Hi everyone, hope you're all OK with what's happening right now. My question is about reading voltage on tube socket with a meter. I'm pretty sure that i've already read this in the past on this website, but just to be sure as i did'nt found my answer: can i put out all tubes (3 x 12ax7 preamp tubes and 2 x power tubes), power on the amp, stand by switch at off and be able to read all infos about plate (pin 3), screen and control grid (pin 4 and 5), cathode current (pin 8) without all tubes into my amp? Is that can be done without damage anything on the amp? Is there any advantage doing this or it's better to do this with all tubes? Thanks and have a nice day!