Vintage DD turntables. Are we living dangerously?

Halcro,it is a great question -I also wonder about this. I used a heavy 5Kg Audiolife platter on my SP-10 for 6 months and guess what, it started to go wobbly and not hold a constant speed - it is now at my tech being repaired. I suspect the bearing will survive, but I am also interested to hear from others on the motor concern. I have used my SAEC mat on my 101 for well over a year with no issues, although like you observed the stop is not quite as crisp as with the stock rubber mat. BTW,the SAEC mat is superior to the CU-180 on my 101 and Lenco, whereas the CU-180 is better on my Micro SX8000 and L0-7D.

Halcro, Radicalsteve, in place of these heavy platter mats, why not consider trying a delrin mat. I believe Applied Fidelity has it for sale. If not satisfied with the sonics of the mat, send me a pm then I will discuss a diy one that you will be happy with.

What is the theory of a heavy copper mat? I can see adding to the flywheel effect, but that isn't how most dd turntables including the 101 work. I can see it as a EMI shield, but the TI material is probably better as it was designed for that purpose and it weighs relatively little. There has tone better mats for draining record vibrations (I like the achromat) and sorbothane is probably better at damping a ringing platter. So, what is it?

I don't know what it is Aigenga.......but the Cu180 improves both frequency extremes in a consistently audible manner :^)

There are possibly several things going on with a copper mat. My Final Audio has a 4.5kg copper mat - the copper mat in conjunction with the 15kg aluminium platter provides bi-metallic damping, tapping the platter with and without the mat demonstrates the effectiveness, and is also a calculated energy path for the stylus/record by the designer to provide a mechanical ground. All other mats I have tried are significantly inferior on this particular tt.