I have a Pioneer SC-25, it uses Wolfson WM8740 DACs. I am thinking of adding an outboard DAC, between that and my Fireball music server. I looked at the Cambridge Audio DAC Magic it also uses the Wolfson WM8740 DACs. Is there a difference between the two? Do I need to spend a lot more on a DAC than the DAC Magic to see a big improvement over the Pioneer?