VPI 2nd Pivot for 3D


I just installed mine and discovering my old records anew.  I thought I knew everything there was to know on the original pressing of Fleetwood Mac's Rumers......but no - there's more.  You immediately hear a more solid bass, but then the dynamics hit hard.  It sounds like my amp is on steroids.  More cleanliness, - everything is better.  Very highly recommended.
stringreen
That's cool, have been looking at that and was looking for some feedback. Seems a fairly easy process.
same here.  easily worth the $150 for a noticeable improvement. 
Dear @stringreen: True unipivots are a " mess/nigthmare "  for pick-up recorded information from the LP grooves due to its real unstability at micro groove levels. Yes, I don't like it. The cartridge stylus needs must be fulfilled by the tonearm and " stability " for is perhaps the first and main target for any cartridge when it rides.

At our sigth we can't see that unstability, we think is steady at the grooves but it's not.

So, if your  VPI is no more an unipivot then what you have is a serious improvement in your listening experiences. Good.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
Thanks raul.....the 2nd pivot is certainly an improvement....probably as you say.
Where did you purchase the 2nd pivot?  Looks like a great idea!
Raul,
lndeed the VPI may now be as stable over warps as the Phantom.

It must be said that many people out there are still enjoying great satisfaction with "true" unipivots despite their minor foibles and idiosyncrasies :)

Enjoy the music!
truth be told, I never had any problem with either the 3D with or without the 2nd pivot or the metal VPI 10.5 arm with tracking any record I have.  I found the 3D a major improvement to the metal, and the 2nd pivot to be an even bigger improvement.  Some have voiced the opinion, that the single pivot arms "feel funny", but once lowered onto a record, the stability problem is eliminated. 
Dear Stringreen,
I think what Raul may be referring to is the eccentricity as the uni transcends a warp. If you videoed it then played it back in slow motion you'd see the cart wobble from side to side. My guess is that the effect might be worse with line contact and low compliance but the fact is that folk have been using regular unis for years and are unconcerned by rumours of eccentric behaviour. It goes without saying that in the general sense increased noise (for example) during the warp is often expected.
 Gimballed arm users needn't feel too smug because warps seldom remain in the same lateral plane as the cartridge but there is no active compensation other than via the cart's suspension or the cantilever. ;)

If there is a contest between the SL1200G & the Prime, this modification ups the stakes.
Happy listening!
Until I found this thread I wasn't even aware of this mod.  Just ordered mine and will report back on my experiences with it.  I haven't really had too much trouble with the unipivot, but the comments I've found suggest that the other pivot is a bit of an improvement.  
I didn't care much about the wobbly unipivot. For me the improvement of the 2nd pivot is mostly sonic - in imaging and dynamics - and also the fact that you can easily adjust the azimuth without altering the VTF.  
On a note of clarification when I mentioned the effect might be worse for line contact I was of course referring to the listening experience not the "wobble" effect ;) :)

If it is wobbling then spherical or elliptical might notice it less ;)
Dear @stringreen : """ the stability problem is eliminated. """

well, that’s what we think but: is it true?

The cartridge stylus tip is below a " tremendous " task where are generated hard and huge forces when ridding the LP recorded grooves.
Those forces come generated with almost at random directions/vectors that are transmited by the cantilever to the cartridge suspension to the cartridge motor and to the cartridge body and from here to the headshell/arm wand and tonearm bearing.

Those movements/vibrations are not a tiny ones but huge ones to generates unstabilities at the tonearm bearing where a unipivot can’t handle with aplomb and where that kind of unstabilities genrates colorations/distortions to the audio signal. This happens in a way down way with fixed bearing tonearm designs.

Take a look to these links on what the at each single groove where stylus cartridge tip has to " figth " and where each single groove is and has different path.
Additional to all those all the LPs comes with micro and macroscopics warps and all LPs are not dead centered mading the whole unstability subject more critical:

http://www.synthgear.com/2014/audio-gear/record-grooves-electron-microscope


https://www.google.com.mx/search?q=lp+grooves&tbm=isch&imgil=ktDEnuPAQUb1yM%253A%253BeuEapQR8NyxSFM%253Bhttp%25253A%25252F%25252Fwww.openculture.com%25252F2015%25252F06%25252Fa-stop-motion-of-a-needle-riding-through-lp-record-grooves.html&source=iu&pf=m&fir=ktDEnuPAQUb1yM%253A%252CeuEapQR8NyxSFM%252C_&usg=__Z4r0L19_k_EmY-GbwrRGAmPGugA%3D&biw=1366&bih=676&ved=0ahUKEwiZyteszZ3VAhXBJCYKHUFNCRoQyjcIMQ&ei=z6RzWdmmOcHJmAHBmqXQAQ#imgrc=ktDEnuPAQUb1yM:


https://www.youtube.com/watch?v=GuCdsyCWmt8


As always I’m not talking here if we like what we are hearing through unipivots or dislike, this is not the issue but to stay nearer to the recording that means we need to stay with distortions ( of every kind. ) at minimum and unipivots can’t help to achieve that main target.


I owned and own unipivots but as I posted I just do not likes because all those.


Can I be wrong?, just tell me. As I said, cartridge needs must be fulfilled by the tonearm design characteristics where bearing and damping make a paramount differences on the quality level of system overall performance. For me unipivots are out of the " equation ".


Regards and enjoy the MUSIC NOT DISTORTIONS,

R.



Raul....very few people on these sites are wrong or right.....Does one prefer Mozart to Beethoven?  All designs have something that can be pointed to with ridicule.  I've had many arms - (lets see if I remember some of them)...Grado Labs, ESL, SME V, Ortofon, Helius, Rega ..and so it goes.  They've all resided in systems that have changed as has the sound (my ears as well)....however, I have never been as satisfied with a tonearm as I have been with VPI. Should you want to hear mine, if you are ever in Arizona, let me know we can have a listen and some wine.
The cartridge stylus tip is below a " tremendous " task where are generated hard and huge forces when ridding the LP recorded grooves...
Those movements/vibrations are not a tiny ones but huge ones to generates unstabilities at the tonearm bearing where a unipivot can’t handle with aplomb...I’m not talking here if we like what we are hearing through unipivots or dislike, this is not the issue but to stay nearer to the recording that means we need to stay with distortions ( of every kind. ) at minimum and unipivots can’t help to achieve that main target...Can I be wrong?, just tell me.

Yes Raul you are very very wrong and again your flair for the dramatic and extreme are used to support your pronouncements of "fact" and wisdom. In fact the forces involved in LP playback are not "huge" ones at all but teeny tiny forces that are typically in the approximate range of fractions of a gram and it is for that reason that the entire rest of your summation here is as usual for you completely mistaken although you state it with such conviction and presumed authority that it may appear to be reasonable to he casual and uncritical reader and of course if Raul is consistent with his recent behaviors he will now respond by attacking the messenger with taunts and vindictive but frankly this matters not one tiny whit to me. 

Post removed 
To be entirely fair the pressure on a main bearing can be up to 50 tons/sq inch and stylus forces commensurately large but who's counting ;)
Dear @moonglum : Thank’s, you are rigth and yes: who’s counting but me. Good.

Ignorance is the " war’s mother " and that’s why I always try to improve my ignorant levels.

@moonglum in confirmation to your posts and mine here high-ligths from specific experts studies on the subject and its importance:

"""

The stylus tip, when in good condition, touches the groove walls at only two points. The entire weight of the stylus and the structure which holds it is concentrated at these two microscopically small points. When this concentration of pressure upon the points of contact is calculated, we find it to be approximately 26 tons per square inch. The walls of the record grooves are, of course, subject to the same pressure, but only for the fraction of a second required for a particular section to move past the tip as the record rotates. The stylus tip must travel well over one-half mile of surface each time a 12" LP record is played...with 26 tons of pressure per square inch. """



""" The most interesting photos to me described the "infinite" amount of force applied to the groove by the spherical and elliptical stylus designs. These designs effectively rest on 2 round contact points about 80%-90% of the way down into the groove. Since the contact points are rounded, the contact area is infinitely small, so no matter what the tracking force, the tracking pressure at the point of contact is effectively infinite. """



""" Getting back to the ripples caused by spherical and elliptical styli near the bottom of grooves, there seem to be 2 forces at work. The stylus tip gets warm on the two contact surfaces after only a few seconds playing. At that point you have a hot stylus pressing infinitely hard against vinyl and this can easily create substantial softening (melting is not required, in fact melting is not the mechanism that creates the ripples). After the stylus has passed any groove location the after-effect of the stylus bouncing merrily along in the groove causes the rippling. ..... But there are so many stretching, bouncing, musical, pushing/pulling pressure waves being generated, some driven into the disc and some being generated as the stylus tries to drag the vinyl along with it, that as the soft vinyl hardens again, it reacts in a resonant fashion. ""!"



""" From page 975 : "because of the small area of contact that exists between the stylus tip and the groove, the pressure against the groove wall can rise up to many thousands of pounds per square inch. For instance, if the wall receives 0.7 g of force applied through the contact area equal to 2 ten millionths of an inch, the pressure is 7726 lb/squ.inch. It has been experimentally shown that with such high pressures and forces of friction between stylus and the vinyl, that the outer skin layer of the record material melts as the tip slides over the plastic and then refreezes almost as fast as it melted. It has been suggested that since the melting temperature of vinyl is about 480 °F that the same temperature exists in the contact area. If the record material is metal, which happens when metal mothers are played, then the pressure increases to 20,000 to 30,000 lb/squ.inch, and the temperature can reach 2000°F because there is no plastic deformation of the groove wall. This explains why styli made of diamond, which is nothing more than carbon, literally burn up or wear out in a couple of hours when they are used to play metal mothers. """


In my past post I don’t speak of other parameters that can increment/modulate those very high forces that per sé increment the unstability problem in the unipivots during playback.


The recorded grooves were recorded at different recording velocities according the music information needs this has a direct effect on those forces that push the tonearm bearing, stylus tip shape has its own effect as the stylus tip wear through the time that between other things increment the friction between stylus tip and recorded grooves in encrement on those forces, skating has an effect too as the VTF and SRA that it’s changing almost at each groove due to LP imperfections. Of course that self cartridge tracking abilities contributes too.


All those very high forces affects any kind of tonearm bearing designs but on unipivots is the worst case.


@stringreen , I posted:


""" As always I’m not talking here if we like what we are hearing through unipivots or dislike, this is not the issue but to stay nearer to the recording that means we need to stay with distortions ( of every kind. ) at minimum and unipivots can’t help to achieve that main target. """


That’s what I’m talking about. As unipivots does not exist any single tonearm design with out trade-offs and each one of us choose which trade-offs are better choosed to be nearest to each one targets. Unipivots are out of question to achieve my today targets.


It’s nothing wrong with you because your system today fulfill your targets. Fine, that's what each one are looking for.

Btw, thank’s for your invitattion and you are welcome to come at my place in México city anytime.


Regards and enjoy the MUSIC NOT DISTORTIONS,

R.


Btw, as always the post of that person came only to " hit me " ( obviously with no success. ) with no single fact because has no facts. Pity.

You are most welcome, Raul.
I knew you were counting :) :)

Kind regards
Bill

 "When this concentration of pressure upon the points of contact is calculated, we find it to be approximately 26 tons per square inch... The most interesting photos to me described the "infinite" amount of force applied to the groove by the spherical and elliptical stylus designs....Since the contact points are rounded, the contact area is infinitely small, so no matter what the tracking force, the tracking pressure at the point of contact is effectively infinite...At that point you have a hot stylus pressing infinitely hard against vinyl and this can easily create substantial softening (melting is not required, in fact melting is not the mechanism that creates the ripples)....because of the small area of contact that exists between the stylus tip and the groove, the pressure against the groove wall can rise up to many thousands of pounds per square inch."


Raul thank you so much for regurgitating this little piece of fantasy I had forgotten about it entirely you did a fine job with cut and paste cut and paste cut and paste. Of course it is wholly fantasy as it's faulty "logic" is based on "infinite" forces and a contact area that is "infinitely small" if you do not see the humor in this then something was lost in translation and perhaps you should read it again rather than just cut and paste cut and paste cut and paste because of course in the real world of turntables used in Music Reproduction Systems there is no such thing as an infinite anything!


Also Raul if you are going to engage in cut and paste cut and paste cut and paste rather than going to the trouble of actually doing your own arithmetic then you should credit your sources and further when you cut and paste cut and paste cut and paste you might want to be a little less selective in your cut and paste cut and paste cut and paste and include disclaimer language such as one of your sources clearly noted at the top of its page that reprinted this "material":

"Shure makes no claims as to the accuracy of the information in the text."


However I do thank you for supplying what I think will be the biggest laughs I get all week it is truly priceless what you have done here and I now realize that you probably really don't intend it to be taken seriously at all but are using a subtle form of sarcasm/humor to entertain us. Very very nice work but of course if I am mistaken about your motives then you will return to insult me as you have elsewhere in this thread under which circumstances I am quite confident that the moderators in their esteemed judgement will delete your remarks again as they have so many times previously regarding your commentary here.


Infinite! Funny! I track at about 2.1 grams what about you, Raul??? :) :)  :) :)  :)  :) :) :)  :) :) :)  :) :) *G* *G* *G* lol!!!





Raul thank you again I am still laughing away over you're logic that relies on the assumptions of "infinites" to arrive at real-world conclusions about tonearm pivots. To help you develop you're own arithmetic model rather than relying on the flawed work of others, here are some steps to follow.

After measuring the coefficient of friction as ratios between pivot points and accounting for the pivot-to-spindle difference as a variance on the ideal transference of rotational convergence, integrate the realtime consequence of the stylus to groove vibrational interaction with the cantilever assembly to arrive at a  deviation (from the theoretical ideal, of course) of the frequency output seen at the phono preamp input while carefully accounting for the impedance and resistive effects that the cables themselves introduce to the ac signal.  The resulting schemas can form the basis of the conclusion regarding the pivot friction forces that influence unipivot tonearms and this will help you synthesize extensible paradigms but please remember that the results you obtain will be limited to the specific example of tonearm that you have so carefully measured.

I do hope that you will share your results with this group so that we verify your calculations.

Clearthink,

You realise you've just given Lew a brainstorm... :D :D

Like the Krell knowledge base, it'll take him years to decipher that ;) :D


https://www.youtube.com/watch?v=3GSd92zgqAs


Dear @moonglum : There are several audio subjects we are not totally aware of or that just we need to remember it.

Cartridge/tonearm/LP relationship is the most important subject in the analog experience.

Those very high forces generated in between puts its own " signature " on what we are listening.
It is not only that ( for me ) unipivots are forbidden tonearm designs but at almost the same critical importance is the tonearm necessity of been perfectly damped through its design or other way: forbidenn.

We have to remember that all those generated vibrations/resonances/errors between the LP/cartridge/tonearms continuously are generating feedback through that " circuit " adding complexity to the whole main subject.

Good that you had that " number " at the tonearm bearing.

Over the net exist " formidable " scientific information. AES/BAS are some sources about but I can see that in your country you already was aware of all those.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Dear Raul,

The report you published is the first I’ve seen that confirms my long-held belief that diamonds “burn” more than they “wear”. Many thanks for that! :)

 

The importance of the “message” rather than the messenger is the main thing. People may differ on what they regard as the perfect analogue medium or how to achieve it but it is gratifying that vinyl records are still being celebrated today regardless of those differences.

 

Diverse solutions are also something to celebrate.

It shows that we’re still alive and thinking even if there are downsides and compromises. :)

Best regards,

Bill

For those seeking a more "stable" platform for their cartridge that combines all the virtues of 3D construction (non-resonant, tonal purity) and unipivot design (extended treble, lots of inner detail) you may be interested in the new VPI 10" gimbaled arm that is a (superior) variant of the one that will appear on the Levinson table. I had a unipivot 3D-10 for about a year and it performed extremely well on my vintage Scout. I was able to work with Mat and Harry to outfit a "curvey" Scout plinth with their new gimbaled 3D-10 and can tell you that it has all the virtues of the unipivot but improves upon the bass response (deeper and tighter), imaging (tighter focus) and resolution (more inner detail and less distortion). The sound has that elusive combination of a relaxed presentation with extraordinary detail that I have heard in a few select top tier vinyl playback systems. I posted pictures on the VPI forum for those interested in taking a look....

http://www.vpiforum.com/viewtopic.php?f=11&t=9306


Actually, you’re right the gimbaled arm has virtues that the unipivot doesn’t and v/v. The reason the 2nd pivot attachment to the unipivot was released is because the 2nd pivot combines the advantages and none of the disadvantages to the competing designs....so said Harry.
Dear @moonglum : If I remember the latest information about was by Dr. A:J Van denHul who measured 160° celcius between the stylus tip and groove.

In the other side the best confirmation  on the critical importance for tonearm true stability bearings to " avoid " all those huge developed forces are the listen experiences by @stringreen and @dodgealum whom owns the true unipivots and compared against the quasi-unipivot ( stringreen. ) and the gimballed one VPI model. Both very precise in the improvement levels.

That's the same experiences audiophiles had when changed from the original Graham tonearm ( similar design to the unipivot AC 3000. ) design to the Phantom ( I think you own this model. ) or from the DP-4 ( similar unipivot design to Highphonic. ) to de DP-6/8 or even the Cobra.

Good that after so long time some tonearm designers took in count the terrible unipivot disadvantage due to that unstability because this is what the cartridge does not needs and is not asking for. We always have to understand the cartridge needs at microscopic levels because almost all comes from there.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.


Indeed Raul, there's no substitute for a satisfied user endorsement :)

It would be interesting to see a list of all designs that included a measure of compensation.

VPI have now joined this club and you mentioned the Graham series. I believe Frank Schroeder has also had a try at defeating the "Achilles heel".

Interestingly MF is no longer using a Cobra on his Continuum. Those duties are now shared between a 4-Point and the Swedish "SAT" tonearm ($28K - see here) :

https://www.stereophile.com/content/swedish-analog-technologies-tonearm

....which must make it a contender for the most expensive on the market?

Happy listening,

Bill.

Dear @moonglum : FS. is a great designer and I forgot his tonearm designs.

I experienced the Kuzma 4-point and is very good design and can understand why MF use it. In the other side: can any one justify against quality level performance a 28K on tag for a " simple " tonearm?

Well, maybe I don't know.  Coming from a professional reviewer puts me ore doubts than certainty about.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
"If I remember the latest information about was by Dr. A:J Van denHul who measured 160° celcius between the stylus tip and groove"

This is another "funny fact" from Raul that is like his claim that VTF is "infinite" because the contact area of a stylus is "infinitely small" it sure must be a funny world Raul lives in with these "theories" that are "fantasies" that he insists are "facts." Such confusion about such basic things really makes me wonder whether Raul is aware of this confusion he loves to share as "facts" or whether Raul's problems are really much deeper than that in which case we should be feeling very sorry for Raul!
Dear Raul,
Perhaps the moderator should step in at this point...  ;)

Yes, I've only heard the SAT tone arm via 320kbps needle drops versus CDs etc but it presents a persuasive argument even if unattainable for the many. If there are hidden distortions in there I like them! ;) :)

BTW before I took early retirement, our thermal engineers constantly used thermal imaging cameras to analyse circuit boards and develop thermal maps. It's probably what VDH used to get an approximation of the stylus interface? They could be quite handy for troubleshooting too.

I recall an EMI chemist commenting on one forum that the melting point of some vinyl formulations was as low as 112C (I know, a bit nerve wracking for the steam cleaning brigade;)
Best regards,
Bill
Dear @dodgealum : This video is from the Levinson tonearm and I hope that what we see between the the second 10 and the 16 second is not what happens with that fixed bearing tonearm manufactured by VPI:

https://www.youtube.com/watch?v=iTTLM9gPU9o

Anyway, the video is a very good fact that confirm what that those huge forces makes with the cartridge/tonearm and why unipivots are out of question.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Dear @moonglum :  Handbook for enginners: "  "It has been experimentally shown that with such high pressures and forces of friction between stylus and the vinyl, that the outer skin layer of the record material melts as the tip slides over the plastic and then refreezes almost as fast as it melted. It has been suggested that since the melting temperature of vinyl is about 480 °F (248 °C) that the same temperature exists in the contact area.”

You can confirm here the fact you was thinking about and at the same time other additional fact that confirms about those very huge forces generated down there. 

Btw, I can tell you that my very high ignorance levels brought me to a extreme high frustration levels.  Never mind, such is life.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
@moonglum : "  Van Den Hul states :

"But the most important thing is record wear. I measured temperatures using a thermistor with a thin wire around the tip. A conical tip went up to about 140 deg C, but my one was 60 deg. I would like to come down further, but this was the lowest possible value."


R.

Hi Raul,
I agree it is confusing. I recall looking up the data at the time and the "248C" figure was known to me. I was somewhat surprised back then but given how easily vinyl warps next to central heating radiators I dismissed 248C as one possible value depending on composition and state i.e temperature at which it becomes fully liquid as opposed to becoming "soft"?

Clearly it does need to be a lower figure than 248C in order for the melting/reforming thesis to work?
Now you've got me wondering again. :)
I'll try to find the reference for you ;)

Best regards,
Bill

Hi Raul,

Found it. It is anecdotal but then most things on Forums are :)

If you are in Windows, do a CTRL F and search "Coxybabe"....


https://forums.linn.co.uk/bb/archive/index.php?thread-29073.html

All the best,

Bill.

Dear Raul,
VDHs measurements of his own stylus seem to be defying the "natural order" of things by lowering the junction temperature to 60C. If true, one wonders if instead of vinyl reacting in a malleable way the stylus dislodges chunks which then fall into the groove causing further problems ;)
Of course 60C must presume perfect azimuth of his line contact(?) stylus. One would assume that misalignment would undoubtedly push the temp even higher than a perfectly aligned conical stylus's 140C, leaving the user in the same state as he was before :)

If VDH is successful with his low temp approach, the unit price of Last is going to rocket :D
Best regards
Bill

Dear @moonglum : Great facts/information. As I said exist formidable audio information all over the net and comes from experts.

Facts that can makes a paramount differences in each one of us ignorance levels, obviously all of us can improve our knowledge levels, skills and tools !!

Btw, @dodgealum , you own the Levinson/VPI tonearm and in the " you tube " link I posted here we can see a way " terrible earthwake " down there that if it's happening then exist something really wrong in that tonearm design.

Would you comment about?, appreciated.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.


Dear friends: That " terrible earthwake " is unaceptable by any audio standards and that's is what happens with all unipivots or quai-unipivots.

A very well regarded tonearm unipivot with a tag over 25K states in its site:


"""  it is subjected to the mechanical vibrations from the musical source (the stylus moving in the groove), and it should before all not damage them and let them interfere with the electric signal coming from the cartridge. Each of the tonearm's constituents carries a crucial responsibility in the transmission of these vibrations, so every element, down to the smallest screw plays an essential role in the resulting sound. Those who claim that mechanical devices don’t have a sound don’t understand the nature of sound. Everything has a sound. Every piece of matter enters in vibration when it’s moving and that is what gives it its distinctive sound. """

seems to me that the tonearm designer of that company has very clear ( ? ) that critical subject and ( for me ) is just out of my mind why he choosed an unipivot design to fulfill that statement when it can't do it.

Btw, there is no single advantage in an unipivot design. What we listen through it are only higher distortions and that's all. 

Cartridge needs " perfect " stability in a tonearm with NO earthwakes.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
@rauliruegas could you explain the problem you have with the video you posted and why this has any bearing to the merits of a unipivot design. As I see it the video shows the forces acting on a cartridge at needle drop, and speak more to a poorly damped lift/lower mechanism then anything else. Secondly the arm in the video is a gimballed design not a unipivot so the video has nothing to say about unipivot design. Anyway some more details on the issues you are trying to refer to would be helpful
That is creepy! I would have sworn that was a unipivot touching down. ;)
I agree that a cartridge must negotiate a very poor road to travel....in Arizona, some of the car roads are also very poor, yet my car suspension system compensates for that leaving a pleasant riding experience. My cartridge also has a suspension system.....I hear the music very well.
I suspect what we may have witnessed in the video is an example of the "filmmaker's art". Just because Daniel Craig appears to jump off a bridge in 007 movie doesn't mean it is actually him doing the jumping! ;)
They may have inserted stock footage of a unipivot in action? People more familiar than I with the product range might be able to identify what's going on here more accurately?
To avoid this argument gaining further momentum, perhaps someone in authority at Mark Levinson or VPI would care to address the Forum and explain what the "offending" frames in the video represent, if only as an exercise in damage limitation? ;^)

Here's the link to the video in situ.
http://www.marklevinson.com/productdetail/~/product/no515.html

@moonglum may be correct as the video of the needle drop is of an Ortofon 2M Bronze (I think) whereas the 515 ships with (and is seen later in the video) with a Cadenza Bronze which looks quite different

all in all this is coming off like amateur hour by Mark Levinson and VPI
Dear @folkfreak : It's obvious that the tonearm in that you tube video is an unipivot design or a gimball one with a severe extreme bearing damages.

The video is a " dramatization " that helps to understand what is happening in continuious way at microscopic stylus tip during play of any cartridge in any unipivot tonearm design and in little lower way in quai-unipivot ones.

Forces are so huge that gravity alone can't correct it.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

My guess is the artistic director decided on substituting with a unipivot because it looked less boring than a gimballed one ;^)


Is it possible though, Raul, that even gimballed arms aren’t entirely "torsionally stable"? The movements may be small but real due to a necessary amount of bearing "play". I remember, decades ago, Syrinx used offset bearings to try to improve this and resonance behaviour.

In fact I used to own a Syrinx PU2... ;^)

Not surprisingly the LF performance really was something to write home about :)

"It has been experimentally shown that with such high pressures and forces of friction between stylus and the vinyl, that the outer skin layer of the record material melts as the tip slides over the plastic and then refreezes almost as fast as it melted. It has been suggested that since the melting temperature of vinyl is about 480 °F (248 °C) that the same temperature exists in the contact area.”

Thank you again very much Raul for supplying the biggest laughs I am getting this week this claim is absolutely astoundingly extraordinary and it is obviously intended NOT to be taken seriously perhaps as a lesson that we should not believe everything we read or perhaps as a lesson that "fake news" is not a new phenomenon! It should be patently obvious to anyone with even a limited understanding of thermodynamics or who even knows how to operate a common household thermostat that a record does not go from room temperature to melting to freezing (!!!!) all in an instant simply because a stylus passes over it. While I suppose a conjecture could be made and it is only a conjecture that a stylus may heat a record due to friction but to suggest that it will melt the vinyl and then FREEZE It is beyond silly it is so funny thank you, Raul!

What would be really great is if we could capture those FREEZING temperatures and conduct them in such a way to offset the heat produced by our tube amplifiers! That would be great especially in the summer months Raul will you please use Google to see if that can be done and then cut and paste cut and paste and cut and paste and cut and paste cut and paste and cut and paste and cut and paste and cut and paste some more and share that with us??? Thank you and thanks again for the big laughs you made my day your stuff gets funnier and funnier.
The many versions of VPI arms that can use pivot damping fluid are very stable, and have no wobble.

I have heard the 3D arms, and they have nothing over a properly setup metal VPI arm, IMO!

The 3D arms look cheap!

The new second pivot "supposed improvement" is simply "expectation" bias - nothing to shoot out about.

stringreen is a long time VPI shill!

I like VPI, but I am not "mad" about all their newer products.
Don - you do not know what you’re talking about. I’m sure you are not a VPI fan, but if you don’t know what truth is, you shouldn’t post to steer subscribers in the wrong direction. Damping fluid in the metal VPI arms can be useful if you want to tune out a wart in your speakers, etc....in truth the damping fluid in a high end system reveals a closing in of the soundstage. Even with the damping fluid, the metal arms wobble.The metal VPI arms are very good, but the 3D’s are exceptional....ranking with the very best, even if they too wobble. If the look of the 3D is not pleasing, you can always glue diamonds to it....if the arm breaks, there is the VPI team that will readily repair/replace the arm. The 2nd pivot on the already excellent 3D that does not wobble,will make you want to re-listen to your records. I am a long time purchaser of VPI. I have a Supersoutmaster/rim drive/SDS/3D/2nd pivot. I even have one of their black VPI polo shirts that Harry sent me after helping me with an issue.
Dear @moonglum /friends: Torsianally stable?,  any tonearm suffers from that torional huge forces but the unipivots are where affects in the worst way to that very hard cartridge job.

In any cartridge mounted in any unipivot tonearm design combination first than all puts the " possibilities " to be nearest to the recording really far away.

That item combination is more an acrobatic act  that a listening experience. Unfortunatelly, that acrobatic act is made it with no real success.

We only have to think the total unstability that persé has any cartridge that rides through that very tyny stylus tip dimension and at the other extreme ( unipivots. ) side an inverted " stylus tip " that function as the pivot.
It's imposible to have any kind of stability in between, a stability that's a must to have for the cartridges can makes its job.
Even in static way an with the stylus tip in the LP with the TT spining exist no real stability. Imagine when in true motion ridding those grooves with all those  huge ( every direction ) generated forces ! ! ! 

Remember that I'm talking on what we like when listening to unipivots.

Btw, damping can't disappear the unstabilities at microscopic stylus tip as pointed out Don.

Even, in the VPI case, its design comes not caring very seriously about the needs for anti-skate.

I think that unipivots were and are designed because are easy to design, manufacturer and assembly. Additional comes with low market price. Well not so in the price subject when exist unipivots over 20K and there are audiophiles willing to own it ! ! ! Incredible.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.