VPI Tone Arm Wobble when lowering and cueing the tonearm.

Discussion in 'Audio Hardware' started by Tony Plachy, Jan 12, 2018.

  1. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Location:
    Pleasantville, NY
    This thread is for VPI owners. I have been using a VPI Classic Direct TT with the JMW 12 3DR arm for almost two years now. Earlier this year I switched from a Benz-Micro Ruby3 cartridge to an Ortofon A95 (along with some other TT upgrades). The sound of the A95 is remarkable, however, I had a noticeable increase in tonearm wobble even when playing dead flat records. I use a Bosch laser level device to check both platter level and azimuth level, but that was not the problem. I saw Harry Weisfeld (one of the nicest people out there) at the NYC Audio Show and told him about my problem. He immediately I should get the new VPI Dual Pivot Assembly which I did. Installation was simple, however, getting the loading on the second pivot, the azimuth level and the VTF correct is an iterative process that takes a little while and some patience. Once you get setup, however, is is amazing. No more wobble and the A95 sound even better than it did before (sound stage image is even more rock solid than it was before). Highly recommended if your VPI arm has wobble problems and once again I cannot thank Harry enough for great TT's and great support.

    I suspect that my increase wobble problems may have been due to the light mass (6 grams) of the A95, since I did not have as much wobble with the Ruby3.
     
  2. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    Seattle, WA
    I'm guessing that your wobble was simply a mild case of resonance. And since that arm is a unipivot designs, it has more freedom of movement than do most arms.

    Adding the dual pivot is a good way to stabilize that sort of vibration. Plus it also gives the arm a much more solid feel.
     
    ggergm likes this.
  3. Mr Bass

    Mr Bass Forum Resident

    Location:
    Mid Atlantic
    There are tonearm -cartridge tables on the web to check various combinations. But yes the VPI tonearms are rather heavy and would have resonance issues with light cartridges.
     
  4. avanti1960

    avanti1960 Forum Resident

    Location:
    Chicago metro, USA
    I love VPI and their tables but it pisses me off that they don't ship the tables with the dual pivot assembly with the tables considering the price of the table.
    I'm on the fence about a new table and the prime may have been knocked down a few rungs.
    thanks for sharing Tony, many people are parked in an anti-uni-pivot camp for a variety of reasons i guess.
     
  5. Spinmeout

    Spinmeout Active Member

    Location:
    Australia
    X2.
    I'm not keen on spending $ on a table that i then have to tweak with add-ons to get it to sound it's best.
    It seems Vpi need to address these issues, it's put me off buying their product.
     
  6. Steve Hoffman

    Steve Hoffman Your Host Your Host

    This is bull crap. I have a Classic 2. Wobble really no big deal. What’s the friggin issue?
     
    mreeter, macster, teag and 3 others like this.
  7. Agreed. Bunch of pussies, I say, LOL.
     
    mreeter likes this.
  8. thegage

    thegage Forum Currency Nerd

    The wobble issue was raised by older owners or those with unsteady hands. Harry being the tinkerer he is came up with the second pivot. I don't understand why some people seem offended by it. It also has the unexpected benefit of, for some people, improving performance. Unipivots generally have a very open and pure top end and midrange compared to gimballed arms, but bass tends to suffer a bit as lower resonances aren't well controlled. The second pivot has improved bass definition as well as depth in my setup, plus, as Tony notes, soundstage is more stable, too.

    John K.
     
    macster and Guss2 like this.
  9. FLEMKE

    FLEMKE Forum Resident

    Location:
    CROOK COUNTY IL
    I fixed the wobble. MY Classic has the Eminent Tech. arm.

    Tim
     
  10. Subvet

    Subvet Forum Resident

    Location:
    Southern Maine
    I've had my Aries 3 for several years now. I have no wobble issues and thus far have had no interest in the 2nd Pivot. Also, I'm old and have shaky hands.
     
    mreeter and macster like this.
  11. psulioninks

    psulioninks Forum Resident

    Location:
    Kansas City, USA
    I just acquired a VPI Super Prime Scout about a month ago - took a day or so to get used to the uni-pivot tonearm. I am of the belief that the extra play in this arm allows to cartridge to better follow the cut of the grooves in the record. Pressings are not perfect, and it would make sense to me that this type of tonearm design is better equipped to deal with this. I liken it to the lean a motorcycle can achieve with its two wheel design over a vehicle with four wheels when following a curvy road.

    I will say, I've ripped about a half dozen albums so far with the new table and same cartridge as before (Nagaoka MP-500). In doing my headphone clean-up processing, I am hearing no distortion or mistracking at all. With my old table/arms, I could clearly hear more distortion (regardless of cartridge) here and there on almost every rip. Nothing real horrible and nothing you would hear through the speakers, but it was there with headphones on. And yes, I adjusted my cartridges to high heaven and could never totally eliminate it.

    Some people regard the Graham Phantom tonearm as one of the best ever conceived - it is also a uni-pivot design. Just sayin' that there might be something to this type of tonearm approach.

    To that end, I've had no issues using the new table/arm - it has been a sonic treat.
     
    mreeter likes this.
  12. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Location:
    Pleasantville, NY
    I agree that it probably a resonance, however, the 3D arm is very light. I use to use a VPI TNT-HR with a 12" aluminum arm which was much heaver than the 3D arm.
     
  13. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Location:
    Pleasantville, NY
    Don't let it put you off. You may not need the tweak if you do not have a light cartridge, if you do need it, it is not that expensive and easy to do.
     
  14. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Location:
    Pleasantville, NY
    Steve, In my case the wobble was enough that I was not always sure where the stylus would land when I cued it up. I recall that Michael Fremer said that the Continuum TT used a dual pivot as well. Can you comment on this?
     
    McGuy likes this.
  15. Mr Bass

    Mr Bass Forum Resident

    Location:
    Mid Atlantic
    Looking up the A95 it has a listed compliance of 13 (10-6 cm/dyne) so that would put the resonance at 11 Hz according to vinylengine given a 6g cart and 10g tonearm. That is in the good range but a bit close to the edge of the yellow caution at 12 Hz FWIW.
     
  16. Mr Bass

    Mr Bass Forum Resident

    Location:
    Mid Atlantic
    There may be a confusion between a wobble when lowering the tonearm vs a wobble after the tonearm is in contact with the record. Maybe a Gort should modify the thread title to make clear you mean when lowering the tonarm with cueing.
     
    macster likes this.
  17. Guss2

    Guss2 Well-Known Member

    Location:
    South Florida
    Everything said in this post is spot on. I never had a problem with the unipivot design at all, but I heard it would solidify the bass on my Avenger, so I went for it. For $150 it's a no brainer IMO, but I never ever felt the need to have it installed on my turntable.
     
  18. thegage

    thegage Forum Currency Nerd

    Fantastic arm. I used one for years on an HW-19, but eventually got tired of pump issues.

    John K.
     
  19. FLEMKE

    FLEMKE Forum Resident

    Location:
    CROOK COUNTY IL
    I have a JUN air compressor. I works without any issues. The ET 2.5 also has a higher psi. I generally use around 20.
    Tim
     
  20. McGuy

    McGuy Active Member

    Location:
    Chicago
    I have the wobble issue as well when cueing - just got my prime scount last tuesday, love it but the wobble is a bit disconcerting. getting used to it but might get the add-on.
     
  21. Hershiser

    Hershiser Well-Known Member

    It just functions differently then you are used to. Trust me you will get used to it, there is no need to modify for a dual pivot.
     
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  22. McGuy

    McGuy Active Member

    Location:
    Chicago
    I'm sure you're correct. just takes some time
     
  23. ggergm

    ggergm Forum Resident

    Location:
    Minnesota
    Both are right. It is a resonance in the tonearm. I experience with my Classic 2, both with the original metal and the 3D arms. It's easy to time the resonance to 2Hz, at least on my 'table, with the 3D tube and the smaller stability weights below the pivot, mounted 90° to the tube. The 3D tube normally comes with larger, heavier weights, which might change this resonance frequency a hair but those didn't fit on my base.

    Personally, I love the wobble because I know why it's there. It removes the arm's resonance from the audible range.

    Sure, the arm resonates at 2Hz, and it does something fierce. Unless you have a major issue, like the OP, who cares? It is straight forward mechanical engineering problem to design a system with a high resonance at one frequency and have that resonance roll off as the frequency goes up. You'll get some peaks at harmonics (double, triple, quadruple, and etcetera) the original frequency, but again, with good engineering, you can make those peaks pretty low. Ask any college level mechanical engineering student. This is pretty basic stuff.

    The arm has a lot of energy at 2Hz. It has much less at 20Hz. By the time we get to 100Hz, the energy the arm stores is very low. It doesn't add its sound to the sound of the music. And that's what I want.
     
    avanti1960 likes this.
  24. slovell

    slovell Forum Resident

    Location:
    Chesnee, SC, USA
    It does wobble a bit until it finds the groove then it's dead stable. Just a characteristic of the unipivot arm.
     
    Strat-Mangler and avanti1960 like this.
  25. avanti1960

    avanti1960 Forum Resident

    Location:
    Chicago metro, USA
    Does the wobble happen just during lowering the arm?
    If so, I can live with this.
    I was under the impression that the arm wobbled while playing- possibly worse with warped or off center LPs?

    If it doesn't rock / wobble while playing I can live with that.
     

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