How much difference if the tonearm is mounted 5mm

Hi Stringreen,
I am adding a second arm on my turntable. My turntable came with the JMW 10, so the armbase does not accomodate with the new arm wand. I have to change the whole set to the 3D, a bit expensive right now.
As fir the new arm, it is shorter than spec. Hence the question.
Thanks,
Calvin

Calvin ... did you try a Baerwald (sp) protractor? Just curious if you still come up short.

Hi Bifwynne,
Yes, that was the one I use to set up the cartridge at first. I also checked the leveling of my table and armboard. As of right now, i beleive that the arm is deffected. It was made shorter than the specs by mistake.
Thanks,
Calvin

Calvin, thanks for the clarification. It sounds like you are correct about the arm being off spec. The only other logical conclusion is that the Feickert protractor is off spec. If the Feickert works fine on other arms then that would rule it out as a suspect.

Assuming you can mount the arm where ever you want. With a Feickert protractor (own one myself) you can just mount the arm where you end up with the cartridge in the middle of the head shell slots, and still get the stylus in the middle of the cross marks on the protractor. This is where the arm should be mounted. The only draw back is the head shell offset may be a little off if it was designed to work with a 212 mm P2S distance. If this is the case do not aligning the cart offset to the head shell. Just align the cantilever (front to back) with the marks on the Feickert protractor, which should be done regardless.

This would work for any arm you do not know the P2S distance on as long as you are using the Feickert protractor, or one that is of the same design.

Regardless I would contact the manufacture and try to get a replacement if the arm is not to spec, because this would make the arm impossible to resell if it is off. Someone else may not have the flexibility to mount the arm at a different distance than what is specified.