Are there any circuits in which the gain control really alters the voltage gain directly? Most circuits I see have a fixed-gain amplifying stage followed by an adjustable voltage divider. I know that in math, A X 10 X 0.3 = 3A, and 3 x A = 3A. Is there any practical difference in electronics whether you boost a signal by a large amount and then use a small fraction of it, VS boosting it by a small amount and then use all of it? It does seem like the 'fuzz' control on a Fuzz Face is sort-of a direct control on gain.