Years ago, I bought a kit from Granelli and did the conversion myself. I'm not sure if they still offer that option.Granelli Audio Labs dose the conversion. Its called a 5790. I had three of the regular SM57s and sometimes I had to compromise placement on snares due to the long body plus the XLR connector. I like all the mics to be facing me and parallel to each other to avoid electronic phase issues. They talk about it in this book along with a million other things I didn't know. Great book for the home studio.