SOTA NOVA, HR-X VPI, Technics 1200G recommendations?


I am considering SOTA NOVA, used HR-X VPI and Technics 1200G TTs. I have an old SOTA STAR with vacuum, (and essentially a Jelco 750 arm-retipped Denon 103R) so I know its high quality and durability. Technics apparently has performance that far exceeds its $4000 price tag. For tonearms, I am down to Jelco 850M and old FR-64S. I am considering low compliance cartridges. For VPI, it would be JMW 12 or 3D. Changing the tonearms seems to be more of a hassle on VPI. What are your thoughts and recommendations?
128x128chungjh
No. What I am referring to is the fact that velocity is not a parameter to be found in the equation for the force of friction. And friction is the basis for the skating force. All other things being equal, friction is the same at 33 as it is at 45rpm. I take your minor point that groove tortuosity does seem to contribute to the skating force. Or what we observe as a skating force. I think that is because the tortuosity of the groove causes tiny accelerations and decelerations, i.e., changes in velocity of the stylus. Every time you have a change in velocity you have an acceleration. Every acceleration generates a force (F=ma). So my hypothesis is that the contribution of groove tortuosity to the skating force is due to these accelerations, which are not really due to friction. In that sense, Ralph is correct.
@lewm  I have to admit its an assumption on my part that people are playing LPs have have something other than a steady tone :)
@lewm , in the record industry groove velocity is almost a synonym for groove tortuosity. Groove velocity is the distance the stylus travels in the groove divided by time usually in cm/sec The more heavily modulated groove has a higher velocity as the stylus must travel farther. You are referring to groove speed as not affecting friction which as you have mentioned many times, it does not. But, you agree that groove velocity certainly does! 
@atmasphere,that is a reasonable assumption except maybe for millercarbon:-)
If you read the article Hugh Finnimore, Disc cutting in theory, Studio Sound and Broadcast Engineering, July 1975 Studio-Sound-1975-07.pdf (worldradiohistory.com) and can tackle the math you will get a much better 'technical' understanding of what is actually happening with the stylus.  When talking about the record velocity - the important item is groove velocity - 'tangential velocity' (also called the linear velocity) - and for a 33 rpm 12" record this is decreasing from about 51 cm/sec at the outer groove to about 20 cm/sec at the inner groove.

This is going to come as a shock, but stylus acceleration can exceed 1000-g's.  This is not a typo, and in-fact, when cutting the record, they generally adjust parameters to generally limit the stylus acceleration to 2000-g's.  The acceleration is a function of the stylus velocity which is driven by the frequency to reproduce, and the signal amplitude (displacement) which is often called modulation.  But, the inner groove is the most difficult for reproducing the higher frequencies and largest modulations which is a challenge for classical music with its end of program crescendos.

The stylus radius - its profile - has a profound effect on the ability to trace the highest frequencies and largest amplitude/modulation; and this where the advanced profiles such as Shibata come in.  Read the above article for real technical details.  The magazine also has a survey of some of  the cutting machines that were available.  When you realize the enormous accelerations that are occurring it may make sense why some cutters such as the NEUMANN are rated at 500W/channel and the cutting head has to be helium cooled to achieve highest groove-velocity.

In this old Stereophile magazine - the next to last page, there is a good composite plot of the velocities and the displacements vs frequency with limits of the stylus radius for a 33 rpm record -  Stereophile-1964-08.pdf (worldradiohistory.com).  You will see similar composite plots in the  Studio Sound and Broadcast Engineering, July 1975.
@antinn , Thanx for a very lucid explanation. 1000G's, that means the groove is subject to a force 1000 times the weight of the stylus over the styluses contact area. A formula 1 driver is subject to something like 5 G's under braking. 1000 G's that is nuts.