[simoon]

I recently got a Teac TN-400 from a friend that no longer listens to vinyl.

It has a 6.8 pound aluminum platter that I can't help but think could be improved by damping.

What does anyone think?

[Ericus Rex]

The rubber mat dampens it to some degree.

[SET Man]

Hey!

   Nice table there.... lucky you.

   Anyway, to damp it and keep it perfectly balance can be tricky depending on your damping scheme. And at 6.8lbs is pretty good and definitely not one of those cheapy table with stamped platter.

   Like Ericus said, the rubber mat is already damping it. If it sound good to you now than enjoy it!

Take care,
Buddy

Edited: Oop! I meant "not one of those" forgot to put "not" 

[SteveRB]

Some people have used a spray adhesive on the platter to adhere the matt to get a little more performance and dampening...

cheap tweak, might be snake oil.

[simoon]

Thanks for the replies so far.

The platter still rings a bit with the mat in place.

I was considering precut sorbothane pads like these - http://www.tweakshop.com/BlackHolePods.html

The underside of the platter has a bunch of sections where they could be placed that would insure that they were equally spaced. So I believe it can be done without effecting the balance.




I guess experimentation is the best way to go.

[Wayner]

That would be incorrect. You could not possibly cut any pieces of deadening material, place them in strategic locations and not affect the balance of the platter. You simply can't be that accurate. The end result is that your table's drive is going to constantly correct it's speed every few milliseconds and that will F up the whole rhythm/pace/bla, bla, bla scenario ......

Wayner

[simoon]

That would be incorrect. You could not possibly cut any pieces of deadening material, place them in strategic locations and not affect the balance of the platter. You simply can't be that accurate. The end result is that your table's drive is going to constantly correct it's speed every few milliseconds and that will F up the whole rhythm/pace/bla, bla, bla scenario ......

Wayner

That's why I was going to use pre-cut or molded pieces. Also, the underside of the platter is very easy to measure in order to get them in the exact same location.

But I'm thinking of going about it in differently anyway. I'll report if I think it makes any difference.

[poseidonsvoice]

That would be incorrect. You could not possibly cut any pieces of deadening material, place them in strategic locations and not affect the balance of the platter. You simply can't be that accurate. The end result is that your table's drive is going to constantly correct it's speed every few milliseconds and that will F up the whole rhythm/pace/bla, bla, bla scenario ......

Wayner

Wayner,

Great point. What is your view on how periphery rings and center weights affect the platter? I figure since a number of manufacturers sell this, notably VPI, that it should not effect the balance of the platter since it's equal on all sides, yes?

Thank you,

Anand.

[jtwrace]

Wayner,

Great point. What is your view on how periphery rings and center weights affect the platter? I figure since a number of manufacturers sell this, notably VPI, that it should not effect the balance of the platter since it's equal on all sides, yes?

Thank you,

Anand.

As long as it's properly machined it cannot and will not affect the balance.

[Wayner]

As long as it's properly machined it cannot and will not affect the balance.

Agreed. Although it will put more pressure on your thrust washer (which may or may not be bad, if your machine is built like a BSH.

 

[jtwrace]

if your machine is built like a BSH.

 

[jtwrace]

This is probably worth mentioning.  The spec that some turntable manufacturers give that the platter is within +/- .001" is for this exact reason.  That is the tolerance of the outside dimension of the platter.  Very very easy to hold a tight tolerance but like anything it's down to the operator.  Whether it's a rim or belt drive this will have an effect on speed and balance.

[Wayner]

However, many older platters were cast and casting uniformity can be a problem. That means that while the outside may be within close tolerances, the consistency of the casting may very (internal bubbles, etc.) that will throw the weight out of balance. Just as even new tires and rims need to be balanced on your car, so do platters.

Empire was one older company that claimed exceptional platter balance, especially in the early days with models such as the 208/298. They had secrets how to do it consistently correct.

It's probably not a problem with most new acrylic platters.....

Wayner

[jtwrace]

However, many older platters were cast and casting uniformity can be a problem. That means that while the outside may be within close tolerances, the consistency of the casting may very (internal bubbles, etc.) that will throw the weight out of balance. Just as even new tires and rims need to be balanced on your car, so do platters.

Empire was one older company that claimed exceptional platter balance, especially in the early days with models such as the 208/298. They had secrets how to do it consistently correct.

It's probably not a problem with most new acrylic platters.....

Wayner

Absolutely.  On those if one wants perfection, I'd recommend drilling on the inside "meat" to balance the plater.  Drill or mill works fine.