Dust cover on or down when NOT playing, up or off during playback. This is what I was taught by the "old-timers" when I was young. The dustcover can exaggerate or amplify microphonics. Turn your system on. select the phono input (do not actually play the record). Leave the tonearm cued in the "up" position. put the dustcover on or down. Gently tap on the dustcover and plinth. Repeat the tapping with the dustcover "up" or off. With most tables and cartridges you should hear a significant difference.
Ok guys
My question is this, nothing major, more of a curiosity. When playing an album does it make a difference if you leave the dust cover up or down? Probably stupid question but hey there are lots of opinions out there