Developing A List Of Tonearm Candidates For A SOTA Turntable

@audio_rd_uk : Thank you for your extensive comments on VTA, which I think were directed at me rather than @neonknight, since I opened the can of well-worn worms on adjusting VTA by asking about the dial on the Agile. I certainly appreciate the rigor of your analysis, but I do take issue with one conclusion:

My conclusion is, if adjustment each time works for you, doesn’t ’annoy you’ and you hear a difference, then have a L,M,H setting you can easily move to* then why not, but see if you do also have to adjust tracking mass because you are effectively altering the horizontal (and thus the gravity acting) distance from the pivot to the tip of the diamond, so would you want to be altering that as well?

This describes me pretty well: for each of my 7 tonearms, I have well-established presets in mind for standard LP weights, which approximately correspond to varying thicknesses. It’s easy to move between them per LP to maintain, for example, a level tonearm (which for argument’s sake only I will posit as ideal). So, is it not true that, if you set up all parameters with a level tonearm, maintaining a level tonearm by adjusting VTA actually retains "the horizontal (and thus the gravity acting) distance from the pivot to the tip of the diamond," and therefore the "tracking mass"? And in fact, not adjusting for record thickness would alter these parameters?

I’ve heard and read all the arguments by Fremer and other lovely experts as to why it’s impossible to hear minor variations from 92 degrees SRA, and the logic is compelling. I’ve tried and tried not to hear them with all my tonerams, setting VTA for, let’s say, a 160g LP and leaving it alone. It always sounds worse, and in predictable ways, for LPs of other thicknesses. Cue @mijostyn to tell me why I’m suffering from confirmation bias self-delusion :-). It’s an old specter that I did not intend to conjure again. I really only wanted to know more about the VTA mechanism on the Agile, which seems like it would suit my peculiar need.

@wrm57  Here I am. I was taking a nap. 

The problem is that most people have no idea where they are actually starting. The contact line has to start at 92 degrees. Even with a stabilized high power USB microscope this can be hard to see. In many styluses the contact line is not symmetrically in the center of the stylus. In the replicant 100 the contact line is parallel to the rear face. One has to know where the contact line is for the stylus they are using and measure from that. How one determines 92 degrees is with the stylus on the record at the correct VTF. One has to use a transparent protractor with 92 degrees scribed in very fine lines behind the stylus. If one is starting at say 95 degrees a fraction of a degree might make a difference. If you are truly starting at 92 degrees then a degree one way or the other will not make any difference. To prove this to yourself set the contact line at 92 degrees then have a friend change VTA or not and record your response for each position. I promise you will be amazed at the results. 

The Agile's mechanism is typical British simplicity and like the Schroder has a scale so you can return to previous positions accurately. It might be a bit fiddly in the Sota's tonearm well and I would not recommend trying to adjust it on the fly. 

I set VTA by ear using a known sample of records. My ears are more accurate than my eyes and I believe this would be true for most.

I sample thick and thin and from that testing I know exactly how must to adjust - for convenience I divide my collection into 180g and other ( thin ). Therefore I only run 2 settings.

Please note that you are not "adjusting VTA" for the thickness of records, you are trying to correct the VTA for the variation in thickness of each record.

Some early records are known to have been cut at odd angles, for these you either can ignore or again adjust by ear.

WARNING

Firstly, even though many of my tonearms have true VTA on the fly, I always lift the stylus off the record. I never adjust whilst playing. David Fletcher of Sumiko recommended this to me many years ago. Most VTA adjusters are quite brutal on the cantilever suspension and stylus if left playing.

Secondly, The Origin Live Agile has a fundamental flaw in that it has non offset bearings. This means that every time you adjust VTA on the Origin Live the azimuth changes. Another example of this are vintage arms like the Fidelity Research FR64S where I can hear the soundstage moving around from left to right and vice versa as VTA is adjusted

Note that if you are correcting VTA for a thicker record ( bringing the stylus back to the same angel as for a thinner record ), then the azimuth does not change.

Personally I could not live with an arm with non offset bearings for this reason because I hear quite large differences with dialling in VTA - I’ve measured a thou of an inch that I can hear significant differences.

@dover, that's really interesting. Thank you.

@mijostyn, it's hard to believe you ever nap!

@dover 

"Please note that you are not "adjusting VTA" for the thickness of records, you are trying to correct the VTA for the variation in thickness of each record."

There is enough question of the need for adjustment / correction or at least the amount of adjustment / correction, lets not split hairs over two statements which amount to the same thing. You are adjusting the VTA from what it was because of  change in the thickness of the record you want to play.  But you are only correcting it if you are without doubt that the angle you are setting it too is exactly the correct one. 

@wrm57  Actually no I was responding to @neonknight question of what I did on VTA.  Which I was giving a why rather than just an answer.  With regard to your point on horizontal and noting the caveat yes if the angle of the arm is set to the same each time then the horizontal distance would not vary.  But, with a two or three L,M,H as I described it then there will still be variation to the horizontal from LL to LH, LM to HM and LH to HH. So my point was only there is still going to be a range of tracking forces if using a 2/3 point setting without adjustment to the counter balance. Is it a variation that is enough to make a difference. It sounds as if if it would for some be far too much as they can hear an angle difference of 0.004 degrees.  Which when I have not seen a spec that reads below 0.1 of a degree is impressive to hear significant differences.