Hi Clavil, ICEpower modules of 501 and 312 are the same ASP1000. 201 uses if I recall correctly the ASP500. These are -- relatively speaking -- current modules. By 'previous generation' I really meant previous generations of end user products. For example, the Continuum 500 can be considered a newer generation product than the 501 monos, because of the more sophisticated pre-PS power management, in spite of being designed around the same ASP1000 ICEpower modules. Similarly, the original BC R100 and the newer Mk.2 versions use the same ASP1000 modules as far as I know, but the Mk.2 has pre-PS power management that the original did not have. The PC1 devices is designed to bridge 102, 201, 501, and C250 products to current generation performance. It is worth pointing out that different manufacturers/engineers evolve their class D creations along different lines, applying different strategies towards similar musical goals, and all operate within the constraints dictated by their respective pricepoints. A priori, it is impossible to decide which approaches will be most successful, and in the end, only our own individual ears can determine what is most suitable for our own system and musical preferences. G.