the perfect platter

[graeme uk]

I want to make a platter, well, a think platter matt to be precise.
Just wondered what the best material for the job would be.

There was talk on here about acrylic being too hard and PVC being the right match to vinyl records, but what about other plastics? What will couple with the record best?

It will be around 10mm thick (or more) and will sit ontop of a glass platter. It will have no other matt on top.
My options are
PTFE
Nylon 66
PVC
Polypropylene
polyethylene
Acetal

I can find all the hardness ratings etc, but i dont know what the ideal is.

thanx folks.

P.S. heres the lists of options

http://www.altecweb.com/home.asp?cat=category3700

scroll to the bottom for other materials.

[sq225917]

get some old records...

a heat gun......

and......

[graeme uk]

Ive thought about it, but making a nice job of it will be hard, and im sure i'd introduce air bubles.

I may yet try it though.

[AuroraB]

Originally posted by sq225917
get some old records...

a heat gun......

and......

What??? How?? just melt it?? PVC??
I have a nice collection of totally worthless, scratched-up LPs that came with the house I bought a couple of years ago......

[Panicos K]

Try a soft material with good damping properties,under the glass platter.A viny mat ontop won't be much better than the LP alone with a clamp.On the other hand,if you damp the glass resonances well,you have a neutral platform for your LP's.

[graeme uk]

I was hoping for 1" thick PVC top platter, but cant find it that thick. Looks like 10mm is the thickest i can get.
Im hoping 10mm will damp the glass better than a thin matt as well as providing a nice solid coupling between the record and the platter.

[honinbou]

BBC engineers used a star mat with their modded garrard 301s. If it's good enough for the BBC, it's good for me...

It's very easy to make. It is just a sheet of aluminum with six buytl rubber pads.

[tvi]

Have you considered a mass loaded vinyl like this 2kg/m² or this 5kg/m² ?

Haven't tried it my self, no TT set-up at the moment, but the sheets are fairly cheap, you might be able to get a cut-off from an installer?

There are quite a few patent out their to learn from.

TURNTABLE SHEET FOR RECORD PLAYER, JP patent 55129905

PURPOSE:To make stiffness large and make periodic damping rapid to improve the S/N ratio, by molding ceramic particles into a turntable sheet for player of a pore rate of 0-20% with rubber or resin as a binder. CONSTITUTION:A rubber binder obtained by adding carbon black to crude rubber, which is made plastic, rubber reinforcement, vulcanization accelerator, etc., such as S powder, CaCO3 powder, MgCO3 powder, MgO and ZnO, and by mixing them uniformly, or a thermosetting binder such as phenol resin, thermoplastic resin such as poly of 15-20pt.wt. and ceramic silicon carbide particles, alumina, etc., of 80-85% are mixed well and are led out into a sheet form and are stamped out into the form of a turntable sheet or are put in a mold frame and are dried and solidified at approximately 180 deg.C after press-molding and are subjected to moisture absorption prevention by surface coating of silicone rubber as required, thus forming the surface of a smooth grain to obtain a turntable sheet. This sheet can be used to reproduce a clear tone quality.

Regards
James

[EC8010]

Originally posted by honinbou
BBC engineers used a star mat with their modded Garrard 301s. If it's good enough for the BBC, it's good for me...

It's very easy to make. It is just a sheet of aluminum with six butyl rubber pads.

I really don't think they were thinking about sound quality, more about getting up to speed quickly. They needed something light and rigid to support the record until the 301 platter rose up and drove it. The rubber pads stopped the record from slipping on the aluminium disc without adding significant mass.