On Mon, 20 Mar 2006 00:51:28 -0000, Roderick Stewart
wrote:

Did you measure anything objectively with instruments? Anything at all?
Doesn't it ever cross your mind how remarkable it is that after the mains
current has travelled all those miles underground and overhead, the last
few feet can make such a difference? Are you sure you're really hearing
what you think you're hearing?

He's suggesting that a filtered power lead can reduce interference
from an adjacent computer. Not that it's improving the mains supply
as such.