@prashanth13485 , the preamp section in the Ruby is quite good, but you could put something in front of the amp and change up the flavor. I'm going to try this myself, as I own the Ruby. I've been pretty smitten with it that I haven't put in a preamp yet. When I do, I'm going to put a tube preamp in front of it so as to try to hear a big difference in sound.
Would you consider going to a tube preamp?