I did this only once. I was given the time critical task of redesigning at Class T to a Class D audio amplifier. Class T is just an upgraded Class D made by Tripath, who filed bankruptcy, hence the reason for the redesign. I read quite a bit about amplifiers, audio electronics, and the Class T. After all my frantic research, I made a modified Class D that was adequate. And met the deadline, so as to not interrupt the supply.
I really felt like my job was at stake, or at least that is how they made it seem. Has a job ever made you panic, and forced you to spend an evening sweating it out over books to learn some esoteric knowledge? Like a college cram session, but this time it's a matter of money and not a grade.
Cabe