Very odd to me. To use an example many people are familiar with, the guitar solo at 4:00 in Pink Floyd's, Money, does not happen. It is as if the guitar was not recorded. The other guitar solos are there loud and clear. That particular one is a different sound from the others, and it is silent. Same SACD in another stereo and it's there. Lp has same results except it is faintly in the background. I first noticed this with a Harry James LP. The trumpet sounded as if it was in a closet with the door shut. Everything else in the system sounds fine. I happen to have listened to the Harry James only a few weeks ago and it was excellent (Sheffield Labs Direct to Disc). When I listen through the headphone jack on the preamp the solo is there. I have switched out components and eliminated everything except the amp. I'm using a Mac 402 with Mac C45 preamp. All other components are high quality. Anyone have any ideas?