I have owned the Belles Ref 150 and 350's and they are awesome but NOT tube sounding. I am a tube amp lover and will tell you based on my experience here are some better choices. I have owned many, many amps and do have some experience in this area.
Conrad Johnson 2500A
Any of the newer Electrocompaniet amps
Both of these will fit your needs.
Conrad Johnson 2500A
Any of the newer Electrocompaniet amps
Both of these will fit your needs.