As I proceed through my CD collection with my new BHK amp/pre combo, I believe I have a better awareness of the nature of their contribution to my greater musical enjoyment. It is the reproduction of greater low-level detail. Indeed, on some recordings that happen to have an abundance of such detail, the improvement is almost startling. As in “my god I never thought this recording could sound this good.” It may be responsible for the more 3-dimensional soundstage which I really appreciate in classical recordings. In general, the better the recording, the greater the perceived improvement over my old preamp/amp.
Prior to my inclusion of the BHK amp/pre combo, I thought I was listening to best sound possible from my CDs and the limitation was the CD. I now believe there was some limitation in my equipment and my CDs may have more to give.