The CORRECT way to install VPI Dual Pivot on VPI unipivot arms
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- Опубликовано: 30 июл 2024
- Many audiophiles have tried to install the VPI dual pivot assembly on their VPI unipivot tonearms but few of them have it installed properly. If installed with too much stiction on the horizontal freedom of the arm, the dual pivot will actually make the sound of the arm worse, not better - as it certainly should and can do. Watch this video to learn how to get it done well and enjoy the sonic improvements for yourself.
Learn more about analog optimization on the WAM Engineering website's video page: www.wallyanalog.com/videos
Very cool J.R.
I use a synthetic sapphire ball bearing on the tip of the set screw to minimize wear on the glide plate. I believe Oz Martinez can provide them. I got mine from Joe Pittman who recently passed away, sadly.
Thank you for that! I’m sure that is a better long term solution.
Aren't we defeating the point of the uni-pivot by having a pin riding a plate. The only true uni-pivot is a horizontal uni-pivot not vertical. Well it would be better to have two magnets opposing each other at least there's no contact and more stable if correctly done
The dual pivot addition only helps the arm to act as a stable, rigid platform for the cartridge and thereby become more effective at its job. It doesn’t turn the VPI arm into one of the “greats”. The magnetic mechanism mechanism you mention is very ineffective at maintaining rigidity within several hundred microns from the mean (relaxed, neutral) position. Since audible groove perturbations are easily sub-micron in size, this freedom that a magnetic stabilization mechanism offers becomes an opportunity for the arm to rob (or re-deliver!) energy from the cartridge. That is not what we want for optimal performance.
Dual pivot added friction leaves more performance on the table than the arm in standard form. Plus, you have to constantly monitor its performance. No thanks.
Hello @michaeltriolo2360. Yours is a reasonable first reaction, but now let's put it into perspective.
We have to first consider WHY we care about low horizontal friction in a tonearm and then do the math to see why it is not a concern in this case. The ONLY reason why we want low friction in a tonearm is to ensure the cartridge damper is symmetrically compressed. Everything else - such as avoiding skewing the cantilever/stylus, uneven groove wear, groove skipping, sibilance and mistracking - are only SECOND ORDER PROBLEMS created by asymmetric compression of the damper.
Now, the damper is subject to a 6:1 lever arm as I explain in my other videos on horizontal force. So, if the WallySkater measures that the introduction of the Dual Pivot increases the horizontal friction to 3%, then: 2 gram VTF * 0.03 = 0.06gm horizontal force at the stylus due to the dual pivot friction. Then, 0.06gm * 6 (lever arm) = 0.36gm (+ AND - on either side of the damper) becomes the asymmetric compression force.
After this step can come a long study into what that 0.36gm force does to variable compliance across the damper but there is no room for that here. Suffice it to say that this force is likely a lot less than the error MOST people have their anti-skating misadjusted at (anti-skating, of course, can cause the same damper compression asymmetry).
So, we don't have to worry about a very small degree of frictional force, but if it is not measured and controlled, it certainly can QUICKLY get out of control and start robbing the performance of life and energy, shrinking the soundstage and ultimately causing sibilance, mistracking, etc.
@WAM-Engineering it may be okay for a few weeks or months. As you stated, the second pivot will begin to wear, and I believe slight dust or dirt will increase friction. Seems like it's more trouble than it's worth. This is exactly what pushes people away from vinyl playback.
@@mjot2360 CORRECT! This is clearly a risk, which is why you should re-measure horizontal and static forces every six months or so on any tonearm, for that matter.
YES - I also agree with you about the inconvenience. For those of us who want to get every last iota of information out of the grooves, it IS extra work - certainly compared to the indisputable convenience of digital. BUT...for those of us willing to put in the extra effort, we get paid many dividends in the sonic experience.