Thank you for the wonderful review of your Soundsmith Strain Gauge SG-200 system; It provides me great satisfaction to know that each one I hand make is appreciated. I do agree with you that a line contact stylus, and especially our SG-6 Optimized Contour design, which does contact about 70-90% of the groove walls, is more likely to accumulate residue and debris left in the grooves than an elliptical or concical, expecially due to the force-per-unit-area which is greater for these other types of styli shapes. It may well be that due to such, they "push" debris, or even self clean the contact area to a greater degree than more esoteric shapes do....however, due the radiius of curvature problen, they of course, may not trace as well....
Peter Ledermann/Soundsmith