I have the FPB200 (with 20 amp cord from Krell) but this is the smalles Krell power that will work and its not a problem...I did try replacing the FPB400cx and it trips, I believe thats the reason why. It was a loan so I was not prepared to try in for longer sessions but I believe and minimal volume it will play but when you demand the power...its not going to fly.
Rshad0000, out of curiosity which Krell were you using that actually worked on the 15 amp socket? Any of the FPB family by chance?