Dustcover material plays a big part in transmitting the noise as well. I have an acrylic dust cover that I made for my clearaudio tt. It came originally from a pioneer pl41. It's a separate unit from the tt and it makes no difference whether it's up or down or completely removed. I also have a hard plastic cover on my thorens that rings like a bitch so it sounds better if it's removed completely. Up or down it still rings so I remove it when I'm using the thorens. I'd have to agree that there isn't one size fits all. Whatever set-up that seems to work best for you is the one I'd recommend that you use.