Williewonka, well done, very nice read :)
Theoretically, the return/ground should be 0 volts but as your article indicates, it never really is and the resulting noise must colour the signal sound, as you have shown! ... very nice read :)
Theoretically, the return/ground should be 0 volts but as your article indicates, it never really is and the resulting noise must colour the signal sound, as you have shown! ... very nice read :)