Hi Audiolabyrinth
It depends on your tube amplifier you want to try the tube rolling or power cord swapping with. I have a Jolida JD-502P tube amplifier and when I spoke to Jolida they told me the change that made the most difference sound wise was rolling with 12AX7 tubes. A buddy of mine who has a different amplifier found power tube rolling and a power cord change improved the sound in his system. I say call the maker of your tube amp to see and then experiment on your own.
It depends on your tube amplifier you want to try the tube rolling or power cord swapping with. I have a Jolida JD-502P tube amplifier and when I spoke to Jolida they told me the change that made the most difference sound wise was rolling with 12AX7 tubes. A buddy of mine who has a different amplifier found power tube rolling and a power cord change improved the sound in his system. I say call the maker of your tube amp to see and then experiment on your own.