For a couple years, I used a Shindo Cortese 10-watt SET amp with my Athenas, in combination with a Shindo Monbrison preamp. I also heard this combo easily drive a Ulysses. The Shindo put out 10 very powerful watts and I never exceeded 10 or 11 on my volume dial. The sound was absolutely room-filling in my medium sized listening room (21 x 13) with openings to other rooms.
The Shindo sonics were very immediate (as you would expect) and incredibly chunky and saturated with tone color. Eventually, I tried some solid state designs I liked and am now very happy with a Crayon CFA 1.2 integrated. Not quite the tone density of the Shindo gear, but significantly more transparent, with less coloration, and better bass.
I've had a half dozen or so amps come through the listening room with Lou's Athenas, and sonic differences were very easy to hear -- Lou's speakers are very transparent to what precedes them.