Turntable

flashcider O

... what is vta? ...

There is a good brief overview here.
The definitive work on this was by Risch & Maier, March ’81 Audio magazine here.
This topic - and the related geometry of SRA, HTA (zenith), azimuth, and overhang - confuses many here on A'gon so you'll find a lot of misleading information in the forums.

OK i'm really new at this turntable thing so what is vta? I'm adding 5mm to the acrlic platter so I must adjust the vta and to what?

The Clearaudio CleverClamp is an inexpensive and effective option. 

@flashcider - I place the record directly on the acrylic platter, BUT I also use a Thorens Stabilizer to prevent any slippage, which can occur on some albums, where the pressing is not quite PERFECT.

https://www.ebay.ca/sch/i.html?_nkw=thorens+stabilizer

The benefits of the weight - a much "crisper" dynamic presentation

Regards - Steve

The Achromat is very nice. Let us know your impressions before/ after.  I still think no mat is best with acrylic, but your ears will let you know. Consider a clamp also. 

While I do not believe personally you really need  a mat with the acrylic platter the 5mm Achromat is a great choice, had one and used it for years and yes I ordered from a dealer in England too.
Just remember though you are now adding 5mm to the height your record is sitting at relative to the stylus so you will need to adjust vta to suit

I have decided to get the Achromat 5mm in white. Have to order from across the pond cause retailers here in the states only carry black in 5mm. thanks for the heads up mijostyn, reached out to Arthur Kloubesserian at Funk Firm, very helpful.

flashcider, the goal is to keep the record from resonating and slipping on the platter. A record weight will stop the record from slipping but the problem with a hard platter surface is that it has a much different mechanical impedance than the record thus it will not keep the record from resonating. You want a mat that has a similar mechanical impedance to vinyl then it will serve to dampen any resonance in the vinyl. The Funk Firm Achromat get high marks for this and I would absolutely consider getting one of these. People love them. If my turntable did not come with an excellent mat I would definitely consider getting one!.

Always avoid a mat whenever possible. 

My old Rega Planar 2 with upgraded acrylic platter sounds best to my ears with record direct on the platter, no mat at all but....ymmv.

Enjoy!

If you do decide to try using just the platter sans mat don't forget to adjust your VTA. Personally I'd use the mat which should help minimize micro vibrations. 

I would think that layer of felt would help to reduce rumble and vibration in the table.  What other materials are mats made of?  

free trial with no harm done as mentioned above

decide with your own ears

I've always put the record right on the acrylic platter when the turntable has one.

Try it both ways! You might also consider trying other mats.