There is actually some rational information on this subject as well. See:
http://www.dself.dsl.pipex.com/ampins/groundloops/grndloop.htm Figure 3. For equipment with an ungrounded chassis, one can measure the AC voltage from the chassis to safety ground. When I first thought about this, my impression was that reversing the mains plug would only reverse the polarity of the AC error signal and not affect its magnitude. But apparently this relationship does not always hold with real hardware. The only reason I can think of for this is some kind of asymmetrical load between positive and negative supplies of typical hardware, giving a partial cancellation of the residual AC signal in the "preferred" state. Because the residual signal is from an asymettry of the transformer, the "optimum" polarity will vary from unit to unit. Of course, audibility of this situation is debatable - yet I'm sure it will be trotted out by the usual suspects for some time to come. -- andy_c ------------------------------------------------------------------------ andy_c's Profile: http://forums.slimdevices.com/member.php?userid=3128 View this thread: http://forums.slimdevices.com/showthread.php?t=36626 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
