Thanks for the reflection on your Feliks 300B! What speakers do you have it paired with? Some 300B amps are designed as parallel SET making about 15W using 4 300B tubes to create a bit more drive. There are other SET designs like the LM805ia which use 300B tubes as drivers (805's for power stage) and produces 48W that may accomplish what you're asking about.
Is there a 300B type amp out there with some WATTS behind it?
I recently acquired a Feliks Audio Arioso 300B amp. To put it simply, it is incredible. I understand one way to tackle the issue of using SET amps is with high sensitivity speakers. Is there a 300B or something that gives you that same sound out there with power so you have more speaker options?