turntable and platform isolation

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rif

turntable and platform isolation
« on: 29 Mar 2011, 03:16 am »
I'm new to isolation products, little overwhelmed by your choices so thought I'd post.

I have a VPI HW19 turntable on a target shelf on an exterior wall. It's a heavy turntable, maybe 60 pounds and uses a spring suspension.  the target shelf is a fixed metal perimeter that contains a levelable wood shelf in the middle. The table is also pretty large, it's a little too big for the shelf. I had to put a wood board w/friction tape btwn the target shelf and the turntable. Phew

I set this up only a few days ago and don't seem to have any footfall issues.

1) Do I want to use isolation between the target shelf and wood board or between the board and the turntable?
2) Am I paranoid to worry that isoballs under the turntable could cause it to 'roll' off the shelf?
4) I think VPI now recommends the springs be replaced with a product they sell (sorbothane?). I know it's a long shot, but do you have something comparable?

--david


Herbie

Re: turntable and platform isolation
« Reply #1 on: 29 Mar 2011, 01:56 pm »
Hi, David.  For optimal results, you'll want to isolate both between the shelf/board and between board/turrntable. Use four or more 1" grungebuster Dots or Extra-Thick grungebuster Dots between the shelf and board. Since you don't have severe footfall problems, four regular Tenderfeet between wood shelf and turntable would be ideal.

We have lots of VPI owners using Big Tall Tenderfeet in place of both the original VPI suspension springs and Sorbothane "upgrade" springs, enjoying superior results with the Big Tall Tenderfeet.

(BTW, IsoBalls do not roll; they are held firmly by their stainless steel bases; components will neither roll nor slide on the balls.)

Steve
Herbie's Audio Lab

rif

Re: turntable and platform isolation
« Reply #2 on: 30 Mar 2011, 05:18 pm »
Hi Steve. Thanks for the quick and detailed reply.  Unfortunately I am rethinking my current shelf setup. I,m most likely getting rid of the Target and making my own shelf. I'll keep your products in mind when designing it.

--david

rif

Re: turntable and platform isolation
« Reply #3 on: 4 May 2011, 11:17 pm »
Hi Steve

I'm finally ready place an order. I can't believe it's taken me this long to revamp the design, hire a woodworker, etc.

My biggest questions are on precision -- the grungebuster dots and washers come in metric as well. Do I really need that kind of precision?

I'll have 2 wood platforms, separated by metal isolation cones (one platform attached to the wall, the turntable on top of the other).  I'm going to place 1/8" dots under the cups the cones rest in. On top of the cone, I was thinking of 1/16" washers -- top of the cone is attached to wood with threaded stud. I had the woodworker recess both places to make it look clean.

So do I want to order dots that match the recess diameter (7/8" - need 1 thick dot) or the cup diameter (18mm -- need 2 thin dots)? Or split the difference at 3/4"?  Am I being too much of a perfectionist???

thanks for your help
--david

BTW --did you change your site? It's asking to allow new java and cookies. no big deal, just unexpected.
 

Herbie

Re: turntable and platform isolation
« Reply #4 on: 5 May 2011, 01:41 am »
Hi, David. Some people are more familiar with metric sizes, some not.  Grungebuster Dots and washers have a jillion potential uses; in most cases, exact precision isn't needed and your best guess regarding size is appropriate.

Grungebuster Dots placed against the flat side of cones or under cone cups usually work very well at the same size, or just slightly undersize in diameter for neat appearance. Either 18mm or slightly larger 3/4" will do fine; I think appearance would be the only significant factor between them. The Dots would not have to precisely fill the entire recess, but there would be no harm in that, either.

Though not every size is listed, Extra-Thick grungebuster Dots can be made in any of the sizes listed for Thin and regular grungebuster Dots, so you wouldn't necessarily need to stack two thinner Dots to achieve a desired thickness. By stacking, however, you have additional leverage with auditioning--you're likely to find that a single thinner Dot is sufficient or ideal and end up with some extra Dots for use elsewhere in your system.

When using grungebuster washers in a configuration where a nut or spike end will be tightened against the washer, you'll want a matching Teflon washer so the nut can be turned against the material and tightened without pinching the grungebuster material.

(We're continually making changes to our website. The website shouldn't be asking for a cookie unless you're going to place an order on the Shopping Cart or post to one of the comment boards. Nowadays you pretty much need Java enabled to navigate and use the web.)

Steve
Herbie's Audio Lab