I don't know about just upgrading the power cord. I have an old Max, and when I got a better power cord (BPT C-7), I used it in conjunction w/ a BPT BP-Jr, which is a balanced power unit. That combination gave VERY big improvements to the sound, not subtle at all. The benefit of going that route is you can plug other equipment into the BP-Jr as well. That said, I hope to try pc-rolling my Max in the near future, as I hope there are still significant improvements to be heard.