Level on tonearm

Level on tonearm

Postby mflaten » Tue Mar 06, 2018 2:43 pm

I think it would be a very nice feature to have an embedded level in the tonearm. The adjustable tonearm is not used to adjust the SRA but to adjust for different thicknesses of records and having a small level would be a good feature.

Harry and Mat, would do you think?
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Re: Level on tonearm

Postby Brf » Tue Mar 06, 2018 3:36 pm

There are two issues that I can think of. A micro bubble level is too course to discern the difference between a standard 150g and a heavy weight 200g vinyl album. Moving mass within a tonearm (fluid) is typically not a good idea.

If you are concerned with maintaining the exact same SRA with a 150g vs a 200g, you can easily calculate the difference and raise the back of the tonearm by adjusting the VTA tower accordingly. Please see the following link for addition details http://vpiforum.com/viewtopic.php?f=12&t=9207&p=35207&hilit=sra#p35207
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Re: Level on tonearm

Postby mflaten » Wed Mar 07, 2018 5:58 pm

Yes, I have already calculated the amount needed to increase or decrease for different thickness of records.

I'm thinking a small narrow level could be just forward of the pivot where the collar is slightly larger than the rest of the tonearm. At that point the fluid in the level will have virtually no effect. Also after doing various adjustment it would be easy to get back to level.

Second, is there any plans to incorporate the second pivot into the tonearm? Here I could easily imagine where the second pivot could be optional. If you wanted the second pivot just insert the screw, if not, retract it and use the unipivot. I also think it would be better to incorporate the 2nd pivot slide plate to be permanent and just stuck on the base. I am hoping that Harry and Mat incorporate the 2nd pivot into the arm.
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Re: Level on tonearm

Postby jonathanb » Wed Mar 07, 2018 6:01 pm

Regarding the 2nd pivot point, I doubt that VPI ever incorporates it into the arm because of the substantial number of arms that could/would be damaged by the process of drilling a hole for the pivot screw. (I believe this is the reason they ultimately chose the c-clamp approach for the 2nd pivot mod.)
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Re: Level on tonearm

Postby mflaten » Wed Mar 07, 2018 6:11 pm

I am not suggesting retrofitting but incorporate in the manufacturing of arms going forward.
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Re: Level on tonearm

Postby Brf » Wed Mar 07, 2018 7:08 pm

Building a level into the tonearm wand would affect the effective mass, the distribution of mass along the longitudinal axis, reduce rigidity, alter the wands resonance frequency, impede the internal tonearm wires, affect shielding, plus a host of others issues. Imho, these are not acceptable performance compromises for the sake of convenience.

With respect to incorporating the second pivot into the 3D printed azimuth ring on future production runs - I’m with you on this one. This is what VPI did in the initial prototype stage. The only rationale that I can think of for using an outboard second pivot is to extend the second pivot farther away from the main pivot to reduce the rotational torque required to move the pivot.
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Re: Level on tonearm

Postby mflaten » Thu Mar 08, 2018 9:51 am

Outside of the level on the tonearm, how about a small plastic device (~ 8' long) that could sit on top of the record to be played and under the arm to sight in level. Even if it was 1/8" below it would be easy to sight in.
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Re: Level on tonearm

Postby Brf » Thu Mar 08, 2018 11:32 am

mflaten wrote:Outside of the level on the tonearm, how about a small plastic device (~ 8' long) that could sit on top of the record to be played and under the arm to sight in level. Even if it was 1/8" below it would be easy to sight in.


You can purchase micro bullseye bubble levels that sit on top the headshell which will allow you sight in level. Although very light, they will affect the VTF that the cantilever sees, therefore the cartridge will ride a touch lower than when played.

As an alternative, a lot of users have spoken highly of the Millennium - Acrylic VTA Block - https://www.musicdirect.com/analog-accessories/millennium-acrylic-vta-block
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Re: Level on tonearm

Postby Harry » Fri Mar 09, 2018 11:59 am

I personally like the second pivot incorporated in the azimuth ring but it is a nightmare in production as a few arms were damaged putting in that hole and then threading it. Mat and I came up with the add on piece that eliminated the damages and made the pivot further out for greater stability.

Funny you mention the bubble level, a customer came by this week with a micro level and says he uses it all the time. I find it very hard to use levels that are not machined as they are not accurate enough. I use a 4" round machined bubble level for leveling the table, it is very accurate. A thought would be one that was about 1" long with "V's" put in the bottom on both ends and place that on the tonearm itself near the pivot. Just a thought!

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Re: Level on tonearm

Postby Golear » Fri Mar 09, 2018 1:30 pm

I'm playing around with the following method. I like this approach because the VTA adjustment can be made when the stylus is not on the LP.

Raise or lower the arm until the top of the arm is parallel (using a home-made ruler device, or the acrylic device Brf mentioned).

Get a Stanley laser level (https://www.homedepot.com/p/Stanley-Man ... /205764000). They're available at Lowe's, too.

Place the laser level on the LP, on its side so that the laser makes a horizontal line. The little plastic protrusion on the side of the body has to be shaved off with a hobby knife.

Make the laser shine on a part of the arm that goes up and down as the VTA is changed. With my cartridge, the laser catches the arm rest hook when it is rotated to the max "up" position. That's your reference point. Mark the line position on the hook (or take a photo of the laser shining on the hook).
(If the laser does not shine onto any part of the arm that goes up and down, one could attach some kind of a ruler or scale to the arm.)

When you change LP, put the laser on the new LP. Since it is a different thickness, the laser will light up a different part of the hook. Move the VTA up or down until it hits the reference point, like before. Refer to the photo, if needed.

That's it. You've moved the VTA up/down, to account for the LP's thickness. Make final adjustments by ear for each LP, to account for different groove depths, and angle at which the LP may have been cut.

(The laser beam will be quite thick. You can reduce the width by making it pass through a narrow gap. I put two strips of electrical tape on the front slit, leaving a gap of about 1 mm. I'd love to find a laser that produces a really, really narrow beam, or focused a spot.)

Memo to self:
1. Make some optical thingy that will amplify height differences. May be a prism...?
2. Make the laser shine onto some sort of light detector, and have some "brains" that will move my VTA adjuster automatically.
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