I had an ARC LS25 that I replaced with a Pass X1. The Pass had better dynamics and was just better all around -- more refined. Associated equipment: Pass X350, Levinson 37/360S (later an Electrocompaniet EMC1) and Dunlavy SC-IV/A's. The LS25MKII might give the Pass a better run for the money. Really, though, I don't think you could go wrong with either preamp.
