Jelco Easy VTA on the Fly

You can't have both. The EasyVTA includes a special base which apparently has "tighter tolerances" than the standard Jelco collar. No idea how it compares to the Ammonite base. (I have 2)
If you want er, easy VTA, this is the best way to do it. 

Very nice and detailed review.

http://v2.stereotimes.com/post/tweaks-for-geeks/

...just a bit of a caution.....as you raise the rear end of the arm, you are decreasing the vtf.  ...not so easy to listen/adjust/listen/ajust, etc.

@stringreen Any idea what difference in VTF occurs for every millimetre of change to VTA? 

stringreen

... as you raise the rear end of the arm, you are decreasing the vtf ...

No, that would increase VTF, not decrease it.

noromance

Any idea what difference in VTF occurs for every millimetre of change to VTA?

You’d need more information to calculate this, including the weight and length of the arm. But it’s an easy thing to measure with a good VTF gauge.