How to choose an upgraded tonearm.

Tonearms, regardless of specific design points are captive to the laws of physics. Effective mass and cartridge compliance determine resonance. Effective length determines tracking error - especially important when using Shibata or other thin-line stylus designs. Bearing design is at the heart of the conflicting tonearm design requirement of infinite mass, which gives the stylus a firm platform to work against, minimizing loss of dynamics and zero friction allowing the arm to move freely as it tracks across the vinyl. What shortcoming in your current rig do you feel are addressed by a new arm?

The major argument against mounting the tonearm on an outboard pod is not the fact that pivot to spindle distance is subject to variation, if the pod is inadvertently moved in relation to the spindle, although that certainly is a major secondary consideration.  The major argument against is that the separated pod will likely exhibit differences in resonance properties in relation to the spindle and bearing; this will cause minute relative movements of one vs the other.  You don't want that. You want the tonearm pivot, spindle, and bearing to be together in a closed system.  That said, there are a few outboard pods with sufficient inherent mass that they work OK, if also in contact with a subchassis that is shared with the TT chassis.  There was a ridiculously lengthy thread on this topic, started by Halcro.  Search on the keyword "Copernicus", if you want to revisit it.

Can someone show me the math or physics that says the tonearm pivot must be in the plane of the LP surface?  The idea sounds "right", but I am trying to visualize why.  I start with the principle that certainly the center of mass of the counter-weight should be in the plane of the LP surface, but I'm not sure how we get to the pivot.  There are oodles, probably a vast majority, of tonearms where the pivot is not in the plane of the LP surface.  Many of them are terrific tonearms.

Mijostyn, I do have one of the VPI periphery rings to use with warped records. It weighs a ton and seems to work fairly well in flattening them out during play. Thank you for the suggestion on the Rega RB3000 tonearm. The price is right.

Are you thinking the Rega RB3000 tonearm would be functional height-wise, as well as fit on the Classic 2’s tonearm platform after the unipivot point is removed? I’d much prefer not to have to perform any surgery or drilling to install one. I looked at the Rega RB3000 tonearm manual and it appeared drilling was in order, I could easily be wrong though, as the installation instructions were pretty skimpy for models other than Rega’s own turntables.

The VPI platform has a hole on the platform centered under the tonearm base to bolt a new tonearm’s base into, Seems like a simple arrangement, but maybe uncommon for aftermarket tonearms to have a stem on the underside of their base .

Pindac, thank you for the explanations and clarification on using a pod. This whole subject stemming from getting a new cartridge is more difficult than I’d expected with the limited options available in tonearms suitable for the VPI. At the outset the last thing I was considering was a tonearm upgrade. Nothing good comes easy though.

Panzrwagn, the shortcoming I’m trying to address is that some here have pointed out a gimbal tonearm would be much better than the unipivot tonearm on my VPI Classic 2 to use with a newly ordered Lyra Kleos cartridge.

Mike

@lewm , just watch this and it will explain it ....too most people.

Lew, you have to watch all the way through. I know you are going to find it boring after the first 30 seconds. I think even you will understand it. I have posted this on numerous occasions right in front of your face, this time you might try watching it. The vertical bearing problem is a matter of simple geometry. Since I am no good at explaining simple things, watch the video. This fellow is really quite good. 

@skyscraper , Those rings are a PITA to use and dangerous. They also do not totally flatten a record and add a lot of stress/mass to you bearing.

Once you post a link screwy things start happening and you can't post further or make correction.(your bearing).

@skyscraper , to continue I think reflex clamps like the ones JA Mitchel and Sota make are your best bet after vacuum clamping. They are less of a hassle to use and are near as dangerous. Do they improve what you hear? If you record is not flat then absolutely. The brief alterations in pitch that occur are probably worse than the worst wow any modern turntable would reproduce.

"If the record is not flat."  I am sitting here at my desk with my turntable directly to the right with my eye right at stylus level. A 180 gm copy of Take Five is playing as I type. It is sucked down tight to a very flat mat and platter. The cartridge is just slightly gyrating all over the place. Back and forth horizontally due to eccentricity of the spindle hole and up and down due to irregularities in the surface of the record. This record is actually pretty good. All these issues in tonearm design matter. There is no real excuse to ignore any of them. I suppose sometimes you have to compromise.