I auditioned the Corona C51 Integrated Amp as a potential replacement for my Boulder monoblocks. My speakers are demanding, Wilson Sashas, and I am using A DCS Dac. To my considerable surprise I found that I greatly enjoyed my system when using the C51. Music sounded more realistic, with a greater sense of acoustical space. Orchestral and piano music are spectacular with top notch recordings. I listen to many opera recordings and found the sound stages opening up with greater vocal definition. I purchased the C51 and as a music lover and listener of over 40 years have never enjoyed music more.