Spindle-To-Pivot Distance

Dear @tomwh : " do the test I wrote about. ":

"" Maybe have a person get a album you are not familiar with then have him play it choosing different spots , with you not looking....... tell him where the null points are on it . ""

Not you, not me and I think no one can tell " him " about those null points and it’s very simple why we can’t do it:

our ears are extremely limited not only in frequency range but way limited to identify some kind of distortions especially distortions of low levels along that we are not trained on purpose to be aware of your posted test but additional to that tracking distortion levels out of the null points are changing its levels ( up and down depending if we are listening before or after each nul point. ) groove to groove and this continuty with to low distortion level groove after groove makes imposible to be aware of it.

These are examples using Löfgren B alignment that always has the null points at 70.28 mm and 116.60mm:

the tracking distortion at 140mm is 0.507% and at 130mm is 0.30%: Do you think that you can identify the 0.2% difference between those 2 grooves?

Now, at 130mm is 0.30 and at 129mm is 0.27%. Could you identify it? I think ( not even with training ) you can’t do it.

Near one null point example: at 120mm is 0.07% and at 119mm is 0.05%, the difference is 0.02% and you want that I try to identify that null point?.
Has no sense to me but was your proposal.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

@tomwh  :  Btw, calculations under IEC parameters.

R.

Clearthinker, I did not say that the 10mm error in P2S contemplated by the OP would not be audible. At best, I said that if he fiddled with his head shell offset and the slots on the mounting surface, so as to move the cartridge forward, he might at least partially correct for the error. After that, I have no idea how it would sound, any more than you do. So sorry if that bothers you. Not.

@lewm , think about it. He is mounting a tonearm that requires a 250 mm spindle to pivot distance at 240 mm increasing overhang by 10 mm. In order to get the right geometry you will have to push the cartridge back in the head shell, back towards the pivot not forwards. Then you would have to twist the cartridge clockwise to get the right offset angle. Moving the cartridge forwards will increase overhang eventually with the results I mention above.

@rauliruegas , That is the most eloquent post I have ever seen you do and you are absolutely right. Anyone who thinks they can hear even 5 degrees of tracking error need to run some blinded tests on their own to learn a little more about their hearing capability. People need to run these experiments to learn what they can and can not hear along with the degree to which your brain can play around with you. 

You have run into the problem that I mention in regards to linear trackers.
The vertical effective mass is too low for most modern cartridges and the bass gets screwed up. This is the reason Clearaudio made the Goldfinger so darn heavy. It makes their arm sound better. Terrible arm IMHO. Just watch one tracking and you will see the cantilever lead the arm and wiggle back and forth. Air bearing arms do the same thing perhaps not quite as bad.
Have you had a chance to hear a Schroder LT yet? I love that design.

Mijostyn, good point but it seems to me we’re both right. Moving backward would preserve overhang at the expense of reducing effective length. Moving forward in the headshell would preserve effective length but increase overhang. Both work if you can also twist the cartridge. Neither solution is orthodox.