I compared a 100w / Channel Shiit Vidar against a 50W / Crown amp. The Vidar had slightly more low-end punch, but the 45yr old 50W Crown amp left it behind when it came to loudness with no distortion. I am not sure why? When I got a 30W tube amp running KT 77s it seems louder than both with greater dynamics. I was amazed, but happy! I think tubes have higher gain. I am sure some electrical engineer could explain.