not another 2nd pivot question

Re: not another 2nd pivot question

Postby spinblackcircle » Wed Oct 25, 2017 1:05 pm

Genius! :ugeek:
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Re: not another 2nd pivot question

Postby Stringreen » Wed Oct 25, 2017 4:13 pm

no - blutack is not needed. ..just rotate the rear counterweight counter-clockwise to put additional pressure on the 2nd pivot, or clockwise to decrease pressure on the 2nd pivot. This will not disturb azimuth which is set with the adjusting screw (actually the beauty of the devise.) In the installation of my 2nd pivot I had to increase the pressure to be absolutely sure the azimuth adjusting screw maintains contact throughout the arm's travel.
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Re: not another 2nd pivot question

Postby Johnny » Wed Oct 25, 2017 4:58 pm

Stringreen wrote:no - blutack is not needed. ..just rotate the rear counterweight counter-clockwise to put additional pressure on the 2nd pivot, or clockwise to decrease pressure on the 2nd pivot. This will not disturb azimuth which is set with the adjusting screw (actually the beauty of the devise.) In the installation of my 2nd pivot I had to increase the pressure to be absolutely sure the azimuth adjusting screw maintains contact throughout the arm's travel.


Sorry, you missed the point completely. The discussion is about how much load should be put on the dual pivot, not how to load the dual pivot.
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Re: not another 2nd pivot question

Postby elader » Wed Oct 25, 2017 7:12 pm

the blutack (or in my case, the playdoh) stuck opposite the pivot precisely unweighted it, thus, with it removed, there was two grams of force on the second pivot point.

happy Eric.
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Re: not another 2nd pivot question

Postby billo » Thu Oct 26, 2017 9:21 am

Great idea. If the Blutac weight is 180 degrees from the dual pivot and equidistant from the main pivot, an absolute gram force applied at the second pivot is achieved. Otherwise it's a reference value expressed in grams and not the actual gram value applied at the second pivot - and can vary installation to installation.
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Re: not another 2nd pivot question

Postby Letsmakeadeal » Thu Oct 26, 2017 10:35 am

billo wrote:Great idea. If the Blutac weight is 180 degrees from the dual pivot and equidistant from the main pivot, an absolute gram force applied at the second pivot is achieved. Otherwise it's a reference value expressed in grams and not the actual gram value applied at the second pivot - and can vary installation to installation.


Given that the angles and distances are off between the 2nd pivot and the opposing side counterweight relative to the actual pivot point, the value applied to the counterweight to determine the approximate load on the 2nd pivot is exactly that, approximate or better yet a Ball Park kind of number but very much close enough for happy sonic results.

I just load the point with enough force to stay on the plate while in play...My guess is it is probably close to Brent's suggestion of using the same load as the vertical tracking force. It sounds so frickin' good that I really don't care exactly what the load is. That said, Brent's idea on how to get to a measure / value is really thinking outside the box. Pretty dang smart! :D
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Re: not another 2nd pivot question

Postby elader » Thu Oct 26, 2017 11:13 am

Spun a few records last night.

Could having the second point make the table more sensitive to footfalls? Two sites to transmit vibrations to the cart?
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Re: not another 2nd pivot question

Postby Brf » Thu Oct 26, 2017 11:19 am

billo wrote:Great idea. If the Blutac weight is 180 degrees from the dual pivot and equidistant from the main pivot, an absolute gram force applied at the second pivot is achieved. Otherwise it's a reference value expressed in grams and not the actual gram value applied at the second pivot - and can vary installation to installation.


Yup, 100% correct. There are a lot of factors that will affect the result, but none will be significant enough (IMHO) to void the observation. The described method is not an absolute nor a guarantee, but more of a guide based on theory and backed by listening test. YMMV.
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Re: not another 2nd pivot question

Postby Stringreen » Thu Oct 26, 2017 5:15 pm

I got the point.....but as I said above, you don't need this.....as long as the 2nd pivot point is resting on the silver plate, you're in business. Push down on the 2nd pivot at various points in a stationary record to test. If you hear a click, it isn't making contact....increase the pressure on the 2nd pivot until no noise is heard.
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Re: not another 2nd pivot question

Postby Johnny » Sun Oct 29, 2017 8:52 am

I re-adjusted the load on my dual pivot last night and what a difference!!

My original dual pivot load was in excess of 4 grams. Using the counter balance method I re-adjusted it to approx 2 grams and everything just opened up. More high end etc. I am not very good at describing sonic differences, but the change was not subtle. There appeared to be more space around each instrument, if that makes sense.

Playing Miles Davis Seven Steps to Heaven last night was like hearing it for the first time.

I love free tweaks!
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