Hi Jeff, thanks for a great post. Like you I found sd's comments really interesting. I agree with him that improving your interconnects would give you more music. I went from UHF magazine's recommendations ( Van den Hul The Second, Wireworld Equinox ) to Ensemble Masterflux. Here's what I told the gentleman (an Agon'er) who sold them to me :
(CDP to preamp) Artifacts diminished, female voice became rounder and more three-dimensional. I hadn't noticed before, but the music had been layered and flat-sounding, like a Disney cartoon background. Now it was filling out. The second Masterflux cable (preamp to amp) provided still more of the same kind of improvement : more dimension and naturalness. Harmonies and timbres became more subtle and relaxing, and the music made more sense. Digital artifacts were far less present.
I think you know Pierre Royer. He demoed some of his own handmade cables for me and they made a very nice difference too, at a good price.
Last, if I were changing components in your system, I would look at sources. A good MC cartridge--nothing under a Benz Glider--and a new phono stage would make a big difference. I switched my Copland CTA-301 for a Klyne SK-5A mostly to get the phono, and I love it. But then I'm a source kind of guy. Finally, IMHO your CDP could use an upgrade. Mine is now a Shanling CD-T100 with NOS tubes, and say, if you'd like to come over and spin some wax, you'd be welcome.