I'm using a pair of 6EM7 single ended triode monoblocks from Ultra Fi and they are excellent! Maybe they would meet your needs? You can see them if you look in virtual systems for Studio Ultra Fi.
EM7 Music Reference Amplifier
Have you heard or do you own this Music Reference amp? If so, what are your thoughts? Do you still own it? If so, what did it replace? If not, why did you part with it?