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Very cheap rega p2/p3 tweak

I can't remember where I originally read this tweak, but it took me a couple of months to get around to trying it (hey I've got a 3 yr old at home ... it takes weeks to do anything !)

I have an old rega planar 3 with the upgraded motor (which is stuck directly to the plinth, as opposed to the older regas that use a motor suspended on the rubber bands ... I don't know how well it would work for them).

First you need to remove the platter and the belt.

The idea is to minimize the transfer of noise from the motor to the platter and the arm. To do this get a small patch of self adhesive damping material (sold in auto stores for damping body panels) and cut a piece to surround the motor pulley, without catching on the subplatter.

I cut a small oval, approx 2 inches by 1 inch with a hole in the middle big enough to go over the motor pulley. Stick this down on the plinth making sure that the motor pullay and subplatter don't catch on the material.

Next I cut a ring (or more correctly an annulus) of the material to go around the subplatter, to intercept any surface vibrations between the subplatter and the arm. Since I did not test in between stages I can't say whether this gives much additional benefit, but the material is cheap and it only takes about 5 minutes extra. My guess is that sourrounding the motor pulley is the more important step.

Once all of the material is stuck down replace the platter. This conveniently hides your handy-work, if, like me, it isn't looking too neat.

Since I was in a rush I can't claim to have done a careful before vs after analysis, but I have now lived with the changes for about two weeks and I think that there is a very noticeable difference in the quietness in between tracks. This translates into a crisper, more dynamic sound during the music, since the signal to noise ratio is improved.

Overall for about $10 of materials I'd say I'm very happy with the improvement in the sound. I have not gone further and coated the entire underside of the plinth with this material ... my guess is that it would offer some improvement, but with diminishing returns since the motor is the chief source of noise in the platter, and due to the way the motor sticks to the laminate layer, rather than to the mdf. It looks a bit messy with the platter removed, and the damping material is very sticky and almost impossible to remove, so don't try this if you ever intend to trade the deck.

If anyone tries it then I'd appreciate a follow-up post to relate your experience. Happy cheap tweaking.
seandtaylor99
seandtaylor99 OP
1,262 posts
 
"The motor being stuck to the bottom of the table does seem to be the weakest link. But dampening around it seems less effective than finding a way to separate the motor from the plinth"

Agreed ... but separating the motor is a lot more work. Perhaps when my kid has left home :-)

And I'm sure Roy didn't specifically engineer the Regas to transmit a lot of motor vibrations to the arm. It's a trade-off of the low cost. If you look at the cost of a P3 versus an RB300 there's not much money left to build a good plinth, so my guess is that is where the money is saved, and a good place to improve.

Acrylic platters need to be weighted with something (steel, lead) to be the same mass as the glass platter for rotational stability. A correctly weighted and balanced acrylic platter will be over $100 ... too much money to be classed as a tweak on a deck that cost me $300 many years ago.

Thanks for the response.
creativepart's avatar
creativepart
154 posts
 
Why not dampen the plinth inside the motor recess from the underside rather than on top where it is visible?

Paul Green
PS. I was talking about making an acrylic plinth not an acrylic platter.
seandtaylor99 OP
1,262 posts
 
Sorry for not reading carefully enough .... and for having "acryllic platter" on the brain. It's a hot topic at present, though I'm not convinced it's worth the money.

I have read of at least one person who has housed the motor in a separate assemly and then found an appropriate length rubber band to drive the platter. I can imagine this would work well. Perhaps if you'd baby sit for a week or so ....

I agree that damping inside the motor housing is interesting .... however I'd watch out for heat dissipation in there.

If you ever feel so inclined perhaps give "my" tweak a try ... I was really surprised by the magnitude of the improvement from a 5 minute exercise.
creativepart's avatar
creativepart
154 posts
 
I will say, when I upgraded my motor from the rubber band suspended motor to the glued on motor I noticed that the material left to support the motor after the motor recess had been routed out at the factory was mightly thin. You might find that something more substantial in this area -- a thin wood or metal plate that is glued to the top of the plinth that ties the thicker parts of the plinth to this thin layer of laminant might be even more beneficial.

There I go trying to make the Rega plinth stiff again.
Paul Green
pcv2016
1 posts
 
I figure if the motor is the source of noise, why not create a buffer between the sub platter and platter. I found these rubber sheets at Michaels that are only a millimeter or so thick. I simply cut a piece to cover the sub platters contact with the platter. This raises the platter relative to the tonearm, but very slightly only (probably similar to a thick record matt). The background is definitely quieter. 
Any comments? 
I am curious if anyone else has tried this
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