Harp
Especially in the lower range
Vibraphone
Same
Theramin
Absolutely gorgeous in its own wobbley way. There is something profoundly soothing about this thing that I cant really explain but its otherworldy, almost utopic and chronotopic
Glass Marimba
Soft mallets
Bass Marimba
Extrapolating here but I cant see how it wouldn’t
Firstly, this assumes that “timbre” is a fancy word for “sound characteristics”. I would definitely have troubled defining it.
Piano.
For me no contest.