There are a lot of ways to go here and budget and component matching are going to be extremely important. I agree with @jasonbourne71 , your speakers may be your limiting step right now. B&W have a strong house sound and that sound, to me, is on the extremely revealing/bright side. Many B&W owners temper this by using a tubey sounding tube amp like a McIntosh. The biggest single contributed to how your system sounds is going to be good speakers. I might spend some time going around and listening to different speakers. Don't just listen for 5 minutes either, listen for as long as they'll let you. Speakers are like TVs at Best buy. They turn the brightness and contrast all the way up on those TVs to make them pop on the wall, but when you get them home you realize this hurts your eyes and adjust the settings. The brightest most detailed speakers will pop in the store but then when you return them home you may realize they are fatiguing. I say all this to say that make sure you have the right speakers before you go spending thousands on electronics that will never fix the problem.
If you find you do like the speakers then what is your budget? I agree that changing your preamp would be the next step. There are lots of great units on the used market and that's where I'd look to get best bang for buck but first need to know how much you want to spend.