Developing A List Of Tonearm Candidates For A SOTA Turntable

@neonknight  P.S. I note you had used a Verismo before you got the Agile and this has the same Multi Wall Carbon Nanotube technology (MWCNT), developed on the Verismo. They now use this on the MC Diamond which I have on my latest OL Deck with the older MC Anna Diamond being the one I originally tested above and having the less sophisticated suspension material. That being based on the fact that all else being equal the Diamond was significantly better than the Anna Diamond.  On a quick look I cannot see Ortofon noting on either the Verismo or the Diamond the "23 degrees = 90" though "92.1 being the potential optimal" thus requiring nearer 25 degree VTA.

Whether that is because they do not think the 92.1 deg is applicable to the MWCNT I do not as yet know, perhaps there is a reference elsewhere.   I just wanted to note this because when I changed to the MC Diamond from the Anna Diamond, I just checked the quoted spec was the same swapped, tested force and played with an immediate improvement.

I will see if I can find anymore references on this 23/90 deg vs 25/92.1 deg in case this has altered with the change in suspension material.

But if it is up to 2 deg range 90-92.1 for finding the 'optimal'  also that approx 1mm of height adjustment at the pivot is 0.25 degree at the stylus then my adjustments above for 180g to UHQR were no more than 0.5 degree within the MC Anna Diamonds quoted at 2 deg range.       

@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!