I was going to suggest California Audio labs as well. It will give him a taste of high-end sound and not break the bank(consistant with what he already owns). It's a shame they're not still in the audio business. See that he invests in some decent interconnects while he's at it too(ala Kimber), if he hasn't already.
Is there a truly musical multiple CD player?
And if so, what is it? I've got a friend who has a reasonably good system, Gallo Reference 3.1s with the bass amp, and an NAD T-785 receiver. I keep telling him that if he wants real music he will have to go with a single CD player but what he wants is a multiple CD player. Does a beast like this exist? And if so, what is the best one?