There IS a way for "dirty" ground from a digital environmnet to get over a wire to a "clean" environment, its called a ground loop. In order for this to happen there has to be a loop (hence the name!) A loop is caused when there is more than one path that ground currents can take from one environment to the other, as long as there is only one ground path, there cannot be a loop, hence no contamination.
In order to make this work you have to be very careful about possible "sneak paths" such as through power supplies etc. For example if you have the analog outs connected as well as the S/PDIF out you now have a loop. If you have an external supply that has a three prong plug in which the ground pin is connected to the neg output wire, you can also have a loop. A hard wired ethernet connection might be a possible loop, but as has been mentioned most implementations use transformers and the impedance of these is high enough that most ground noise will not go through them. (just because something is DC isolated does not mean its AC isolated, you have to take the impedances into account) So if you are reasonably careful about isolating the squeezebox from extrnal eleactrical connections, you probably will not be "contaminating" a DAC with digital noise from the SB over the coaxial S/PDIF out. The above is also a primary reason why a lot of people like battery powered digital gear, you have a much lower probability of having a ground loop. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=35031 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
