on a tube amp whether you cut your standby switch or power swithch off first?
when you turn it on, its always standby, then power. off would theoretically be the same. thats what i've seen most people doing.
i put mine in standby before i turn the power off.
always use standby when turning on or off, but wait a few minutes when turning on so the tubes heat up, turning off you can just go standby>>off with no waiting