Turntable lid up or off?

The ultimate test is just listening, but I cannot detect a difference between either mode (up or completely off).

There you go.

G

I have always taken the cover off.  The rationale is to avoid vibration when closing it or worse case scenario the cover slamming down.

My forced air hvac system creates a LOT of dust, I could never leave a dust cover off when not in use.

UP, to avoid ’trapping’ and ’reflecting’ micro vibrations.

OFF, if possible, for appearance, at least for long listening sessions, I guess I would simply leave the hinged type up for single play, like I used to do with an Audio Technica I had.

In my case, the cover on the big JVC plinth is large, heavy, unattached, it must be removed. Luckily it has notches on the sides to get a good grip on it. And bimps on the plinth to align the front first, then lower without hitting anything. Very important in my situation, I have very small clearances: height and sides of 2 of my 3 arms I squeezed in there.

Notches are an advantage: not needing to reposition your hands. Off, down, lean vertically to defy gravity, back up to TT, no need to walk anywhere.

I put felt pads on the edge resting on the floor, to keep from scuffing it to hell and back, resist sliding, and isolation from floor vibrations.

When I got my SL1200G turntable, I listened both ways, with the cover open or closed using the same record.  After about 10 try’s, I found the open position better and go with that now. 

Seems a lot of higher end decks don’t come with covers so my guess is it doesn’t make a difference or better to be off. Great to keep dust off is probably all it does.