In my humble opinion, if a better power cable causes your system to sound fuller (better bass definition), then that is a strong indicator of a weakness in the Amplifier's Power Supply. Essentially the main Power Capacitors have either dried out or are leaking more than the manufacturer specifications. For Krell units, the recommended restoration cycle is around 10 to 15 years i.e. that's when a capacitor replacement becomes due.
20amp Power Cord for $18
My old KSA-250 came without its 20 amp power cord - as as I'm sure you know even a "cheap" such audiophile cord will set you back $300 and some thousands. Was considering hard wiring but also I set out on search for a good quality but unshielded good one. It was difficult but finally found one on amazon for under $18 (5-20P to C13 Power Cord, 6 Foot, 20A, 125V, 12/3 SJT - from Iron Box).
Just FYI if you are skeptical about cords for the 1% like I am.
Just FYI if you are skeptical about cords for the 1% like I am.