Question regarding dual pivot kit

Re: Question regarding dual pivot kit

Postby MOON » Fri Nov 29, 2019 9:27 pm

Where can I buy the ruby tipped screw for the 2nd pivot? Thanks .
Classic 4, 12"3d, hrx pulley, 3 belts, dual pivot, sds, Pneuance NP-2 Peunmatic footers, Lyra Kloes, Waynes Perifery Ring 3.8 lb, Stillpoint LPI , Simaudio 610 Evolution PS, Audio Sensibility silver statement cable, Tru lift & sweep
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Re: Question regarding dual pivot kit

Postby Votan » Sat Nov 30, 2019 4:15 pm

tom collins wrote:I recently had an in-depth discussion with a person whom I won't name, but is quite involved in the VPI world. I trust his insight. His suggestion was to not purchase the 2nd pivot. As you can see in my system description, I use the 12.7 arm. I told this person that what I hoped to get from the 2nd pivot was tighter bass. He said you might get that at the expense of treble clarity and that the drag of the pivot would damage the faceplate.

I would totally agree with the advice you received on the second pivot device.
In particular, after a debate I had with some other members of the forum in an older thread, where I expressed then my-theoretical is true-own reservations about second pivot’s issues in sound (and not only) effectiveness, and after the persistence of the above members to try it out because I would definitely see improvement, and because from my work I have learned to always confirm (or reject) with trial and error any of my theoretical concerns, I finally bought it and tried it.
20191130_193946[80761].jpg
20191130_193946[80761].jpg (21.44 KiB) Viewed 327 times

After some days of use and careful evaluation, and after I had diligently loaded second pivot device with 65% of the VTF, readjusted A/s due second pivot’s additional drag and succeeding azimuth equilibrium with the Ortofon test disk balancing the crosstalk right, left channel, in combination with "Votan tweak", my verdict for second pivot’s sonics is:
Indeed slightly tighter bass (however then I haven’t even buy the VPI periphery ring) but at the expense of a noticeable loss of freshness and crispness of high frequencies and the unipivot’s traditional immediacy and freedom.
In comparison, the use of periphery ring, without the simultaneous use of dual pivot, but in combination with "Votan tweak", has brought a better bass than the second pivot device, but also, it has not only re-brought the freshness and crispness of high frequencies, but it Improved them even more.
Some side, but no negligible effects were that:
1. The sliding plate of second pivot device, as it was glued on the dogleg, was not completely horizontal (and despite my efforts I never managed to level it), resulting in the azimuth constantly changing slightly, but decisively sonically, during the spindle wise movement of the arm,
2. The sliding plate was finally groove carved on, creating much more and the worst, unpredictably fluctuating drag.
3. After loading the second pivot device it was the VTF that needed once more readjustment.
4. Given that the factory central pivot is too much higher than the second pivot’s contact point to its plate, this is forming an acclivitous axis, which, according to the micro ups and downs of tonearm in corrugated records, causes continuous micro changes of azimuth.
BTW, the above 2, 3 and 4 problems are very successfully solved by the brilliant ideas and execution of the tonearm in following image
Second pivot assemply done right.jpg
Second pivot assemply done right.jpg (14.78 KiB) Viewed 327 times
Prime Signature/10"3DR/Finite Element(FE) platform/ADS/Lyra Titan/VPI Ring/WW Silver Eclipse 8 Phono Cable/Groove+ SRX MkII Phono Stage/Moon 740 Pre/Moon 820 PSU/ATC 100 Active Speakers/AQ Niagara IC/WW Silver Electra A/C,FE Ref Rack/RPG Room Treatm.
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Re: Question regarding dual pivot kit

Postby Mr_Putty » Sun Dec 01, 2019 3:17 am

To all the second pivot users, I have some questions for you. Have you considered using the A/S mechanism as a means to load the pivot? Have you polished the surface of the screw where it touches the plate? Have you lubricated the plate with something? Do you ever clean the plate? Is the plate screw reasonably tight and is the pivot mounting secure? I agree the design is in some ways not as good as the photo (?) posted. But if you have not at least considered the above you are not getting the best of what it can do. Unless of course the improved design shown is a real and sound verified improvement its just theory. Here’s another idea for users. Remove the sticky plate adhesive and use super glue instead. And maybe try a thicker plate... But I wouldn’t count the current design obsolete just yet! As Votan, myself and others have found, controlling the micro vibrations is very important to getting the best from the equipment we have. The second pivot may also act as a micro drain....if correctly implemented.
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Re: Question regarding dual pivot kit

Postby Brf » Mon Dec 02, 2019 9:32 am

Mr_Putty wrote:To all the second pivot users, I have some questions for you. Have you considered using the A/S mechanism as a means to load the pivot? Have you polished the surface of the screw where it touches the plate? Have you lubricated the plate with something? Do you ever clean the plate? Is the plate screw reasonably tight and is the pivot mounting secure? I agree the design is in some ways not as good as the photo (?) posted. But if you have not at least considered the above you are not getting the best of what it can do. Unless of course the improved design shown is a real and sound verified improvement its just theory. Here’s another idea for users. Remove the sticky plate adhesive and use super glue instead. And maybe try a thicker plate... But I wouldn’t count the current design obsolete just yet! As Votan, myself and others have found, controlling the micro vibrations is very important to getting the best from the equipment we have. The second pivot may also act as a micro drain....if correctly implemented.


I am not sure how to employ the A/S mechanism to load the dual pivot?

I’ve played with various jeweled and Si3N4 pivot points. In theory, a harder, smoother surface should provide less friction. I could not discern any performance difference between the standard SS, jeweled or Si3N4 pivot. I use the small Si3N4 grade 5 ball tipped pivot graciously given to me by forum member Letsmakeadeal because it makes sense to me.

I also tested the effect of lowering the pivot point friction by using a lubricant to see if it made an audible difference. I used molybdenum disulfide which is a dry lubricate used to seal microporosities that causes friction. I could not discern an audible difference. Note: The issue with using a wet lubricant for an extended period of time is that it will attract contaminants, therefore, the effects will be short lived and it will require constant cleaning and reapplication due to the simple fact that it is not in a closed system.

I have since abandoned my quest for reduced friction between standard pivot point and SS skate plate. As an aside, I now use the 12" gimbal Fatboy as my primary tonearm with the 12-3DR with dual pivot as my second tonearm.
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Re: Question regarding dual pivot kit

Postby Mr_Putty » Wed Dec 04, 2019 1:16 pm

Brf,
My use of the A/S mechanism to load the second pivot was an experiment that did not quite work out. I was attempting to compensate for the uneven force on the plate caused by the tonearm wire (which provides my anti skate force). The A/S from the tonearm wire gradually reduces the force on the pivot as the tonearm moves inward. For the experiment I simply moved the A/S thread (which was not in use) from the tonearm and taped it to the top of the arm barrel above the arm spike. My thread is a thicker, multi strand line I originally used instead of the standard provided fishing line. For consistent loading of the plate it works quite well. I do not notice any negative effects. But, consistent force was not my goal, so that is why I say it did not quite work out. However, it should (does) help to align the counter weight directly over the spike (which is ideal) and/or the mass of the arm side weights as well. This means the pivot needs less force from the side weights, again helping to keep the dynamic moving mass of the arm (more) centered. I hope this makes sense. I have not tested the setup with the thread mounted higher than the top of the arm cylinder. That might be worth trying.
My pivot plate had developed some roughness before this experiment. I applied some Ceratec liquid moly to the plate and noticed the roughness improved over time. Maintenance required might be a simple q tip wipe once a month. No big deal as I continue to monitor for condition.
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Re: Question regarding dual pivot kit

Postby Stringreen » Fri Dec 06, 2019 4:14 pm

If the 2nd pivot screw is a bit too loose, use the pink locktite. Its a very slight tightening of the screw...yet loose enough to urge it for adjustment.
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