Google "balanced power for tube amplifiers" and see how far that rabbit hole goes ...
(And it's not all superstition, and it's not all for tube amps -- it's all in the SNRR of your power stages for every piece of equipment in your sound chain.)
(And it's not all superstition, and it's not all for tube amps -- it's all in the SNRR of your power stages for every piece of equipment in your sound chain.)