The relationship between VTA and VTF

Don't know if this will help...
Fine tuning your turntable
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I'm not sure what a "stable balance" arm is as opposed to a "neutral balance" arm. I think that virtually all pivoted arms will exhibit this trait-I know mine does. You can drive yourself crazy with this stuff if you let it. I don't have any VTA on the fly capability so I simply adjust VTF to be at the high end of the range I want with thicker pressings knowing I'll have a little less VTF with normal records.

I would be curious about the "neutral balance" of the Phantom though and whether or not it really eliminates this if anyone can elaborate.

The Graham 1.5 has a balance CG below the pivot bearing. If you look at the arm like a sideways "L" (------i)then perfect balance happens when the arm is level, the bottom of the i is heavier then the dot in the stable config. Any up or down change from level (gravity) will have an impact on tracking force +,-. If the back of the arm is low and set for a thin record playing a thick record would increase VTF and of course change VTA a bit. The greater the config from level the greater the change would be. I set my VTA by ear then reset the VTF at that record height using a stand for my gauge then set VTA again. So far for me the VTA has a greater impact on sound that changing the VTF from recommended value. My arm is about level and VTF changes are, .o6 grams or so. I am a set it and forget it type of user so I will set it for the best compromise and leave it. I have regular records (120 gr?), 180gr and some 200gr. Looks like if I had a record in the 150-160gr range that would do me.

I image "stable vs neutral balance" impacts other parameters as any up or down or sideways movement is now a bit different because of the CG change.