Hello, Can somone please explain to me what PCM is . . . I mean, I know that it stands for Pulse Code Modulation, but I don't know how PCM figures in my HT system. Is PCM the input source signal used for playing CD's (I use a Toshiba SD2300 DVD player to play CD's). Any links explaining this would be helpful as well Also, I have an ONKYO 898 (which has 192kHz/24bit DACs) w/upsampling capability. Upsampling, as I understand it, doubles the CD's original sampling freq during playback for a more 'detailed' sound reproduction (so the manual says) - what are your impressions of upsampling of std CD recordings (which i think are at 44kHz?) Also, how can upsampling improve on the sound that has already been recorded at a lower sampling freq? Does the DAC algorythms use some type of interpolation to "guess" as to what the recording's signal would be between point in the the new sampling freq? Thanks!