Why does the Marantz 10B Tuner sound so amazing ???

I am usually listen to rock , but I find my self mezmerized when I hear classical music on the 10B, the instruments sound so real and beautiful. I own many high end tuners but none have the musicality of the 10B . It simply Plays music like a fine musical instrument. What did they do in the design , parts etc. to make this piece sound so great ?