Since the amp draws the most current it would be the logical place to start. But a recent test in HIFICRITIC showed a different picture. It appears that there is no logic whatsoever to power cord substutions. They used a high quality CD player [Marantz CD-7] and a Naim NAP 300 amp. In almost every cast the cables did considerably better with one than the other. In defiance of all expectations the highest score [65] on the CD player was achieved by an elcheapo generic cord out of the junk box. The highest score on the amp was 80, by a Russ Andrews silver cable, the most expensive of those tested at over a thousand Pounds for 1M. But on the CD its score was 37, one of the lowest. These results perhaps explain the debate over where to place the cords, everyone is judging by their own experience, which is what they should do. I myself am using upgraded cable on my system, in some cases it was a noticeable improvement , in others, not so clear. When a $1k power cable was substuded for the stock one on my transport I heard a noticeable improvement, but I am not prepared to pay anything like that. If I was determined to try this I would order one that could be returned or borrow one from a dealer or friend. If you have audio friends this would be a good place to try each others cords. I would spend my money on a dedicated line first and then on interconnects and speaker wires, where the results are more predictable.