Somehow, my notes on this have disappeard, and searches online just give me the calculator, but don't show the formulas. I'm trying to figure out decibels, relative to a reference, i.e, what exactly 3 dBu is. I can't for the life of me remember the formula. I have the formula for finding dB in a system, dB = 10 log P1/P2, but I don't have the formula I need. I do remember something along the lines of putting for dBu, .775 = something log something, but I'm stumped. If anyone can help, I'd be eternally grateful.