"But as important as the 870A's power is its quality of sound -- ballsy, gutsy, and authoritative in the tradition of high-powered solid-state amplification, yet with a top end that sounds not only ultraclean, but rich to the point of being golden in tone. The 870A's midrange is also subtly richer and warmer than solid-state is normally thought to sound, and it can create a soundscape that's up there with the best in terms of size and image specificity."