Hi, I currently use an Arcam Alpha 10 with B&W 685s (not the new version). I mainly play vinyl on a Rega RP3. Thinking of replacing the speakers, would spending £500 second hand get me a significant improvement in sound? Mainly listen at low volumes. Been thinking along the lines of the Kef ls50, PMC db1i and the new version 685s but not heard any of them yet. Suggestions/ opinions welcome!