Cabe;345612 Wrote: > Did you really mean to only connect the RCA to the hot and cold of the > XLR Plug? Yes. Cabe;345612 Wrote: > Given that the sleeve on an RCA is 0ve rather than an inverted (180 > degrees out of phase) signal . The signal seen by an amplifier is the difference between two voltages. In an unbalanced amplifier, it's the difference between signal and ground. In a balanced amp it's the difference between hot and cold. The ground connection on a balanced amp is separate from the signal.
Hence the two voltages defining the signal at the RCA end (pin and ring) should be connected to the appropriate places at the XLR end (pins 2 and 3). By not connecting the grounds of the unbalanced source and the balanced amp, you avoid the possibility of a ground loop. On the other hand, if the unbalanced feed has a floating ground (eg. a Squeezebox), then any ripple on its nominally 0V line will not be shunted to earth and will be interpreted as signal by the balanced amp. That is why you would then join the grounds with the aim of shunting the ripple to earth via the balanced amp's ground. (And since the Squeezebox has no earth, you don't introduce a ground loop). But as explained in the wiki, not all balanced amps have pin 1 directly connected to earth. In such cases you have to find another way of shunting the ripple to earth. -- cliveb Transporter -> ATC SCM100A ------------------------------------------------------------------------ cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=53262 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
