Bryston 3B Amp VS Cambridge A300 Integrated Amp

Before I got Bryston 3B hooked up into my system, I appreciated A300' sound, it rated 50Watt into 8 Ohm, and 91db speaker then I upgraded Bryston 3B rated 100Watt into 8 Ohm. I am so disappointed how the Bryston 3B sounded, If you are audiophile, when you replaced a bigger amp into a system one thing U will notice is that at the same volume the speaker will sound louder approximately double. Right now I don't know how to do. The different b/w 2 is that Bryston just more a bit bass, the loudness of both the same. I appreciate for your attentions.