Best Tube Amp for High Sensitivity Speakers: 45, PX25, or 300B?

elliottbnewcombjr:  That would probably be the best way to go. However, I do know there are quite a few 300B mono blocks, but I've not seen a single example of the 45 and PX25 doing the same.  Those tubes get such high marks, it would seem like a good path, but I'm not an engineer.  The tube amp systems that run in the tens of thousands never employ them... There must be a reason.  I do know that some of these run hot, but that's speculation.

This thread has gone away from the low power SET which the OP asked about.  His speakers will be fine with 2 wpc or even 1.8 which is the normal output from a 45 SET.

I'm driving my 96dB speakers with 2 wpc and while I listen at moderate volumes, I watch movies at theatre level and I'm driving the fron speakers during movies with the 2 wpc amp.

Many of the suggestions in this thread are the push/pull design that he is trying to get away from in the Primaluna.  These higher power tube amps are needed for those people trying to use tube amps with the currently ubiquitous 88-92 dB sensitive speakers.

Jerry

Does it really matter though if the tube amp is low power SET or push/pull design as long it sounds good? I would keep an open mind. There are excellent push/pull design just as there are excellent SET design. If budget is not an issue, I would have recommended that the Silbatone SET amps to be considered. They are wonderful as well. I stand by my recommendation of Lab12 Integre 4 MKII, it really equals high-end amps in the $20000+ range. There are also other options like Leben CS-600 and Audio Note Cobra, but I think the Lab12 is the best in its class already. 

Thank you, Jerry.  You've effectively brought it back to the parameters of my original query.  I wanted to find answers to comparing low-watt valve systems and what the community thinks about these different valves.  I reduced the valve listing to three for a reason; I didn't just want everyone to tout their amps.  I already have a nice Swiss-Army valve amp.  I wanted to fine-tune the question to specific, high-end valves that render extraordinary clarity, dimensionality, breathtaking musicality, and live tangibility that the best valves can produce in conditions that can best employ them (high-sensitivity speakers). I lived in Europe (mostly Spain) for twenty years, studied production with the BBC under Queens College Cambridge, loved the British sound, and built a media company in Spain.  When I sold it all to return to the States, I hoped to one day reach that level of vicarious, tangible music listening that would exceed the most memorable moments in my past professional life.  This is my "end-game" system.  I am building a room just for it (as many here have done).  I am not as interested in thundering power as in palpable envelopment. Music takes me places, on journeys. For a special moment, I am with the creators and craftsmen as closely as possible. They are with me. There are special tubes that are sweeter, more sensitive to the nuances of music than others. I'm on that search for the right balance between dynamics, musical depth, and analog believability as many of us are. And like many of my forum compatriots, I don't want to poorly spend my precious investment on frustrating experiments and regrettable explorations.

Depending too your budget and type of musicyulike and speakers