Tube amp rough guidance sought

Hi all,

I've got an about10 year old pair of B&W 805's, a paradigm servo 15 sub, currently running through a NAD T770 amp that used to also drive surround speakers. I haven't owned a TV in years and haven't used the center/rears in years. I've come to the opinion that the 2.1 setup needs to be fairly loud to produce decent sound and is pretty lifeless and flat at low volumes. Currently in a decently large room, tile floor, but lots of soft stuff to break up reverb.

I listen to a variety of things as all would say but mostly jazz, blues, classic rock, latin music and contemporary stuff. From Jim Croce to Ella to Led Zeppelin to Jeff Buckley and a lot that is less well recorded.

In any case, I'm thinking more and more about tube amps as a way to get a warmer sound, more life at low volume, and more just ear pleasing delight. I'm not a slut for sonic purity and I don't love having to turn it up really loud to get rich sound and good energy.

I'm guessing a first step might be to find a local hi-fi shop and take my 805's in and just try some stuff? I'm also fully open to suggestions of all sorts including changing anything else in the system, "selling all that crap and starting over" or whatever else folks can come up with.