I've had a Microphone Parts S-12 kit for almost a year, and seeking inspiration to FINALLY assemble it (I've previously put together one of their Fox 460 tube mic kits, also w/ the RK-12 capsule) and use it on a song I'm recording, I came across this video. The S-12 made your mandolin literally jump out of the speakers! It was so 3-D! And the transient response felt pretty fast, but complimentary. Nice clarity! The SM57's also continue to surprise me (last time was a pair on a Steinway 6ft grand through API pre's), but the S-12 just completely out performed it on your demo, to my ears. I'm gonna put my kit together tomorrow! Thanks!
I have to say the S-12 is a surprisingly good microphone kit and I use it all the time. My latest acquisition has been some Ear Trumpet Labs Edwina condenser mics and I've been having a good time testing these. SM57's are really amazing microphones that you can use for almost anything in a pinch, I just love them. You will love the S-12, have fun!