My turntable comes / came with a minus K platform from the manufacturer. I’ve never heard what you are describing. Perhaps you need to turn up the strength of the minus K force so that the turntable is not resting on the platform, but floating above it.
Minusk platform
The topic concerns mostly those who use a minusk turntable platform.
I am using a minusk under my turntable. The only issue i have is when i give an impact directly on the minusk (using my finger for example) OR on the platform on which the minusk stands, there is a metallic sound - ringing heard. This sound is also heard from the speakers (i use mc cartridge). Obviously the minusk being metal it will cause higher frequency ringing. This will be over 100 Hz where minusk runs out of isolation.
what way have you solved this issue or did not have to?
thanks