It’s relative to the speaker that is being used. But, newer McIntosh tube amps enjoy the benefit of the use of a stable wide bandwidth unity output transformer, which greatly enhances overall performance to include bass. The new 275 has 4, 8, and 16 ohm taps which allows for impedance matching to whatever speakers you are using.
Although not a MC275, my MC2301s mated with my older 89db efficient B&W 800 Nautilus speakers had great deep non muddy bass.
I believe that with the MC275 and its various output taps, and the stable power that it is known for, you will be enjoying music. Remember that bookshelf speakers can only produce so much bass...and depending on the size, you are already at a deficit of bass capability based on size alone.
IME, your bookshelf speaker and it’s size will be a major factor in how much bass is produced. I have used Radio Shack bookshelf, B&W bookshelf, Klipsch bookshelves, and no matter if a tube or solid state driving them, the sound of bass coming from the bookshelf seemed to be repeatedly the same. I liked the old Altec or Advent bookshelves which seemed to have a kick to the bass.
