Third in a series of FAQ build basics. Here I discuss and outline how to go about choosing an output transformer for your build, and also go on to discuss the fundamentals of an OT's primary impedance. https://headfirstamplification.com https://www.facebook.com/headfirst.amplification https://www.facebook.com/groups/225949122469679 https://www.instagram.com/headfirst_amplification/ [email protected] 0:00 Intro 1:30 Cheat sheet table 3:30 Primary impedance Rule of thumb 7:33 Primary impedance basic theory 13:33 Outro