The MinusK should isolate you from everything over 2 hz. You are shorting somewhere. What turntable are you using? Check to make sure the platform is floating correctly. You should be able to tap all around the MinusK and not hear anything through the system. If you tap the top of the MinusK, the surface your turntable sits on you will hear it to one degree or another depending on the construction of your turntable. This is normal.
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