Basis Vector 4 arm question

I have had other arms that were damped and the amount does make a difference but the effect on the sound depends on the cartridge and rest of the system, I never found any rule except experimenting till you have it the way you like it.

Many people have had experience with it, in this and other unipivots. In general too much damping sounds, well, like too much damping! Dull, slow, attenuated highs, sluggish, flat, undynamic etc. Too little damping sounds bright, aggressive, edgy, etc.

Also speaking in general, TINY changes in the amount of fluid are audible. I've heard differences on a Graham 2.2 by removing or adding the smallest amount possible using the point of a pin. The sweet spot for damping fluid, at least on that arm, is extremely tiny. This was true with 5 or 6 different cartridges. Each one needed a different amount, as Stanwal suggested, and it took experienced listeners hours, not minutes, to find the right amount for each one.

Most important, until you've optimized VTF, SRA/VTA and Azimuth, playing with fluid damping is putting the cart before the horse. You can't tell whether you need ANY fluid until you understand the basic behavior of a specific cartridge on a specific tonearm. Fluid damping, if any, should wait until you're confident all setup parameters are optimal.

I have the Vector 3 tone arm on my Basis TT, and have experimented with using different amounts of silicon fluid in the well, and to me the most balanced sound comes from when the fluid was at the bottom of the radial bearing as the instruction (AJ) told me to do. I find that when I have the arm sitting level on the sharp pointed stem, the flat surface underneath the arm should just touch the surface of the silicone fluid.. It shouldn't be submerged and drenched in the fluid.

The amount that AJ recommends should be the minimum amount to use. You can experiment with more but I wouldn't recommend using less.

I agree with Gslone and Dre, the Vector has to have damping fluid to work properly. Start with just enough to reach that vertical bearing.