The snubber schematic is this

crc_snubber.jpg

Values are

Cx: 10nF
Cs: 150nF
Rs: 270R

Caps were red wimas, and R should be 0.5W non inductive.

This is for a primary wired for 230V.

For 110V the Rs should be a bit lower. I am too tired now to look for the wiring diagrams to rewire the transformer for 110V.
If someone can tell me how to rewire it, I will try to get some time tomorrow and get an accurate measurement for 110V too.
In the meantime, something like 250R should be a good starting value to help you evaluate this mod

Unfortunately the motor ICs are not yet here so I cannot test it myself and report any sound changes.
I promise I will report back as soon as I get the turntable up and running.