power cords and krell amps any suggestions?

I'm thinking about upgrading form the stock cord for both of my amps a Ksa 200s and a Kav-500 3. We are using the Audioprism
Power Foundation lll, I also have 2 20 amp dedicated circuts for the system with the orange heavy duty recepticals. Which power cords have you tried and what were the results? Or would I be better served upgrading my recepticals first? I would like to here from Krell owners but of course all imput would be helpful.
Thanks for your help.
You might want to try a P.S. Audio Lab cable. It made a significant improvement on a KAV250 I had. Go to their website;they have a free 30 day trial & the price is very reasonable. I am using Syn. Research on all my front end components but I liked the results I got with the Lab cable on the amp & it cost a lot less. My new Krell amps have a captive cable but if they did'nt I would use the Lab cable on them. Larry w.
I also have the krell 200s and I use electraglide fatboy with great results. Opens the soundstage and provides deeper
I second the recomendation of Shunyata PC on Krells, I'm using a Shunyata Mojave on my FPB 200 and it just sounds right. The FIM Gold and ESP essence are also great on Krells.
I am listening to Krell KAV-250a and KPS-25sc. I upgraded the power cords to Siltech SPO-18 one meter cords and thought the difference was slight but definitely more musical and relaxed. The difference is noticeable in an A/B comparison. E-mail me privately if you would like the name of the person who got me the cables at a very good price. I don't know anything about the AC coming into my house but it is a new home.
I've been using Granite Audio 560 cords for my KAV-250 & 250 a/3.

Can't quite forget that first time--swapped out a cord, put on a CD, and my jaw dropped. :)

Haven't compared to many other similarly priced cords though. . .