@curiousjim I can think of only 3 possibilities.
1. your amp has a power supply that stores power for dynamics and bass in capacitors, chokes or other passive devices so tthat a large power cord isn't needed. this is most likely.
2. you're listening isn't good. Not likely. You're a veteran.
3. your system sucks so bad it doesn't help also extremely unlikely.
If you have a power problem with your amp, it will be immediately obvious when you install a $30 10awg power cable from ebay.
Now other components, such as DACs and streamers, have such minor power needs that it isn't unusual for a power cord upgrade not to change anything.
Jerry