In his Listening column, Art Dudley mentioned that he removed a troubling hum by "floating the signal." I have searched for this term but haven't found it anywhere. I tend to suffer from the sort of hum he describes because of the sensitivity of my speakers (an Altec Lansing 210 Voice of the Theater, split into a stereo pair of highly customized cabinets for home use and WAF, and one Altec mid-/high-frequency lenses with compression driver for each channel) -- about 108db/1m/2v based on conventional wisdom. Can anyone tell me how to "float a signal" so I can try it with some of my more troublesome (hum-wise) components? Thanks in advance for any help.