That being said, perhaps a Vandersteen 2w/q sub with crossover will help? By employing a high pass filter, you relieve the amp from having tto reproduce power draining low frequencies.
Yep. You're telling me the truth that I don't want to face. I need to change either the amp or the speakers. I don't want to get away from 300b, but I'm also sad to sell my favorite speakers or relegate them to the closet. The best solution is Cary's 211 monoblocks, but I can't foresee when I'll have $22,000 to spare. A subwoofer is just going to introduce a new set of challenges.
Try and find a pre owned zero feedback Ayre AX7 integrated
I think you will be surprised at how much of the sound you are looking for comes from the Zero feedback design itself.
You may even discover some advantages with it and the Choices it allows with quality or performance & speakers you can now drive.
How did you end up in this situation? I considered a 7 watt SET but thought my room too big. Seems like SET is a midrange dream. My current amp has a SET output option. But I stick with Pentode. Thats me though. Your tastes may be towards the midrange magic of SET. Seems like yer going to have to make a decision. Amp, or speaker.....unless you can Bi-amp. Get a separate amp to push the other side. Not sure if that is feasible though. We audiophools are really a different bunch aren't we? Most people are satisfied listening to streaming music. We want it all!!. I wish you well in your search.