Sirspeedy, the reason that AS is not a good idea with uni-pivot arms is that the horizontal vector imposed at the stylus will cause a unipivot to twist and drive the stylus out of azymuth (and also lower the VTF, due to the upward vector imposed by the torque)since there is no bearing in that horizontal plan to counteract that force. My STAX UA7 was a unipivot arm, which had a very elaborate AS (variable across the disc), but I ended up using very little AS, as determined by listening with a test record.
Dan_ed, if every record were recorded at the same level (level and frequency affect the friction which causes the centripedial force, along with the VTF and the 'lack of tangency'), were of the same length and thickness, then yes I would say that extreme accuracy on the VTF would be worth it. However, as you have mentioned, one cannot get 0.01g repeatability reliably from the VTF mechanisms on todays arms. Even those that claim to dial in the 1.87g and play, will tell you that after they carefully and painstakingly set the VTF to 0.01 precision, they then reset the VTF according to ear.
Might as well set the VTF to 1.9g (with less fuss) and then tune the VTF. It is quicker and just as good, depending on your ears, of course.
Bob P.
Dan_ed, if every record were recorded at the same level (level and frequency affect the friction which causes the centripedial force, along with the VTF and the 'lack of tangency'), were of the same length and thickness, then yes I would say that extreme accuracy on the VTF would be worth it. However, as you have mentioned, one cannot get 0.01g repeatability reliably from the VTF mechanisms on todays arms. Even those that claim to dial in the 1.87g and play, will tell you that after they carefully and painstakingly set the VTF to 0.01 precision, they then reset the VTF according to ear.
Might as well set the VTF to 1.9g (with less fuss) and then tune the VTF. It is quicker and just as good, depending on your ears, of course.
Bob P.