Do I need 10 gauge power cord if I have 10 gauge from panel?

No, you do not.

I will rephrase the question about the need for a 10 gauge power cable.

Would it be better to have a 10 gauge power cord that plugs into a 10 gauge dedicated circuit outlet?

Most things in this world we don’t really need but many a time it makes things better.

@jumia    No, I said there is no reason to match.  As long as your wires are big enough to comfortably carry the current being drawn.  It's that simple.

@jumia

I’m with @ghdprentice on this one:

"Only when comparing to other cords. This is not a pursuit with absolutes… maybe the desire, but we live in a world of imperfection."

As with many audio pursuits, experimentation is the key to success. Hopefully, you can get your hands on some good examples of premium PCs and give them a listen.

IMO, adding hospital grade plugs will have a larger sonic impact. I have 2 dedicated 20A lines for my stereo. It turns out that with everything running and playing music, 2 amps, preamp, phono-pre, dac, cdplayer, turntable, draws only 2.4 Amps. So, the 20 Amp circuits were unnecessary.