I recently bought a used Technics SL-1200 MK2. Unfortunately, it makes a slight(!) buzzing noise when I connect the needle cartridge to the tone arm. The cartridge is not the problem as it works fine on my SL-1210. Also, it's not a loud or harsh buzzing noise like the one you get when you don't ground the turntable properly. Only an audible, but quite annoying one.

Does somebody know what could cause this? Thanks for your replies!

- Christopher