Cayin vs. Antique Sound Labs

I am lucky enough to have a Cayin ta-30 and ASL AQ1003DT. I have challenged them both by running them through Thiel 3.5s (inefficient). The ASL ran the Theils with depth and great imaging. The speakers were loud enough to fill a 18' x 28' room (but not to concert levels). Voice and instrumentals were stunning. On the other hand, the Cayin lost it's depth and I had a hard time seperating Norah Jones from her band. The Cayin also began to become one dimensional after 10:00 on the vol. knob. I ran the same JJ E34Ls through both to try and be fair. Has anyone else had an issue with the Cayin not opening up the soundstage with inefficient speakers?

I know these amps were not designed for these speakers but it says a lot for the ASL to clearly outperform one of the most positively reviewed tube amps the last few months. One thing the Cayin does have is build quality and looks (even with the tube cage on). It was an easy sell to the wife! The ASL looks nice but not thrilling. I was really hoping to use the Cayin in my main system. Does anyone have a suggestion for efficient speakers for the Cayin that will really show what this amp can do? FYI - Paul from Bizzy Bee is outstanding to work with and answered all of my Cayin questions (even though I didn't buy the amp from him)!