Alamrg, I think this Positive Feedback review excerpt could help explain why Jazdoc's PX-25 "ran out of gas at mid-high listening levels" with his Daedalus Ulysses:
Although I know that Lou did not design this speaker specifically for low-powered tubes, the Ulysses can certainly deliver when driven by them. Is your passion the gorgeous sound of low power tubes? If so this speaker can accommodate you, though within limits. I felt at the 12-watt push-pull Audio Space amp was probably at the lower limit of power you could use and still get realistic dynamics. The 28-watt 845 Consonance SET performed very nicely.
How about mid- to high-power solid-state or tube designs? The Ulysses was built for high power. When I used 15 watts of class D power I loved the unlimited realistic dynamics that made the music seem so natural. My only regret was I didn't have a chance to try this speaker with some high-power tube amps.
Which type of amplification/source did I prefer with the Ulysses? Usually, whatever I was listening to at the time. Pressed for a decision on one, I have to give the nod to the Consonance Cyber 845, and my analog rig (VPI Scoutmaster, Shelter 501, and Aqvox Phono 2Ci, Gingko Cloud 9) which together gave me some of the most extraordinarily cohesive sound my room has ever been graced with. If you read Lou Hinkley's quote "coupling high efficiency with high power handling makes for effortless reproduction of music" it is obvious that he prefers a high-power amp for these speakers. I look at the Ulysses low-power affability as a big plus. This chameleon-like transducer is friendly to many different types of amps, and it truly lets you enjoy the characteristics of each and every amp. Rare indeed and a dream for audiophiles who enjoy the sound of more than one type of gain device.