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

I have had two Sota Turntables over the span of 39 years. My latest is a Star Vacuum Series VI. It was a series V until the motor died. So I had them upgrade it. The speed is stable in terms of both setpoint and w&f. My older Sota Sapphire Series III with the Pabst DC motor had speed variation and I ended up modifying the suspension to reduce w&f which made it sound much better but it would still have a different set point every time I turned it off and back on.
The Series VI is an A/C motor vs. the Eclipse being DC. I thought about going with the Eclipse but decided to keep cost down and also minimize the modifications. I’m very happy with my choice.
But regarding the excellent isolation properties of the Sota turntables. Over these many years I discovered that the Sota turntable can still benefit from additional isolation. I wanted to share that. I also have tried using the points (or Cones) on the three legs but I went back to the rubber feet. I prefer the sound with the rubber feet. My new favorite isolation configuration is a carbon fiber plate on 4 ISO Acoustics feet. Wood boards work well too. Do NOT put the Sota on a granite slab. I thought that would have been a good thing for the extra mass, but the sound is terrible.
The vacuum improves bass response and also makes the background blacker- at least I think so. But I also like the vacuum because I have a few records that are not perfectly flat and while the clamp alone helps the vacuum platter makes every record perfectly flat.

The effective mass of my SME 309 tonearm with removable headshell  is less than the effective mass of the SME IV or SME V fixed tonearms.  Hmm.  Generalizations can be dangerous.  I agree that fewer connections between the phono cartridge and preamp is better but unless you are soldering the tonearm lead wires to the phono cartridge pins and to the preamp input leads, it is somewhat of a moot point.  1.5 meters of litz lead wire has a resistance of about 10.8 milliohms,.  Each connection has a resistance of 0.5 milliohms.  My tonearm has 5 connections to the preamp vs 3 for the SME IV or V or 1 extra milliohm.  7.5% more resistance using a removable headshell.  But a fixed tonearm with no connections- solder joints only would reduce the resistance between the phono cartridge and preamp by 25%.

For anyone who has ever tried playing the Telarc record of Tchaikovsky’s 1812 Symphony knows that if the tonearm/cartridge combo isn’t right, that tonearm is going to skate across the record when the cannons fire.  Very exciting record. 

That’s right what chakster said.  

Remember, the first rule of Engineering is to watch your units.  Well, we had a professor in college that said the first rule of Engineering is "You can't push a rope."  But if your units are mixed you can get into trouble very quickly.  Also note that a warped record will have a rotational frequency of 1.8 Hz.  If the tonearm/cartridge natural resonance is down below 5 Hz, exciting things can happen when it tries to track over that warp.

The phono cartridge and tonearm combine to make a spring mass system.  The phono cartridge and tonearm must compliment each other to yield the ideal system natural frequency.  That ideal system natural is between 8 and 11 Hz.  Once you decide on a tonearm then you must narrow your selection of phono cartridges to compliment the tonearm you have selected.  You can use this equation: Resonant Frequency = 1000 / (2 x π x √ (M x C)) or easier to use the cartridge resonance evaluator available on various websites.  Take my SME 309/Soundsmith Zephyr combo for example.  Tonearm has an effective mass of 9.5g.  The Zephyr has a mass of 12.2g.  I add about 0.5g for the screws for a total mass of 22.2g.  The Zephyr has a compliance of 10 micrometer/millinewton or 0.00001 cm/dyne.  Use the magic calculator or plug these values into the formula and my tonearm/cartridge system has a resonance of 11 Hz.  Right in the ideal zone.  The Zephyr comes with some ceramic rods to add mass if needed.  So, if I wanted to lower the resonance to 10 Hz, for example I could add 2 grams of mass to the headshell.  Why is the resonance range so important?  The 8-11 Hz range keeps the tonearm away from the music lower limit of 20 Hz (the modulating grooves can excite the tonearm) but also above rumble frequencies.  If a tonearm/cartridge system is mismatched poorly you can actually experience your tonearm moving up and down and cartridge skipping.  From the equation you can see that a low mass tonearm/cartridge needs high compliance (spring rate) and a high mass tonearm/cartridge needs low compliance.  

Speed and velocity can be confusing for one reason the units are the same- ft/sec, miles per hour, or m/s.  For example when driving your car you might maintain a constant speed through a curve and your speedometer shows that your speed is unchanging.  Your velocity, however is changing as evidenced by the sideways pull you experience in your seat.  A change in velocity is acceleration.  Acceleration is a force.  That’s what you feel in your seat as you steer your car through a curve.  The stylus experiences those same forces as it gets pulled through the wavy grooves of a record.