A little update:
I spent 2+ hours listening to Don's system with my new preamp this afternoon. Even though the tubes were not optimal (according to Don), and my preamp had played for a scant few hours, it sounded absolutely wonderful to me. I can only dream about how it will sound once it is fully broken in. String plucks, violins, snare drums, brushes on cymbals, piano, voices....incredible clarity yet not the least bright or artificial sounding.
After listening to my preamp with his KT-88 amp for 45 minutes, we switched out to my Nuprime IDA-8 100W Class D integrated amp/DAC. Holy shit. What a difference! The Nuprime is great for non-critical, background listening, or even for 2-channel TV sound. However, compared to Don's amp/preamp combination, the IDA-8 sounds flat, 2 dimensional, even tinny. Of course, I never expected much more from the Nuprime. After all, I got it for under $1000. No way can it compete against $5000+ in tube gear.
Now I can barely wait till I get back home to hook up my AVA 400R, Gustard X20u, my Adelphos speakers, and my Rythmik subwoofer....Just 10 more days....