Adding tube buffer to Rotel instead of............

I have a dual use system with a Rotel 1068 pro for movies and I have a hybrid Sonic Frontiers SFL1 pre amp for two channel, if I were to add a MF tube buffer and sell off the Sonic would I expect good results? I am wanting the convenience of the Rotel but with a more refined sound that tubes provide, plus rack space would be gained....is this at all wise or should I leave things alone? Associated gear is listed under my system, thanks.