Power amp(2 channel)- Rotel RB1590
Power amp(5 channel)- Rotel RMB1585
Rotel amps are definitely not one that is recommended for 2 channel listening . tend to be be cold / sterile sound and give the listener fatigue.
seems you are trying to make a sub par amp better by putting an expensive power cord on it.
if you want better 2 channel sound, then i would look at getting a preamp with home theater bypass and a better 2 channel amp.