Technics platter mat design and azimuth setup

[Stratmangler]

A dished recess in the mat shouldn't cause any playback issues, as most vinyl will self support.
It will minimise the record to platter contact, which may or may not be a good or bad thing, depending on your point of view.

Many records are not flat by design

[Fergus]

Hi there and thanks for your interesting reply.

I think the last message from Stratmangler (haha nice moniker! Maybe I should be Telemangler) probably explains it.
I think the less contact there is, the more isolation form the platter there is.
So this would explain why some mats are dished or have those raised 'bits' that get slimmer towards the middle.

But I'm not very sure if that's the reason. Does anyone know for sure? I kinda doubt that they're designed so that warped records can be played with weights.

Fergus

Hi
Fergus, now that’s interesting. I see that the Sony designers also focused strongly on mat design. The ps4750 had a moon mat, did those circles have some suction effect? This would be a design consideration to prevent record movement, very different solution to a clamp/weight solution. Then I see the top Sony mat was the oil filled one, and Sony actually say to reduce vibration! No dishing effect on Sony mats!?

So I’m seeing 2 requirements- 1. Prevent vinyl slippage and 2. Reduce vibration.

Anymore requirements a mat should meet?

Maybe a space undeneath as you have observed Fergus, but why?

[karma67]

...also Oyaide must have researched the best azimuth angle for their mats other than 90 degrees. I guess we are truly into the ‘art’ of vinyl replay here. I can alter azimuth with one of my head shells to experiment.

There is no better azimuth than 90 degrees

[Teleton]

Thank you Jamie, this is my thought too.

I see that Jvc, and Yamaha designed an electronic mat air suction device on their top decks. Wow such elaborate design, Sony too?