what problem (technical, aesthetics, prestige) are you trying to solve? what brand your tube amp is, how much power etc?
good audiophile quality brands have good PC included, and only need to replace if broken etc..
10 gauge power cord. Too much power for tube amp?
Tube amplifiers tend to be sensitive on incoming voltages. Is there a chance a bigger gauge power cord like 10 gauge may not be a good thing?
My amplifier tends to shut down occasionally upon start up. maybe moving to a higher gauge might be better. Does it matter?