I'm looking for some advice please......... I currently have a Pioneer NSDV88 all in one, but at some stage in the not too distant future, I fancy upgrading to something with Dolby Pro Logic II, DTS 6.1 and possibly SACD. What I want to know is, can I buy a new amp, and connect my existing Pioneer sub and speakers to it, or will I need to replace those as well ? I'm quite happy with the Pioneer DVD player for the time being, so could I just connect this to the new amp using an optical lead ? Any advice gratefully accepted !