Question on FR 66s

MIT

The problem with using protractors based on fixed pivot to stylus and overhang is that any deviation in mounting distance or cartridge/headshell constraints render the protractor useless. I prefer to use a universal protractor such as the 'Stupid' Universal here
http://www.vinylengine.com/cartridge-alignment-protractors.shtml
It uses 2 inner and outer null positions and you have to adjust overhang and alignment of the cartridge together to minimise the error.
Using a universal protractor will enable you to align for any mounting distance distance from 230-231.5mm.
For the FR64S and Dertonams suggested 231.5mm, you cannot adjust it via the headshell as Halcro suggests because you will end up with a different overhang. You must have the mounting distance correct.
Going from 230mm to 231.5mm mounting distance is a tiny reduction in tracking error, but having said that I have mounted my FR64S at 231mm and it sounds much smoother than 230mm.
The other factor in Dertonams recommendations is using an outer null point closer to the inner null point which will increase tracking error on the outer grooves but reduce it on the inner 2/3 of the record to provide better tracking of inner grooves.
You can easily make your own protractor with revised optimisation of inner grooves by using the Baerwald template above and simply moving the outer null point/grid closer to the centre.
Interestingly the Naim Aro that I own uses this same philosphy as Dertonams recommendation of optimising the geometry for the inner grooves.
I prefer Baerwald A for all my pivoted arms including the Dynavector which was designed for Stevenson.

Halcro -

And yes......I have listened to the differences between the 230mm distance and the 231.5mm.........
However I don't think this will solve the problems you have described Suteetat?
I have plenty of 'play' distance for all headshells I have tried on both my FR arms to align for ALL the known geometries.

Halcro I may have misread your post - this implied to me that you were suggesting that the pivot to stylus distance could be accommodated via the headshell, which it obviously cant. I assume you meant to say ALL known geometries for a mounting distance of 230mm?

Thanks.

Halcro - I have to agree with Raul, your numbers dont add up.

05-15-13: Halcro
The MA-505s was no problem because it's overhang is the same as the FR-66s.....however the FR-64s has an overhang of 12mm as opposed to the 15mm for the others.
So to correct for that......I reset my P to S to 233mm for the 64s.
And yes......I know that the Av and Max distortion levels go up as a result.

The FR66 should be 12mm overhang not 15. The FR64 should be 15, not 12.
If you are running 12mm overhang on your FR64 then you should be moving the arm closer to the spindle to reduce distortion, not further away.

05-19-13: Lewm
Dear Henry, I am a bit puzzled about a recommendation for a specific headshell offset angle to go along with the recommended P2S distance and overhang for the 64S. In the case of headshell offset angle, isn't one "stuck" with the built-in angle?

Option 1 - Buy a headshell with slots
Option 2 - Drill the headshell holes oversize
Option 3 - Drill the cartridge holes oversize
Option 4 - No bolts, superglue the cartridge to the headhsell
Option 4 is the best sounding, but you need to keep the glue ultra thin for maximum energy transfer.