Spindle-To-Pivot Distance


Hello.

Suppose I have a tonearm that wants to be mounted 250mm from the spindle.  But it would be a little hangy-off the edge at 250 but I could mount it cleanly 240mm out.  What's the worst thing that could happen if I do 240?  Do I hear 245?
mrearl
If you are looking  for a answer to your question  you probably  came to the wrong forum.   Some engineers  way  back in time came up with the two null point system and the various percentage of distortion  from there.  There  seems to be 2 to 3  popular  null point systems.  So if  you go by there  methods you have 2 null point with everything  is supposedly  perfect and the rest  goes into various  degrees of distortion.   Love to meet the guy ,without seeing the  record, who could pin point the null points with his ears.

Now you are talking 10mm which is  a pretty good distance.   If you have  reasonable math/ engineering  skills you can go to vinyl  engine and use there calculator  to see if you can get 2 null points and where they would be  using the 240 and  250 mm  mounting  distance.   Then maybe take  a record that  did cost 100.00  and try it  at 240 mm.  

I do not know how  involved  you wanted to get  but  thought  I would give you the option  to be able to understand  a little bit  of what is going on.  There are  guys on other forums  who will do the math for you or  run the calculators for you.

Enjoy the ride 
Tom
If the slots in your head shell, presuming you are using a head shell, are long enough you could possibly make up the deficit by moving the cartridge forward in the head shell and twisting it slightly with respect to the long axis of the headshell. Then you might achieve only a small tracking angle error, rather than a large one. Use a good protractor if you go this route. While I respect the opinions of the other knowledgeable persons who commented here, I personally do not think there would be such a dramatic reduction in sound quality, if you were able to make up for the pivot to spindle distance in the manner that I described.
Well, this collection of answers gives me a good grounding.  And a minimum of snotty gay comments like I get in other forums.  Thank you all.  I could as well mount the arm off the original 'table but I think that there's something to having a strict connection from platter to tonearm.  But there's certainly a hierarchy of considerations.
Over and out.  Thanks.
10mm error in PS distance is too much! 

But theoretically if you have detachable headshell with long slots for the mounting screws you can compensate 10mm. In the end it will be ugly as hell. Your cartridge will be moved way too forward in the shell (10mm more) and twisted a bit. 

I would’t do that, you’d better change the armboard with correct mounting hole for your tonearm and given PS distance (using original template). 

What’s your tonearm?
I know I’ll get hate mail, figuratively, but anal attention to alignment is overrated in my opinion, as regards the effect of slight misalignment on audible distortion.