DaVinci tonearm and azymuth

Hi Pasg,
having read all the previous inputs I suspect the mounting base is not level with the platter or the pivot post not 90 deg. relative to the plater level. This would cause an azimuth off-set from the arm post relative to the platter...
If this (for what ever reason) is the case, it can be checked with a small level on top of the head-shell. It could possibly corrected --- at the source of the trouble.

Note: IF the arm post is correct (90 deg. with the platter) the azimuth deviation ought to be of the same off-set at the start, middle and end of the record. ALSO, this measurement is ONLY correct if the head-shell is very close or at the level position where the stylus contacts the record!

In the case of my SME V arm with SME 10 tt, I had to shim the arm mounting by ~ 0.2 mm to correct for such a deviation.
In this case it is an issue with the arm's pivot-post somehow not aligning a proper 90 deg. to the mounting base, (which in my case is level relative to the platter)
Yet, playing with out the shim, I can not detect any shift in imaging or one side louder then the other, it is not enough of a deviation (I think). However, when corrected there is less miss-tracking, OR groove distortion with very critical tracks :-)
Axel

Hi all,
as I mentioned in another thread just now, in the case of the SME V the locking of the arm-post in the case of the V allows for some 1-2 deg. tilt relative to the mounting surface. If I read Halcro's comment with the VTA lifter = threaded rod, I think immediately of the same being the case with the SME V.
In fact I have given up using this "tool" altogether and now use a number of shims made of hard wood --- which also is a bit more "repeatability" then some threaded rod that happens to push the arm post *always* to the opposite side of the where the threaded rod is located.

Ladies and Gentlemen ---- so much for azimuth precision!
Guess why Graham's Phantom II has now an added, permanent "spirit bubble" to his latest creation...
Greetings,
Axel

Hi Doug,
if the arm-post is tilted relative to the platter (not 90 deg.), the azimuth keeps on changing from beginning to the end of the record, aye.
Why? Because the bearing (most usually has a ~ 20 deg. off-set relative to the straight axis of the arm). One thing I learned real fast when using some cheap arm (Pro-Ject 9c) with a sloppy arm collar for setting VTA.
Go figure... and Dertonarm should concede being in touch those Egyptian geometrists :-)
Axel