Shem, I am not sure what kind of mic cord a Shure
57 takes. A lot of good mics use XLR cables.
You might find ans XLR to 1/4" cable, or you
might have to get an XLR to XLR, in which case you would
need an adapter called an impedance matching transformer,
to go from XLR to 1/4" inch. Then you need an adapter
from 1/4" to 1/8". The main thing: Get a cable that
hooks up to your mic, and dont worry about the other end.
Take the cable itself to radio shack, they will set
you up> Cheers David