VPI 2nd Pivot for 3D

This is a response to Raul's contention that there is a "problem" with unipivot tonearms.  I am studiously trying to avoid the exchange about VPI and overhang.  I had read all of Raul's posts, watched the You Tube video (actually I saw it several months ago) and so on, but did not find it particularly enlightening or persuasive.  It falls far short of proof in any scientific sense that a problem exists with unipivot tonearms.  Yes they wobble a bit at first drop, but stabilize very quickly.  I have measured the tracking performance of several setups over a number of years using test records such as those from Shure and Ortofon among others.  Properly set up, the ability of any given cartridge to track well is not noticeably different when mounted in a unipivot tonearm.  This can be heard and observed using an oscilloscope.  That is a fact.  Cross talk for any given cartridge is not measurably diminished based on two arms of comparable quality, one double gimbal type vs. a unipivot.  That is a fact.  As any stylus wears I have carefully observed the patterns of wear for cartridges mounted on quality arms of various designs and have not observed any aberrations in wear patterns that resulted from unipivot arms.  This has been done using a Herr-Wildbrugg microscope, Model M3 or M5 starting in 1975 or 1976.  That is a fact.  So based on my years of experience setting up turntables (professionally 1970-1979), and the observable facts cited herein, I will state my opinion that there is no inherent problem with unipivot tonearms.  They are different and not to eveyones' liking, but functionally they are fine.  If you don't like them, don't use one, but you have no cause to malign the design.

Regards,

Bill

Dear @billstevenson : No malign action here. I own, owned and heard several unipivots including VPI and as you I know what I’m talking about.

Your " facts " about can’t prove that I’m wrong in my main " at micro levels unstability in any unipivot tonearm ". Reason is that those measures were not made it to prove it but to prove other targets.
We have to know what kind of measures where and how to achieve it to prove a specific subject. This time: at micro levels unstability in unipivot tonearm designs.

Your " facts " were as something of every day audio discussion, like this:

""" measures shows that these two amplifiers mearsures exactly the same but sounds different ! ! ? ? ! """

Problem there, that we don’t know what to measures to explain why sounds different. Same with your old " facts ".

In the other side you posted two facts that proves what I’m talking about:

""" my Prime single pivot tonearm was recently modified and significantly improved sonically by the addition of a second pivot """


""" It is doubtful that anyone who does this will decide after experimentation that the 2nd pivot does not provide a positive benefit. """



2nd pivot according my statements provides better stability. The only change in the VPI 2nd pivot is just the 2nd pivot that is what makes the difference.

The OP statements in his thread confirm my point.

Bill, remember that those huge forces at cartridge stylus tip during playback " makes " its works, the movements in the stylus tip has no precise pattern due that happens at random.

Here it’s not who has the reason, it’s only " common sense ". I respect what you posted but unfortunatelly does not proves what you think are proving. At least not if I’m wrong for this you need different " facts ".

Btw, you can make your research and try to learn ( for sure. ) what measures we have to do that can explain my point or better yet: that can explain why I'm wrong !. You was whom ask for facts due that those two stamentes posted by you were not enough for you be satisfied ! ? ! ?


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Well besides being a PTA to use the rs lab tonearm broke all the rules and I read nothing but great reviews.  Super high uni pivot and a rotating head shell.

When people start talking absolutes in this hobby, it tells you something.

Enjoy the ride
Tom

tomwh

When people start talking absolutes in this hobby, it tells you something

Agreed ... absolutely!  ; |

billstevenson

This is a response to Raul's contention that there is a "problem" with unipivot tonearms ... It falls far short of proof in any scientific sense that a problem exists with unipivot tonearms. Yes they wobble a bit at first drop, but stabilize very quickly ... Properly set up, the ability of any given cartridge to track well is not noticeably different when mounted in a unipivot tonearm. This can be heard and observed using an oscilloscope. That is a fact. Cross talk for any given cartridge is not measurably diminished based on two arms of comparable quality, one double gimbal type vs. a unipivot. That is a fact. As any stylus wears I have carefully observed the patterns of wear for cartridges mounted on quality arms of various designs and have not observed any aberrations in wear patterns that resulted from unipivot arms. This has been done using a Herr-Wildbrugg microscope, Model M3 or M5 starting in 1975 or 1976. That is a fact ... there is no inherent problem with unipivot tonearms. They are different and not to eveyones' liking, but functionally they are fine. If you don't like them, don't use one, but you have no cause to malign the design.

Bill, I couldn't agree with you more. I have heard some outstanding unipivot arms - truly exquisite - and Raul's insistence that there are "facts" that make them inherently flawed is just nonsense. There are reasons that unipivots endure in the marketplace, and performance is certainly one of them.

Nevertheless, I admit that I really don't care for unipivot arms and for that reason I've never owned one. It's a tactile thing with me; they just don't inspire confidence and don't exude the precision that I expect of a fine pickup arm. I've always indulged that preference, as I have my other audiophile preferences. The difference between Raul and me is that I don't insist that "facts" support my choice. It's just a preference. I don't feel obligated to convince the world that "facts" support my choice.