Rega Diamond Mounted 90 degrees?

[HarryAndAGuitar]

Hello all!

I recently got the Apheta 3, I’ve noticed that Rega do something weird with their fine line type profile for the top end cartridges, they mount it 90degrees off, resulting in ‘more stiffness and control over the stylus’.

What are the other effects? Smaller contact area on the groove? More? Does it wear out quicker if so? I can’t really find any information on other styli mounted this way…

 

[Craig B]

'Vital' is Ogura Jewel Industry Co. Ltd's name for their rectangular shank styli. These can be ordered with the major radii oriented across either the wider or narrower dimension. 90º orientation refers to this being across the narrower, indicating that the whole diamond might offer stiffer resistance to longitudinal drag, (possibly) especially so, when pressed through a flattened aluminum cantilever end. Regardless, no matter which way round, a Vital diamond will be half the mass of a standard square shank of same major width and length.

Although Rega haven't published the actual tip dimensions, only describing it as "fine line profile nude diamond stylus", it is likely as not to fit within one of Vital's OEM offerings (try search for 'vital' with me as poster for an image of their OEM stylus options).

 

[dave charlton]

Rega do something weird with their fine line type profile for the top end cartridges, they mount it 90degrees off, resulting in ‘more stiffness and control over the stylus’.

What are the other effects?

No tie wire or damping either, resulting in more stiffness and control equalling more information equalling more music. Weird shit which started with the one piece armtube.

 

[Craig B]

No tie wire or damping either, resulting in more stiffness and control equalling more information equalling more music. Weird shit which started with the one piece armtube.

Aye, I'd describe these as having an invisible inertial damping field. Weird shit which started with the discovery of magnetism.

 

[HarryAndAGuitar]

Aye, I'd describe these as having an invisible inertial damping field. Weird shit which started with the discovery of magnetism.

very interesting.. the cartridge sounds great, I’m just mainly concerned about how much surface area is in contact with the groove and if it has any affect on the cartridge wearing quicker, as well as the records…

 

[Craig B]

very interesting.. the cartridge sounds great, I’m just mainly concerned about how much surface area is in contact with the groove and if it has any affect on the cartridge wearing quicker, as well as the records…

The more surface area the better really, although it is the distribution of the contact patch area that makes the biggest difference when it comes to both information retrieval and reducing wear (of both stylus tip and record groove). This has nothing to do with the orientation of the stylus profile wrt the major and minor rectangle dimensions of these Vital type diamond blocks; more a case of what the major and minor tip radii are (R vs r). Typically, a fine line tip will have far more diamond contact with the groove walls vertically, with more or less the same area contacting the groove walls horizontally as the über-ellipticals of old (Shure's 0.2mil r of their old ED tips, for example). This vertical elongation/extension of the contact patch means that contact patch area is greater than that of even a large conical (say 0.7mil), something that typically lasts a good while longer than a standard elliptical (circa 500hrs vs. 300hrs according to A-T, see P.S. below), where some of the fore and aft portions of the same contact area have been ground away during manufacturing in order to better trace the HF undulations within the groove walls. Because fine line/extended line contact type tips also spread the load over a much larger area this also results in both reduced stylus and record wear. Another thing that you are likely to hear about is 'grain oriented' diamonds; this referring to the hardest sides of the diamond being presented to the record groove walls.

Within the graphic below, you'll notice that 0.5mil conical has greater contact surface area than a standard elliptical (typically 0.3 x 0.7mil these days), with line contact types having far greater contact area than even the 0.7mil conical (despite line contact types typically having smaller minor radii (r) than most ellipticals).

P.S. Although there are many factors at play, audio-technica suggests the lifetime of their styli to be approx. 300 to 500 hours for Conical, 300 hours for Elliptical, 1000 hours for Microlinear, and 800 hours for Shibata and Special Line Contact.

 

[HarryAndAGuitar]

The more surface area the better really, although it is the distribution of the contact patch area that makes the biggest difference when it comes to both information retrieval and reducing wear (of both stylus tip and record groove). This has nothing to do with the orientation of the stylus profile wrt the major and minor rectangle dimensions of these Vital type diamond blocks; more a case of what the major and minor tip radii are (R vs r). Typically, a fine line tip will have far more diamond contact with the groove walls vertically, with more or less the same area contacting the groove walls horizontally as the über-ellipticals of old (Shure's 0.2mil r of their old ED tips, for example). This vertical elongation/extension of the contact patch means that contact patch area is greater than that of even a large conical (say 0.7mil), something that typically lasts a good while longer than a standard elliptical (circa 500hrs vs. 300hrs according to A-T, see P.S. below), where some of the fore and aft portions of the same contact area have been ground away during manufacturing in order to better trace the HF undulations within the groove walls. Because fine line/extended line contact type tips also spread the load over a much larger area this also results in both reduced stylus and record wear. Another thing that you are likely to hear about is 'grain oriented' diamonds; this referring to the hardest sides of the diamond being presented to the record groove walls.

Within the graphic below, you'll notice that 0.5mil conical has greater contact surface area than a standard elliptical (typically 0.3 x 0.7mil these days), with line contact types having far greater contact area than even the 0.7mil conical (despite line contact types typically having smaller minor radii (r) than most ellipticals).

P.S. Although there are many factors at play, audio-technica suggests the lifetime of their styli to be approx. 300 to 500 hours for Conical, 300 hours for Elliptical, 1000 hours for Microlinear, and 800 hours for Shibata and Special Line Contact.

You’ve schooled me man! Exactly what I was looking for, as you can tell, I know nothing about this stuff!