I had the Pass Aleph 2's (then XA160's and awaiting the new XA100.5's). I replaced the stock power cords with two runs of 15' of JPS Labs in-wall cables wired directly from separate 20amp circuit breakers, through the floor, to high quality Furutech plugs directly into each momoblock. The drop in noise floor and resulting low-level detail retrieval was dramatic. Dynamics and transperancy also improved. I don't really know if the improvement is from the quality of the JPS cable or the fact that the current runs a direct path to the amps, ie. one continuous cable with no breaks for outlets and connectors. Cost was about $500.
