That's a good point! In a real BF fender circuit, the reverb comes after the tone stack and the first two gain stages, but before the PI/power section. If you are playing clean, you could put the reverb between the amp and speaker and it should be close enough. If you are distorting a BF amp, which I actually do all the time with the real ones, putting it after the power amp distortion is not going to be right, and putting it before the tone stack won't be right either.