Micro-ridge styli


Has anyone ever checked to determine whether the ridges of a micro-ridge stylus are perfectly perpendicular to the cantelever on their cartridge?

I'm wondering about this because we usually look at the cantilever when adjusting a cartridge so that it's tangent to the groove. If we do this for a cartridge with a micro-ridge stylus and the ridges aren't exacty perpendicular to the cantilever, the stylus won't be optimally aligned with respect to tangency even if the cantilever is tangent to the groove (a line drawn through the two ridges should be parallel to the radius of the LP).

I know that variations exist in stylus rake between identical cartridge models, so I'm just going out on a limb and assuming that variations might also exist in the "rotation" of styli in cantilevers. This question does not only apply to micro-ridge but also to line contact and, to a lesser extent, elliptical cartridges.

Any ideas on how to analyze the relationship between the cantilever and the ridges? A scope and a test record? Viewing the stylus from the bottom with a high powered microscope?

Which cartridges today have micro-ridge styli?
ketchup
I don't think you need "high power" to view the stylus. 30x to 50x should do it. I just bought a Peak 50x microscope that works very well because it has a clear plastic base that allows you to set it on the kitchen table and focus on the stylus. At 50x, you will not see very much of the length of the cantilever, 40x might be better for your purpose. I have been using the microscope to set SRA. A blob of Play-Doh sitting on Saran Wrap works perfectly as a base for viewing the stylus as it sits on an LP. I see Peak microscopes on a site called Edmonds.....I got lucky on Ebay. Let me just say thanks to Neil for his excellent posts regarding SRA.
A test regime using a mono record should work. Perfect tangency would result in identical signals from each channel, exactly in phase. A signal analyzer would allow you to measure this.

Of course, on a pivoting tonearm perfect tangency is still only possible at the two (or one) null points available from the alignment protractor. Unless you're using a linear tracking arm, "perfect" stylus-groove tangency is impossible.
Even though a pivoting arm can never achieve perfect alignment, it still seems that you would want perfect tangency at the null points so you don't compound the problem at the other points. In this regard, pivoting arm owners should be the most concerned with perfect tangency at the null points... IMHO, of course!
Ketchup,

If tangency is off by a tiny amount at the target null points it will necessarily be on at some other null points. This will not necessarily increase tracking distortion at non-null points, it could just as easily reduce it. Sonically it might be better for some LP's and worse for others.

Every alignment scheme for a pivoting arm is a compromise. Baerwald aims for lowest overall averaged distortion. Stephenson aims for lowest tracking angle error on inner grooves. Etc. No scheme is or can be perfect. Seeking perfection here is like seeking perfection in anti-skate: it doesn't exist, it never will.

Of course it would be bad if a stylus were very far off, but otherwise it seems a bit academic, IMHO of course! ;-)

Tolerate equipment, enjoy music!
Doug