[Otis]

I'm dealing with one ringy platter here, folks.  It's really bad.

For reasons too dull and technical to go into, I can't change the inadequate topside platter mat, but I can afix some kind of damping to the bottom of the platter.

The question is, should it be spray on undercoating type stuff, or good old plasti-clay? Is there a better third way?

What do you say?

[TheChairGuy]

Otis,

Platter balance is of great importance...all the more likely with belt drives (you don't mention what type you have...but it doesn't matter too much re: your question)

Further, clearance of platter bottom and top plinth is often scarce.

Spray on damping is relatively thin, light and inexpensive.  You are far less likely to throw off platter balance using it over plast-i-clay.

As one experienced in using both substances (and a few illegal ones, too )

John

[strider]

Otis,

I sprayed the bottom of the metal platter on my Debut with automotive undercoating out of a spray can. Bought the most expensive they had at the parts store. Definitely worth the $7 for the can, helped tighten up the bass and provided a bit more definition all the way 'round. I did light coats, turning the platter about 90 degrees for each coat to help get even coverage.

Ben

[orthobiz]

I say that some things sound so logical and easy that it's a wonder the companies don't just do it from the outset!

Paul

[TheChairGuy]

I say that some things sound so logical and easy that it's a wonder the companies don't just do it from the outset!

Paul

The Technics SL-1200 has a bitumen damping wad on the underside of the platter already.  It does a nice job of dumbing down the ringing on the otherwise thin aluminum platter.

For the rest of the makers out there...'logic' (ie, good sense) is often lacking, to be sure.

John

[Berndt]

I've cut rings of dynamat with a gasket cutter for the empire platter.
3~4 layers and you have 5/16" of dead material...

[lcrim]

Adding any material to the bottom of any TT platter is not recommended.  The chances of causing problems w/ clearances or balance is too great a risk.
Both my present TT platters have an Isoplatmat from SDS to eliminate any chance of ringing.  Its a very thin double aluminum plate w/ a layer of damping between.  It works.
Review and more info- http://www.enjoythemusic.com/Magazine/equipment/0706/sds_isoplatmat.htm

Just checked there's a guy selling one on Audiogon.  BTW- I am not related in any way to the manufacturer or the seller.

[Wayner]

Just cause the platter rings in your hands doesn't mean it rings when in service. I like Larry (Icrim)'s advice about putting shit on a turntable platter. My Empire and ARMod (AR) turntables all have aluminum platters and sub-platters. With the mat in place, the ring is really not there.

Many manufacturer's go thru the hassle of balancing the platter to reduce rumble and most do a good job at it. I'd be hard pressed to spray anything on the inside for fear of un-even coating. Certainly do not put plasticlay on. That will surely put things out of balance.

Wayner

[Scottdazzle]

Try a Herbie's paltter mat.  Some are haevy and thick and would probably damp the ringing, as well as help isolate the record from the platter.