Thanks for all the advice. Here are some responses:
--I definitely agree that I should relegate the Sony to DVD duty and buy myself an audiophile CD player, although I was hoping to avoid that. But, hey, when I have a little more time it should be fun to do the research and the listening tests.
--I like the suggestions to experiment, both with amps and with spectrum analyzers. Currently, I don't know anyone whose equipment I might borrow, so it may take me a while to get around to it.
--In the meantime, I see two votes for Acoustic Zen IC's, and one each for Signal Cable, Cardas 300B, Aural Thrills Active Gold, VH Audio Pulsar, and Mat Ref Mk I. Before I posted I also found recommendations for Kimber Hero. Any other cable suggestions or seconds of these recommendations?
When I buy a new CD player, I'll probably want to get a different, probably more neutral IC. If so, I might try replacing the jumpers on my B60R with this treble-taming, bass-boosting cable.