The answer is to use the best of either...a great preamp into any great amp will sound better than a mediocre anything. Tubes are different than SS, we all know that...but synergy is key. I use a tube preamp (Schiit Freya which is either passive SS or tube...always in tube mode unless I switch it to see if the tubes are OK) into either a single ended Dennis Had amp or a Pass XA-25 class A amp...mostly the Pass as I'm lazy, but I put the Had amp in there and enjoy it when I feel like it. Tube amps aren't always better as it depends on the quality of the amp.