Vintage tube amp resurrection with Variac?
I have acquired some vintage tube equipment that has not been turned on for several decades. I bought a Variac on eBay having read many times to be sure to "bring up" old tube gear "slowly on a Variac". What exactly constitutes "bring up slowly"? Is it some sort of staging perhaps? If so, what voltage at each stage, number of stages, how long per stage. Or does it mean to continuously, but very slowly, crank the Variac from 0 to 117 volts?