Hi Jim,
Was wondering what you were referring to so just played the first three preludes on a Richter Lp with a Melodiya label but mastered by Capitol. Then listened to the same by Glenn Gould on Columbia. Very different styles, that aside what you may be hearing is the difference is set up, microphones, and hall. Based just on sound it would be my guess, heavy on the word guess, that Gould's was in a studio and more closely miked, whereas Richter's was in a hall or stage and miked further back. My basis for this, is the decay is more noticeable in Richter's playing, but that could also be just a difference is style or manner. In the Gould it sounds tighter and closer hence a smaller space and/or more closely miked. Hope that helps have not heard any CD versions so can not relate anything concerning them.
Uru975 (aka Michael)