Acrylic platter

Dear Lew, I am sorry for the confusion. I thought that the context was 'obvious' but I also know that many thoughts are seldom explicite and contain implicite parts. The acrylic mat (5mm) I was talking about I own for some time but never used because I got, also thanks to you, the SEAC metal mat which is much better than the original Technics
rubber mat. So I was very happy with the SEAC mat and had no reason whatever to search for some other. But because my comrade Don was searching for 'some' acrlylic mat I remebered my own and wanted to check this one first before giving to him whatever advice or present(grin). The 40 euro was my guess about the price.
So to check this acrylic mat I removed the SEAC mat from my Sp10 and was surprised with the sound of the acrylic in comparison with the SEAC metal mat. But thinking about possible explanation I remebered the Lurne's philosophy about the platters and of course the circumstance that I owned one of his TT's the Audiomeca J1 which had no mat at all. His explantion was that acrylic and vinyl have similar 'structure'. This make more sense to me then 'metal on metal' approach. But this is of course my own subjective opinion without any 'objective claim'.
I own the Kuzma Stabi Reference at present which also use acrylic but like Lurne's Audiomeca as a sandwich with aluminum plate in between instead of lead like Lurne, probaly because lead is not allowed at present. So I am not sure if your objection would apply to such use of acrylic also? I have some idea how metal platters are 'balanced' but have no idea how the acrylic platters are made. I also have no preference one way or the other for the simple reason that I am an simple amateur. Anyway I would also like to try those Boston Audio mats that you also mentioned in your advice to me. But back then I was able to get the SEAC mat for an very attractive price.

Nandric.
My two cents worth on this subject.
I run a heavily modified SP10 MK3 and have replaced the platter completely with an acrylic one with lead sheet insert and duralium magnet motor housing, to bring the weight back up to 10 kg. I personally found this to be an improvement over the stock platter.
I think that criticism of acrylic as a platter and plinth material is valid in most cases but it needs to be taken in context. For example, I do not like the "sound" of acrylic on its own as a platter or plinth. What is important is the implementation and in particular what the acrylic is bonded to and how this bond is achieved. Done right, IMO, it is possible to get the best of both materials without the negatives of either.

I think acrylic in combination with other materials might work fine. It is only those solid blocks of pure acrylic platters to which I object. I hold the Kuzma Reference in high esteem. I did not know that it uses a composite acrylic platter. In photos, the surface seems to be something solid and black in color, i.e., not acrylic.

Richard, Did you take the circular magnet structure off of your stock Mk3 platter and remount it on your home-made one? You are indeed fearless and adventuresome, if so.

Lewm.

No I am not that brave/reckless. I have the original platter complete. I took measurements from this and machined up a new magnetic housing.

Re acrylic, I think that the trick is to get to the higher transmission speed material thru a minimum amount of acrylic. You could say that I am using a duralium platter with a bonded acrylic mat. The acrylic part of the platter is only 6mm thick.

thanks

Lewm.

I may have misunderstood your question....
Yes, I changed the motor magnet and speed sensor cup over from the original platter into a newly machined dural housing.