To the OP-
take your 57, put it right up to the grill, and have it pointed straight at the center of the cone. Record about 10 seconds worth of playing, then turn the head of the mic about 1" off axis, record another 10 seconds (preferably the same riff or playing). Repeat this until you reach the edge of the speaker cone, then listen to the playback. I'll bet you're gonna hear a HUGE difference in the tone through those snippets (should be 6-7 snippets), and one of those is going to be the speaker's sweet spot-it will be pretty obvious to your ears once you hear it.
I use 57s on guitar cabs and snare drums, occasionally toms or even a kick or overhead in a pinch, and have used them for vocals-if you stay about 6" off the mic, it sounds a fair amount like an SM7B (yes I actually did this comparison myself!). 57s are VERY sensitive to placement, more so than a lot of mics I've used over the years, and take some time and experimentation to really dial them in-but when you do, it's a sound you instantly recognize from a zillion records.
Good luck, and don't give up on that mic-it's an industry standard for a reason!
thank you. this is the most helpful post in this thread. i have not done this yet. probably others assumed i already did this but i have not. im a little slow sometimes. a lot to learn.
likely i have not always had the placement optimal.