[sdiy] To float or not to float?

[anthony]

I've noticed in some tube amp designs, the speaker output is left floating 
while other times one end is grounded. I understand needing to ground one 
side when you are implementing some negative feedback from the speaker out 
put. ut why ground it when there's no feedback? Does it reduce hum? I would 
think not - especially if it was just grounded at the jack right as it 
touches the chassis rather than a common ground further inside the chassis.

So: to float or not to float?

cheers,
Anthony