Tracking error distortion audibility

Dear Frank: Welcome a-board.

+++++ " What is the threshold for the audibility of tracing error related distorsions? "+++++

IMHO the " start " subject here is to define/identified first which are and how we hear those related tracing error distortions over the frequency range, certainly we can but is not an easy task especially if we want to define the threshold/limit.

There are some " difficulties/obstacles " other than system quality performance: the wide differences on the velocity recording through the LP, certainly the tracing error related distortions are different at outer grooves than at medium or inner grooves and we have to identified over the whole record, as you point out we have additional " problems " because of stylus shape, different tonearm/cartridge combinations could be more or less " tolerant " about, our ears and know-how level is important too, there is other subject: there are distortions that are incorrect but we like it ( many of us do not like low distortion sound, many people likes higher distortions/colorations. That's why we have to identified the incorrect distortions due to bad geometry tonearm/cartridge set-up. ), etc, etc

Of course that we can do it in a scientific way making measures and then listening till we find for specific grooves the limit to start/begin to hear " distortions " related to tracing error due to bad geometry set-up.

From my mistakes/errors ( like the one I posted elsewhere with the FR702. ) experiences and due that we live in an analog imperfect world it seems to me that that threshold is wider than what we imagine and cmplex to be absolute precise by ear only.

In the mid-time we have to take care on every single step on the tonearm/cartridge rigth and " precise " set-up.

The 90% of what the people ask in this forum, one way or the other, are related with distortions ( everywhere and any kind ) due to an incorrect audio items set-up.
I repeat again, we have to take care on a precise audio link set-up on the audio chain.

Anyway, I know that there are other tonearm designers that are reading this and other related threads, I hope they want and can joint us to share their thoughts and experiences about.

Regards and enjoy the music.
Raul.

Frank,
thank you for all that common sense approach.
I happen to be a trained engineer myself (old school German Mechanics) and I can only agree, that IF you need to get 'anal' about some of these setting, be aware what is 'value added' to improve things, not just for the sake of doing 'something' that might be of little effect in practical terms.

Having said that, in my present experience and so far with two of Ortofon's top MC's --- they have a problem to get their motors in the middle of that sintered body shell. Funny thing, it is hardly, if at all, an issue with their cheaper lines i.e. the Kontra-Punkts. It is to my dismay an issue, that for some unknown reason, with their more expensive Jubilee and PW lines.

What seems a constant here, is the motor being closer toward the left cheek of the body (looking from the front). This creates some, at least for me, more intricate issue since the cantilever is straight as such!
Of course, not being anal about it, just turn the cart a little to the left, if 6:00 o'clock was straight, say to 6:03, and call it a day.

Being now being anal about it, the cart would have to be actually offset at 6:00 to the right, i.e. NOT turned, but shifted toward the right to compensate for the left offset of the motor. The offset is about 0.3 mm and quite noticeable by only looking at it, straight from the front.

In your experience will it be all the same, or actually make a difference in practical terms (in geometry there will be a difference, I say)

Greetings,
Axel

Dear Berlinta, the choice of an inner (2nd) zero close to the label makes sense too, if you own a large collection of early classical stereo LPs made by Mercury and/or Decca (to name the 2 major labels who hadsome of the most daring cutting engineers...) in late 1950ies and first half of the 60ies.
Ask hundreds of collectors of valueable vintage LPs.
Here we often have run-out grooves sometimes starting within less than 8 mm before the paper label. Especially with some of the most dynamic recordings. And then the large final tuttis are very close to the grooves end.
Its not all singles.......

There never was a "norm" from IEC and the AES for the stylus - mounting holes ?
Well - there was and is one.
The fact that so many manufacturers do not obey to it, doesn't mean there is none.......

Anyway - these are windmills....... I won't make the same mistake as Galileo did. I leave the discussion in this thread for good - this step will surely get some applause, as it leaves the field to others to shine........ and increase their sales.

Dear all, after we have now learned that finally all parameters of the tonearm geometry are variable, nothing can stop us now entering analog heaven.
If any of you will still suffer inner groove distortion....... well, don't worry that happens. Move your tonearm, rotate the cartridge. If it distorts now at the run-in grooves? Hey - be flexible. Times may be hard, but modern.

Hello Peterayaer,
An arc protractor works perfectly for one specific effective length only. This requires the cartridge to be moved (i.e. in the headshell slots) to match that length as precisely as possible. Any arc protractor designed for a particular arm cartridge combination(-your question above) should have taken actual measurements as a base for fabrication. Unfortunately, as described by Jonathan Carr, the sample to sample variation in cartridges(screw hole to stylus distance) often exceeds what could be seen as an acceptable tolerance (= below human eyesight limitations), resulting in grounds for error even if the same arm and cart model are used.

But the Null points on an arc protractor are valid regardless of the arc itself. It is only the circle segment line which needs to be re-drawn.

Cheers,

Frank