do not understand

Post by DeepEnd » 22 Jul 2019 15:45

OK my take on the effective mass of tips is that the most common material for bonding tips is steel, sometimes brass or titanium but not often aluminium (perhaps a bit soft for processing?).

Most bonded tips are circular so the volume of a bonded tip would be greater than a square stylus whose diagonal is the same size as the diameter of the shank. This alone reduces the volume by over 36%!

If the nude tip was 1mm x 1mm (I know it isn’t but it makes the maths easier) then the area would be 1mm2.

The diagonal would be 1.414mm and a circle of this diameter has an area of ((1.414/2)^2 x Pi) 1.571mm2 or 57% more!!

Diamond density is 3.51g/cm3
Titanium 4.5g/cm3
Steel 7.8-8.0 g/cm3
Brass 8.7g/cm3
Tungsten 19.3g/cm3

Aluminium has the lowest density at 2.7g/cm3 but a circular shank of aluminium would weigh about 20% more than a square diamond.

Titanium about 70-100% more.

A steel one would weigh between 2 and 3 times as much.

Yes I would expect a nude tip to be lower effective mass.

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Re: Cartridge stylus : I do not understand

Post by lini » 22 Jul 2019 15:50

Mike, JDJX: There isn't necessarily a hole. For example, if you look at an ATN150MLX, you can see that the diamond is glued directly onto a bevelled surface next to the front of the boron rod - which is why it's surrounded by quite a lot of glue. Another, slightly differenct form of "glue-on mount" can be seen on of some of the Technics carts/needles with boron tube, like for example the EPC-P22, in case of which the tip is glued to the very front of the tube.

And of course the bonding socket doesn't always have to be made of metal. Philips, ADC and Goldring for example also used to offer sapphire-bonded tips(which ADC used to call "Diasa" - another form of what I refer to as "luxury bondings" (just like those on titanium) due to being lighter than those on (most usually) stainless steel or (as used by Grado) on brass. Titanium bonded tips have also been offered by Philips - but also by AT, typically for their bonded Shibatas (or renamed Shibatas alias LinearContacts) e.g. in case of the ATN125LC/122LP.


Joe: Sorry, but you're wrong in that case. Nude mount doesn't mean glue-less mount. Most nude tips are "pierced-through mount", though, so you need to look on the other side, i.e. on the upper side of the cantilever to see most of the glue - whille it'll depend on how tightly the shank fills the hole (and presumably also the viscosity of the glue), how much of the glue makes it to the business side.


Greetings from Munich!

Manfred / lini

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