single rectifier output and master volume help

[vaccaroc]

I seem to get the sound i want out of the single rec when i dime out the output control and just barely open up master or adjust master just good enough to get whatever room volume im needing at that given time,is this safe to do or am i looking at blowing a tube,also i'm new to tube amps kinda sorta,I've been on the eleven rack kick for quite some time