Discuss The Viv Lab Rigid Arm

Here is the URL for a discussion of the Viv Float that took place on Audiokarma starting in 2015.  I don't necessarily agree with all comments, but a few guys have some interesting ideas.  Some other guys don't.

https://audiokarma.org/forums/index.php?threads/truly-straight-underhung-tonearms-for-hifi-use.662119/

I found a very interesting discussion of the Viv Float on Audiokarma, dating to 2015. Some of the discussants seem very knowledgeable and brought up many additional pros and cons. Worth reading for an interested party. I’ll post the URL here.

So I ask again, why are you so angry, Raul? This is a hobby. I bought a tonearm and reported on its sound quality here in a thread that is supposed to be about that very same tonearm. Take it or leave it. Meantime, I am having fun with it. You tried to mock me ("blah, blah, blah" was the way you put it) for not saying why the tonearm might perform well, so I responded with a description of my current thoughts, even though I had already done so before you "blah"-ed me. End of story. This is not the first instance in which you have become apoplectic when someone reports an opinion or an observation that does not comply with any of your many biases.  The best you can ever do in such cases is to suggest that the other guy "likes distortion" but it's "perfectly alright". 

Dear Raul, Please read one or two of my earlier posts wherein I speculate on the reason why a proper underhung tonearm might be worth a further thought.  To boil down what I already wrote, (1) although much is made of the extreme TAE, those very high numbers (by comparison to conventional pivoted tonearms) only occur at the extremes as the stylus traverses the playing surface of an LP.  For a half-inch or so on either side of the single null point (i.e., for a whole inch or more of the playable surface), TAE is within the same range as the maxima for an overhung tonearm.  Thus one would not expect to hear a problem, if one were to compare overhung to underhung in that region.  Moreover, the change of TAE from zero at the single null point to the maxima at the outermost and innermost grooves is nearly linear going from positive to negative (adopting the convention that "positive" TAE is TAE that results in a skating force directed toward the spindle, and vice-versa for "negative" TAE) and very gradual. Whereas, with an overhung tonearm, TAE is always positive and is changing up and down then up and down again, across the playable surface.  Maybe that is a factor too, and (2) perhaps the very significant (2X to 3X) reduction in the skating force seen with an underhung tonearm compared to an overhung tonearm is very significant for the performance of the cartridge, because the skating force is borne at the fulcrum of the cantilever and more so when AS is invoked.  All of this is speculation stimulated by listening and thinking.  No measurements.

My listening so far suggests that the Viv makes average or above average cartridges sound better than I expect based on prior auditioning in overhung tonearms, but it cannot make a mediocre cartridge into a top class cartridge.  Sometimes the Viv is only "as good" as a good overhung tonearm.  Sometimes it portrays an ease and sense of open-ness and low distortion compared to a good overhung tonearm.

You may now re-state your often repeated mantra that I "like" distortion.  Have at it.

Why are you so angry?

Mijo, I have to apologize. Of course you have every right to choose where to spend your bucks and to reject one innovative approach in favor of another. As you know, I waited to buy the Viv Float until we were in Tokyo, and at a time when the yen to dollar exchange rate is at an all time high favoring the dollar, which saved me quite a bit on cost.  I am kind of a high end cheapskate.

Mijo, with great respect, all I’m asking for is a thoughtful cessation of knee jerk negative reactions to the very idea of an underhung tonearm with zero offset. Your point about cost is interesting; you’d rather not spend on an underhung tonearm so as to save your money to buy a different type of tonearm that costs 2-3X more. Just spent 2 afternoons at CAF and didn’t see the Schroeder or Reed tangential arms on demo, but did see a TruGlider with Nasotec headshell sporting an optical DS Audio cartridge. That setup makes the Viv look old school.

As I’ve said before, I’d value your opinion if you would seriously audition an underhung tonearm. That would be a real contribution. The way forward in science, and even in this trivial pursuit of audio excellence, is to seek an explanation for observations that run contrary to one’s cherished beliefs, rather than to ignore surprising results. That’s all I’m trying to do here.

Interesting tidbit, I learned yesterday that Yamaha has been offering an underhung tonearm since the early 80s, as an extra cost option on their GT2000 and possibly standard on the GT2000X. The YSA-2. So the idea is not at all new. Nor was it categorically rejected by Japanese audiophiles, since all commercially available underhung tonearms emanate from japan. The YSA-2 is an entirely conventional tonearm for its day. Nothing odd about its appearance or functionality, and it can be mounted on any TT. Except it has zero headshell offset and is meant to be underhung. I want one.

On the MP500, I think the spec is for 100 Hz. You have to convert that to 10Hz by multiplying by a factor between 1.7 and 2.0.  So that would put the compliance at 10Hz at ~14 to 17cu, which makes more sense.  The VE database more often than not should not be trusted.  Or "trust but verify".

I’ve “discovered” that alignment is important, using the supplied template. I aligned for the first cartridge I auditioned on the Viv (Ortofon MC7500). Since then I’ve simply been swapping out different cartridges each mounted in a different CF headshell without bothering to re-check alignment. Recently I noticed that SQ with my Dynavector 17D3 was not up to snuff compared to a previous audition of the same cartridge. I had remounted the DV in a different headshell and the cartridge by chance was at the extreme end of the slots in the headshell. Thus alignment was off by about a centimeter too close to the spindle. This would place the null point in the runout grooves or even on the label. Correction of this error resulted in a huge improvement in SQ, 17D3 now sounding better than ever in any other tonearm.

Thx. It hardly was worth it to pay extra for DHL, especially since my cartridge is new and far from needing a new stylus.

Doggie and wrm57, Have you received your styli?  I ordered with 2-3 day delivery via DHL, but so far have received nothing. It's only 7 days, but still I am a bit concerned.  DHL is very prompt where I live.

I ordered a spare stylus too.  Thanks, Doggie.  Cheaper than the eBay vendor.

Big fan of MI cartridges. Own many of the great vintage ones but this is the first new cartridge I’ve purchased in a long time.

Right now I am flabbergasted about how good is the Nagaoka MP500 that I also bought in Tokyo last May.  Don't know why it took me so long to mount it for an audition (in my Triplanar on my Denon DP80). To those who don't know, because many refer to it as an MM type, this is a Moving Iron cartridge.  MP stands for Moving Permalloy, which is a little confusing because permalloy is magnetizable. Anyway, this is yet another great MI cartridge.

I may have to withdraw my statement that JE listened to an RS Labs tonearm and mentioned it sounded good.  I cannot find the post on VA. Thought I saw it yesterday.  John did acknowledge that the RS Labs has many fans; that's all I can find right now.  Sorry, John, if you are out there, which I doubt.

I am as familiar with JE's views as I am with yours.  Why can't you just go your own way, with my blessings, and know that there are other humans who think differently, on many matters related to audio, at least?  Like JE, you are replacing my comparison of the Viv tonearm to other conventional pivoted tonearms with a comparison of vinyl to digital.  I certainly readily concede that vinyl has more of various distortions than digital.  Happy?  Further, JE is calculating "distortion" using formulae that incorporate TAE as a determining parameter of distortion.  This is what is called a tautology.  Of course, if you make TAE a factor in the equation for distortion, then you will be finding that the more TAE, the more distortion. Like I also wrote above, in an earlier post, JE admitted that he liked the SQ of the RS Labs tonearm, based on LISTENING to it. 

I made an error in my post of 10/27 at 3:10 PM. The TAE of a 9-inch UH tonearm would not range between +9 degrees and -9 degrees, while passing through TAE =0, because the radius of an LP at outer grooves vs inner grooves is so radically different. Because the radius at the inner grooves is much less than outer, making for a tighter smaller circle at the innermost grooves, TAE at inner grooves would be higher than it is at outer grooves, even when you align for a null at the midpoint of the playing surface. That consideration is what leads to the very complex equations for TAE derived by Lofgren and others. You can see this easily in the graphs posted above by Intact Audio (Dave). John Ellison posted graphs showing TAE for a 16-inch UH tonearm over on VA, perhaps included in the thread I referenced.  His graphs also show the effect. This is why the template for the Viv puts the single null point nearest to the innermost grooves, 90mm from the spindle. 

Over on Vinyl Asylum, there was a congenial discussion of underhung tonearms back in 2018-19, in relation to the introduction by Yamaha of their GT5000 turntable which comes with a straight, underhung tonearm.  I kind of wish I knew then what I know now about the Viv, but you can read some thoughts on the pros and cons.  Interestingly, John Ellison, who is certainly a ranking guru, comes down on the negative side, but in an earlier post, not included here, he admitted that he very much liked the RS Labs RS-A1.  What I would say now to JE is that I am not comparing the Viv sound to that of hi-rez digital, which he often does with vinyl; I am comparing it to other conventional overhung tonearms.  And to my ears, the Viv might come a bit closer to the master tape/digital ideal of low distortion.

https://db.audioasylum.com/mhtml/m.html?forum=vinyl&n=1173526&highlight=viv+float&r=&search_url=%2Fcgi%2Fsearch.mpl%3Fforum%3Dcables%26searchtext%3DChoseal

My previous post was not meant for you or your comment, but of course you are welcome to comment. Your response reveals just how close-minded you are on this subject. That’s fine. My post was meant to elicit comments or ideas from others who actually want to think on this subject. Dave and I have been trading emails on this subject for the last few days, and he has some interesting ideas as well.  See if you can borrow a Viv tonearm and give it a listen.  Then come back and tell me what you hear.  You can send me a private email if you like.  Until then, silence is golden, "for say the least".

I don't claim to know in the scientific sense why the Viv tonearm sounds very good with every cartridge, but here is some food for though:

(1) TAE. While the Viv and all other underhung tonearms with zero headshell offset does exhibit much higher TAE than can be achieved with an overhung/offset headshell, there are some mitigating factors, even assuming TAE is a major determinant of high SQ.  For example, my 9-inch Viv would be expected to exhibit about 9 degrees of TAE at the outermost grooves and about -9 degrees of TAE at the innermost grooves, assuming the playing surface of the average LP is about 3 inches across (the radius of the LP from outer to spindle).  This is assuming you set up the tonearm such that the single null point occurs in the center or middle of the playable surface.  At that point, TAE=0.  Thus TAE is very gradually changing from +9 degrees down to zero degrees and then further "down" to -9 degrees near the runout grooves.  The change in TAE is linear (but on the arc of the stylus).  If you consider only the middle inch of the playable surface, TAE goes from about 3 degrees through the zero null point to -3 degrees.  This is about what you get with a well aligned conventional tonearm.  Possibly, the continuousness of the sound from the Viv has to do with the linear nature of the change in TAE.  Conventional tonearms generate TAE that goes up and down and up and down across the surface of an LP.  Maybe that is not so good, even though lower in magnitude than a UH tonearm.

(2) Skating. The skating force generated by the Viv and other UH tonearms is directly proportional to TAE, because the headshell does not add to the skating force.  Whereas, for conventional tonearms, the headshell offset angle is the major cause of skating PLUS the effect of any TAE.  It thus has been shown that a conventional 9-inch tonearm generates about 2.5 to 3X more skating force than does a 9-inch UH tonearm.  And just as with TAE, the side force generated by a UH tonearm has its maxima at the outermost and innermost grooves, but at the null point, the direction of the side force changes by 180 degrees, pulling the tonearm outward instead of inwards.  This makes the side force very low on either side (outer vs inner) of the null point.  Yes, we correct for the skating force of conventional tonearms with the application of AS, and we all know how imperfect that is. Moreover, AS is applied back near the pivot whereas skating happens at the stylus.  This puts a force on the fulcrum of the cantilever that may be a source of distortion in overhung tonearms.

These are my thoughts.  Raul says I cannot justify what I hear from the Viv in "audiophile" terms.  (I won't sully the word "scientific".)  But there actually are things to think about here.

I’m reviewing on line reviews of the tonearm now. There is a commonality of opinion about the sonic virtues, and I hear it the same way. Must be something to that. I earlier reported that the base weighs 2 lbs, so as to firmly locate the pivot. I was wrong; the base weighs 2 kg or 4.4 lbs.

So if you ever get to listen to the Viv Lab tonearm under conditions that are familiar to you from past experience, and if you can manage to divorce yourself from pre-formed opinion, I would be very interested to know what you think of it. Until then, you cannot add anything, because we know already about its theoretical shortcomings.

Yes, I now recall that you did mention somewhere in the past that you owned an RS-A1.  I've never sold mine, but I don't use it for reasons stated. However, it too sounds better than it should given its shortcomings when you compare it to conventional tonearms.

My test process is based on more than 40 years of listening to a wide variety of turntables (5 TTs up and running), tonearms, and cartridges, and on recent years of being able to listen to any of several turntables, each with a different tonearm and cartridge, using one of two different audio systems.  This enables me to make rapid transitions (I can move a cartridge between turntables or between two tonearms or between two completely different systems, for example, in minutes, in order to evaluate that cartridge in isolation. The same can be done with other elements of the chain.)  But such evaluation is always limited in the sense that it is always subjective. I do own and use oscilloscopes (Techtronix, Sencore), audio frequency generators (HP), meters of all kinds, and a laboratory microscope, which I most often use for diagnostic and repair purposes. I also have trained as a vocalist and even performed several times, back 10 years ago or so. We attend live music performances at least once a month and more usually 2-3 times per month in the DC area, where there are a plethora of great performers.  I am also a member/donor to the Kennedy Center, and we attend often.

This is all a useless argument between us.  I say the Viv Float sounds very good and has some characteristics that are near to uniquely good among tonearms I have heard.  I am interested in why it sounds good.  And in the process, I have come to doubt certain gospels of modern pivoted tonearm design and the origins of these "gospel truths".  In contrast, you say the Viv simply cannot be good.  Let's agree to disagree without disparaging each other's qualifications to have an opinion.  That's what you just did do, despite your follow-up claims to the contrary. 

Dear Raul, I often have a problem to figure out in what way you are questioning my opinions or abilities, because of the language barrier.  In this case, it seems you are saying that I am incapable of discerning what are to you and some others obvious issues with the Viv Float tonearm, because I don't have a "test proved process" to use as a basis for comparison.  Based on your past statements, going all the way back to the MM thread, I gather that you worked very hard to develop ways to test new equipment or program material by training yourself as a listener.  To my knowledge, you don't actually use test instruments to collect data, and you don't do a formal analysis of yours or anyone else's data to draw conclusions.  In the end, you rely upon your trained ears.  Perhaps you are exposed to quantitative analysis in some cases through your association with Jose'.  If so, I don't recall your ever bringing such information to Audiogon Forums.  All that said, and even assuming you are a better "listener" than I am, you have no experience with any underhung tonearm, so far as I know.  I have made the empirical observation that the Viv Float tonearm (and the RS-A1) sounds "good", better than one might ever expect based on theory as we have come to know modern tonearm theory.  And in some respects, the Viv is revealing in ways that other tonearms do not often achieve.  I have made no claim that the Viv is "the best" tonearm or that it is even "better" than good pivoted tonearms with overhang.  My 45 years of experience as a bench scientist tell me that when one gets a surprising result in an experiment, it is time to pay attention to those surprising data, because understanding what happened can sometimes lead to important alteration of one's belief system.  Here I am merely trying to understand why the Viv sounds so good with a variety of cartridges.  Since you have never heard it, you have no status in this discussion.  We all know in what ways  it defies convention.  That does not explain its goodness.  Meantime, you are welcome to read the discussion here, such as it is, but your criticism of my qualifications adds nothing.  At least I own and listen to the tonearm you so dislike, probably without ever having seen one in the flesh.

As to your inference that I cannot be a MUSIC lover, that's insulting.  So I see that you took your usual tack at the end of your post which is to suggest that my shortcomings are not my fault; they are merely due to a defecive "process".  Anyway, I posit that anyone who listens to music every day or plays an instrument, and who attends live concerts, and who says he or she is a music lover, IS a music lover. Most music lovers stay away from this Forum for good reason.

I found this interesting treatise on tonearm alignment in the context of a review of the Triplanar tonearm by Dick Olsher, which appeared in S'phile. If you read it to the end, his comments on the consequences of TAE are of note.  He also brings in skating force.

https://www.stereophile.com/tonearms/the_tri-planar_tonearm/index.html

Raul, I saw his comment, too.  Let the author defend it.

The phase argument was originally yours. I don’t buy its importance either. We agree.

"TAE affects all frequencies but primarily high frequencies the distortion is not harmonically related at all as the distortion varies continuously as does TAE. All frequencies have a horizontal component except those in perfect mono dead center."

I can agree that most frequencies have both a horizontal and vertical component in the movement of the stylus. It is simple-minded perhaps to suggest that "low frequencies" are produced by horizontal motion, but beyond that, can you further explain the rest of your statement that I quote here?  Thanks.

Pursuant to your use of a USB microscope, do you correct for zenith error using it? Or do you find that all your cartridges are perfect corrected for zenith?  I don't trust myself to see a one or two degree error in zenith using my analog microscope, and indeed in most cases I don't see error, but the ZYX Universe I own has a very obvious error by the same method.  Therefore I assume it's at least 3 degrees or more.  I have not inspected the ART7 that Dave twisted to correct for zenith, because I don't want to mess up his adjustment; the cartridge now sounds so good.

I did find some papers on this subject.  Here is a long post from Vinyl Asylum.  The author makes the good point that TAE affects only frequencies encoded in the horizontal plane (low frequencies), and he states that the distortion due to TAE is Harmonic in type. That may explain why if there is distortion due to TAE with the Viv and similar underhung tonearms, I (at least) do not find it objectionable.  Also, the level of distortion is inversely proportional to velocity, meaning HD will be higher near to the inner grooves. The math is complex and will take some time for me to digest:

https://www.audioasylum.com/messages/vinyl/43557/tone-arm-geometry-and-tracking-distortion-longish

Finally, the post opens the door to think maybe the skating force is more obnoxious than TAE.

Mijostyn, It does not behoove you to use the term "scientific" in this context to justify any of your thinking on the subject. Your approach fails the scientific method on first principles. You are operating within a belief system that starts out with TAE = bad. But I concede that neither of us has the actual data, apart from Intact Audio’s data, to justify any claims at all. I can say that when Dave "fixed" the zenith error on my ART7, it suddenly sounded better. He also measured the resulting TAE which reverted to the textbook look for a well aligned cartridge in an overhung tonearm. This certainly is consistent with the notion that TAE matters when zenith and the alignment according to accepted algorithms are both correct, for an overhung tonearm (with AS applied and azimuth set to 90 degrees, as well). Can you find a paper in the audio literature where the effects of TAE on the audio signal were looked at with a ’scope or some other valid method, that quantifies distortion of one kind or another? I cannot so far. This subject is only interesting if you approach it with an open mind. And I certainly don’t blame you if you don’t want to buy an underhung tonearm, but it does hamper your capacity to make a judgement on them as a class. Like I said, I took a flyer because the Viv has received near uniform positive reviews, because I could buy at a considerable discount in Japan, because I have also had good results with the weird RS Labs RS-A1, and because a major company (Yamaha) has seen fit to produce an expensive turntable with a built-in underhung tonearm. (I don’t use the RS-A1, because it is very finicky and most of all because it dangles the counterweight from the rear of the arm in order to place its center of gravity at the surface of the LP. This leaves the CW to sway like a pendulum, literally on off-center LPs, which cannot be good for the cartridge suspension. But the RS-A1 displays many of the positive good qualities of the Viv.)

Mijostyn, please do a little more thinking before erupting. Zenith error has an equally destructive effect on alignments whether you’re using a UH tonearm or a conventional one. In both cases you lose null points and TAE is exacerbated. But, come to think of it now, with a UH situation, there might be a point on the arc of stylus travel where zenith error by chance corrects for TAE, and you’d actually have less TAE (maybe even a null) at that moment. I wonder whether Dave has looked at that.

On the day Dave "twisted" my cartridge (Audio Technica ART7) to correct for its zenith error, using an electronic method, not guesswork, my ears immediately picked up to the effect of the proper correction. And Dave’s did too. It was quite obvious that the SQ had ticked up a notch or two. So, with an overhung tonearm (in this case, Kenwood L07J tonearm on my L07D turntable) I certainly can hear TAE errors. Currently in the Viv I am listening to my ZYX Universe. That cartridge has never been re-tipped. By visual inspection using my Olympus microscope, it has considerable zenith error in the mounting of its stylus, in that you can easily see it by microscopy. Whereas the two other cartridges that have been in the Viv (Dynavector 17D3 and Ortofon MC7500) may also have zenith error, but I cannot see it by visual inspection.

Raul, You and others have successfully equated TAE with "distortion" in the minds of most, without ever having defined what sort of distortion might result from TAE and its audibility, apart from phase distortion, which I think is trivial compared to all the other sources of phase distortion that are inherent to home audio systems, let alone to vinyl. What is needed is a serious study of this phenomenon where measurements are made. While we are at it, in the same study, skating force distortion ought also to be measured. Until then, your complete conviction that you alone are possessed of the "truth" rings hollow to me. Is your close-minded attitude any better than the behavior of the AHEE that you so revile? And by the way, worship of minimizing TAE at all costs is a basic tenet of the AHEE. That’s why we have 12-inch tonearms and several linear trackers where the cure is certainly worse than the disease, referring to LTs that use a noisy motor or gravity derived by dishing the platter, or a poorly designed air bearing, to drive the pivot across the LP, and LTs with stubby arm wands that maximize the deleterious effects of even small warps.

By the way, Dave was in my house and demonstrated the negative effects of zenith error, using one of my conventional overhung pivoted tonearms and a cartridge that was correctly aligned to begin with. (This was months before I purchased the Viv.) The improvement in SQ associated with correcting for the zenith error of the stylus mount was immediately apparent.

Barney, are you saying that the contents of this thread bear evidence that convinces you the Viv tonearm and other underhung tonearms are “worse than the disease” of antiskate? Or what?

FYI, underhung tonearms do generate a skating force except at their single null point. However, (1) that force is lower in magnitude than the skating force generated by overhung tonearms, and (2) the vector direction of the skating force changes from pointing inward to pointing outward, as the stylus passes through the null point.  This latter would make it tricky to design an AS device for an underhung tonearm. even if one were wanted.

Have you ever auditioned any underhung tonearm?

Or that music information would eventually be encoded in vertical as well as purely horizontal motion of the stylus, as was the case in the 30s and 40s.

Raul, When I wrote that the stylus should always ride down the middle of the groove, it was perhaps a poor choice of words for what I wanted to convey, which I then tried to capture better in my follow on statement.  Of course, in reality the groove itself, because of its tortuosity, friction, and Newtonian mechanics, will toss the stylus tip around quite a bit, and this is sometimes an audible cause of mistracking.  But Mijostyn was laying down ideal parameters that cannot be perfectly adhered to, so I added to his list of idealistic goals.  In an ideal world, the tonearm and cartridge would be massless and therefore not affected at all by groove tortuosity.

Who would argue with that description of the perfect tonearm?  Not I. I would add one more property to a list of the desired qualities of a perfect tonearm: Such a tonearm should elicit no eccentric side forces on the groove walls, as the stylus moves across the LP.  That is, the stylus should always ride right down the middle of the groove, to the degree that its own properties (compliance, etc) affect is tracking ability.  This is where most linear trackers fall down.

Raul, I over-reacted to your earlier remark. We’re all here to learn. And as I’ve said, I am in no position to make a final judgement except to say the Viv has no glaring audible issues compared to the conventional pivoted tonearms I own.

Sure. Whatever you say.  That must be why I also like the 3160.

Yes, maybe.  I still have more work to do that requires just listening. My opinion is that the special sound quality of this tonearm has more to do with the underhung geometry than with low friction.

Correct.  If you use the headshell supplied with the tonearm, it would not be possible to twist the cartridge with respect to the long axis of the headshell, unless you somehow modify the headshell.  However, the tonearm accepts all standard headshells, so it might be possible to use a conventional headshell and twist the cartridge at an angle so as to effect a "conventional" geometry, with the stylus overhanging the spindle.  Also, there exist a very few headshells that incorporate the offset angle into the headshell mount, meant for mounting on a straight pipe arm wand.  I think Garrard made a tonearm like that.  Such a headshell could also be used.

As to your first question, no, I have not removed the O-ring dampers from the arm wand.

Overhang geometry requires a headshell offset angle, else you get very extreme TAE and no null point anywhere.

Pindac, What I pointed is that in his interview posted on Youtube in Japanese but with English subtitles, Akimoto-san (inventor of the Viv Rigid Float tonearm) says his main goal was lowest possible friction. Hence the pivot floating on an oil bath. Just exactly why it is magnetic oil I still do not understand, but I would guess that he uses magnetic attraction to stabilize the assembly. Surprisingly, to me, he makes no mention of the underhang geometry in that short video. It might be interesting to note that when my son was conversing with Akimoto-san prior to my purchase, he asked my son why I wanted one.  By this I think he was genuinely curious about the genesis of my interest.

As far as I am concerned, I plan to continue to listen to this tonearm and to compare various cartridges for performance in the Viv vs in one of my conventional pivoted tonearms, using the same turntable and the same system in each arm of the study. I’ll post my findings as they happen, but I am not interested in arguing with anyone about the basic principles involved.  I have no reason to believe I could change anyone's mind, nor is that my main goal.

I found a video on Youtube that shows the pivot mechanism in action, totally removed from the shroud that otherwise makes it impossible to see it. The problem is there is only one view and no narrative. Just go to Youtube and search on "Viv Float tonearm", and you can find the video. The arm wand appears to be mounted on a rectangular platform that floats on the magnetic oil bath. Lateral motion of the platform appears to be prohibited by a raised lip around the edges of the circular oil bath. This physical arrangement conforms to my findings with pulling, pushing, or twisting the arm wand; it’s quite stable and quite low in friction. (I also found a video of an interview (in Japanese) with the designer, Akimoto-san.  It seems that ultra-low friction was a major design goal.  He does not say anything about geometry.) But to me, that is all beside the point. The point for me is the underhung geometry. Of course, it is impossible to separate the two oddities of this tonearm when assessing its sonic virtues.

I won't get into the meat of your post, but the pivot is not a "floating golf ball". Because it is totally enclosed, in order to keep the magnetic oil bath from spilling, I cannot really see what's going on there, but I suspect it is a constrained unipivot, constrained by magnetism. It's definitely constrained, because you cannot jostle the arm wand by twisting, pulling, or pushing, so long as you use reasonable force.

I don’t understand your last post.

Pindac, what you want to do, which is a logical way to compare overhang to underhang, seems to have been done by Intact Audio with a Schroeder tonearm. Perhaps Dave (aka Intact Audio) can say more. I think the headshell is held at an angle, on some Schroeder tonearms, by a single screw, making it easy to set offset to zero. Then you’d just have to move the pivot back away from the spindle to achieve underhang.

And my point, which apparently you are intent upon ignoring, is that the theory would predict that the Viv should sound grossly distorted (your term) compared to any decent overhung pivoted tonearm with headshell offset, and it does not, in my hands in my system to my ears. (And also apparently to many other pairs of ears.)  That proposition leaves aside the question of whether the Viv is better or not, compared to conventional tonearms. You are cordially invited to come have a listen, if you happen to be in the Washington, DC, area. 

From now on, I promise to credit Lofgren and only Lofgren with the algorithm that led to modern pivoted tonearm design. I don't care who gets the credit, and it has nothing at all to do with the issue at hand.  That is what I meant by having no dog in that fight.  It's an aphorism used by native English speakers. My real point is that his work was to solve the problem of how to minimize TAE with a pivoted tonearm. That's purely a question of geometry. 

Dear Raul, I was wondering what took you so long to comment on my report. I am trying to take the line of least resistance, which is this: If minimizing TAE at the expense of all other possible sources of aberrant forces was so vitally important, then the Viv tonearm ought to sound awful, or at least obviously worse than any reasonably well aligned conventional pivoted tonearm. But we have testimony from many others and now also my own testimony, that it does not sound awful or even worse than any of my four other conventional pivoted tonearms, using any of 3 cartridges that I have owned for a long time and heard previously on good conventional pivoted tonearms. I have no interest in convincing you of anything, but you cannot explain away my results by insinuating that I am not a qualified listener or that my equipment is not qualified to reveal obvious problems due to excessive TAE. (Well, maybe you privately think my Beveridge-based system is not good enough, but most would not.) As many others have tried to get across to you, "I like it", is not a trivial quality when evaluating audio products. Because after all, why are you using what you use? Because "you like it". (Yes, I know you believe you have developed superior listening skills that enable you to choose components that contribute least to "distortions". Standing on that high horse, you can always dismiss commentary that runs against your strong belief system.) Anyway, I hold you in high regard, but I am not surprised at your comments here.

Quibbling about who did what, Lofgren vs Baerwald, or whoever, is totally beside the point. If you think Lofgren should receive most of the credit for the idea of stylus overhang cum headshell offset angle, that is fine with me. I have no dog in that fight.